Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 4643 insertions, 0 deletions

diff --git a/src/rocksdb/db/db_basic_test.cc b/src/rocksdb/db/db_basic_test.cc
new file mode 100644
index 000000000..a28ac2b88
--- /dev/null
+++ b/src/rocksdb/db/db_basic_test.cc
@@ -0,0 +1,4643 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#include <cstring>
+
+#include "db/db_test_util.h"
+#include "options/options_helper.h"
+#include "port/stack_trace.h"
+#include "rocksdb/filter_policy.h"
+#include "rocksdb/flush_block_policy.h"
+#include "rocksdb/merge_operator.h"
+#include "rocksdb/perf_context.h"
+#include "rocksdb/table.h"
+#include "rocksdb/utilities/debug.h"
+#include "table/block_based/block_based_table_reader.h"
+#include "table/block_based/block_builder.h"
+#if !defined(ROCKSDB_LITE)
+#include "test_util/sync_point.h"
+#endif
+#include "util/file_checksum_helper.h"
+#include "util/random.h"
+#include "utilities/counted_fs.h"
+#include "utilities/fault_injection_env.h"
+#include "utilities/merge_operators.h"
+#include "utilities/merge_operators/string_append/stringappend.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+class DBBasicTest : public DBTestBase {
+ public:
+  DBBasicTest() : DBTestBase("db_basic_test", /*env_do_fsync=*/false) {}
+};
+
+TEST_F(DBBasicTest, OpenWhenOpen) {
+  Options options = CurrentOptions();
+  options.env = env_;
+  DB* db2 = nullptr;
+  Status s = DB::Open(options, dbname_, &db2);
+  ASSERT_NOK(s) << [db2]() {
+    delete db2;
+    return "db2 open: ok";
+  }();
+  ASSERT_EQ(Status::Code::kIOError, s.code());
+  ASSERT_EQ(Status::SubCode::kNone, s.subcode());
+  ASSERT_TRUE(strstr(s.getState(), "lock ") != nullptr);
+
+  delete db2;
+}
+
+TEST_F(DBBasicTest, EnableDirectIOWithZeroBuf) {
+  if (!IsDirectIOSupported()) {
+    ROCKSDB_GTEST_BYPASS("Direct IO not supported");
+    return;
+  }
+  Options options = GetDefaultOptions();
+  options.create_if_missing = true;
+  options.use_direct_io_for_flush_and_compaction = true;
+  options.writable_file_max_buffer_size = 0;
+  ASSERT_TRUE(TryReopen(options).IsInvalidArgument());
+
+  options.writable_file_max_buffer_size = 1024;
+  Reopen(options);
+  const std::unordered_map<std::string, std::string> new_db_opts = {
+      {"writable_file_max_buffer_size", "0"}};
+  ASSERT_TRUE(db_->SetDBOptions(new_db_opts).IsInvalidArgument());
+}
+
+TEST_F(DBBasicTest, UniqueSession) {
+  Options options = CurrentOptions();
+  std::string sid1, sid2, sid3, sid4;
+
+  ASSERT_OK(db_->GetDbSessionId(sid1));
+  Reopen(options);
+  ASSERT_OK(db_->GetDbSessionId(sid2));
+  ASSERT_OK(Put("foo", "v1"));
+  ASSERT_OK(db_->GetDbSessionId(sid4));
+  Reopen(options);
+  ASSERT_OK(db_->GetDbSessionId(sid3));
+
+  ASSERT_NE(sid1, sid2);
+  ASSERT_NE(sid1, sid3);
+  ASSERT_NE(sid2, sid3);
+
+  ASSERT_EQ(sid2, sid4);
+
+  // Expected compact format for session ids (see notes in implementation)
+  TestRegex expected("[0-9A-Z]{20}");
+  EXPECT_MATCHES_REGEX(sid1, expected);
+  EXPECT_MATCHES_REGEX(sid2, expected);
+  EXPECT_MATCHES_REGEX(sid3, expected);
+
+#ifndef ROCKSDB_LITE
+  Close();
+  ASSERT_OK(ReadOnlyReopen(options));
+  ASSERT_OK(db_->GetDbSessionId(sid1));
+  // Test uniqueness between readonly open (sid1) and regular open (sid3)
+  ASSERT_NE(sid1, sid3);
+  Close();
+  ASSERT_OK(ReadOnlyReopen(options));
+  ASSERT_OK(db_->GetDbSessionId(sid2));
+  ASSERT_EQ("v1", Get("foo"));
+  ASSERT_OK(db_->GetDbSessionId(sid3));
+
+  ASSERT_NE(sid1, sid2);
+
+  ASSERT_EQ(sid2, sid3);
+#endif  // ROCKSDB_LITE
+
+  CreateAndReopenWithCF({"goku"}, options);
+  ASSERT_OK(db_->GetDbSessionId(sid1));
+  ASSERT_OK(Put("bar", "e1"));
+  ASSERT_OK(db_->GetDbSessionId(sid2));
+  ASSERT_EQ("e1", Get("bar"));
+  ASSERT_OK(db_->GetDbSessionId(sid3));
+  ReopenWithColumnFamilies({"default", "goku"}, options);
+  ASSERT_OK(db_->GetDbSessionId(sid4));
+
+  ASSERT_EQ(sid1, sid2);
+  ASSERT_EQ(sid2, sid3);
+
+  ASSERT_NE(sid1, sid4);
+}
+
+#ifndef ROCKSDB_LITE
+TEST_F(DBBasicTest, ReadOnlyDB) {
+  ASSERT_OK(Put("foo", "v1"));
+  ASSERT_OK(Put("bar", "v2"));
+  ASSERT_OK(Put("foo", "v3"));
+  Close();
+
+  auto verify_one_iter = [&](Iterator* iter) {
+    int count = 0;
+    for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
+      ASSERT_OK(iter->status());
+      ++count;
+    }
+    // Always expect two keys: "foo" and "bar"
+    ASSERT_EQ(count, 2);
+  };
+
+  auto verify_all_iters = [&]() {
+    Iterator* iter = db_->NewIterator(ReadOptions());
+    verify_one_iter(iter);
+    delete iter;
+
+    std::vector<Iterator*> iters;
+    ASSERT_OK(db_->NewIterators(ReadOptions(),
+                                {dbfull()->DefaultColumnFamily()}, &iters));
+    ASSERT_EQ(static_cast<uint64_t>(1), iters.size());
+    verify_one_iter(iters[0]);
+    delete iters[0];
+  };
+
+  auto options = CurrentOptions();
+  assert(options.env == env_);
+  ASSERT_OK(ReadOnlyReopen(options));
+  ASSERT_EQ("v3", Get("foo"));
+  ASSERT_EQ("v2", Get("bar"));
+  verify_all_iters();
+  Close();
+
+  // Reopen and flush memtable.
+  Reopen(options);
+  ASSERT_OK(Flush());
+  Close();
+  // Now check keys in read only mode.
+  ASSERT_OK(ReadOnlyReopen(options));
+  ASSERT_EQ("v3", Get("foo"));
+  ASSERT_EQ("v2", Get("bar"));
+  verify_all_iters();
+  ASSERT_TRUE(db_->SyncWAL().IsNotSupported());
+}
+
+// TODO akanksha: Update the test to check that combination
+// does not actually write to FS (use open read-only with
+// CompositeEnvWrapper+ReadOnlyFileSystem).
+TEST_F(DBBasicTest, DISABLED_ReadOnlyDBWithWriteDBIdToManifestSet) {
+  ASSERT_OK(Put("foo", "v1"));
+  ASSERT_OK(Put("bar", "v2"));
+  ASSERT_OK(Put("foo", "v3"));
+  Close();
+
+  auto options = CurrentOptions();
+  options.write_dbid_to_manifest = true;
+  assert(options.env == env_);
+  ASSERT_OK(ReadOnlyReopen(options));
+  std::string db_id1;
+  ASSERT_OK(db_->GetDbIdentity(db_id1));
+  ASSERT_EQ("v3", Get("foo"));
+  ASSERT_EQ("v2", Get("bar"));
+  Iterator* iter = db_->NewIterator(ReadOptions());
+  int count = 0;
+  for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
+    ASSERT_OK(iter->status());
+    ++count;
+  }
+  ASSERT_EQ(count, 2);
+  delete iter;
+  Close();
+
+  // Reopen and flush memtable.
+  Reopen(options);
+  ASSERT_OK(Flush());
+  Close();
+  // Now check keys in read only mode.
+  ASSERT_OK(ReadOnlyReopen(options));
+  ASSERT_EQ("v3", Get("foo"));
+  ASSERT_EQ("v2", Get("bar"));
+  ASSERT_TRUE(db_->SyncWAL().IsNotSupported());
+  std::string db_id2;
+  ASSERT_OK(db_->GetDbIdentity(db_id2));
+  ASSERT_EQ(db_id1, db_id2);
+}
+
+TEST_F(DBBasicTest, CompactedDB) {
+  const uint64_t kFileSize = 1 << 20;
+  Options options = CurrentOptions();
+  options.disable_auto_compactions = true;
+  options.write_buffer_size = kFileSize;
+  options.target_file_size_base = kFileSize;
+  options.max_bytes_for_level_base = 1 << 30;
+  options.compression = kNoCompression;
+  Reopen(options);
+  // 1 L0 file, use CompactedDB if max_open_files = -1
+  ASSERT_OK(Put("aaa", DummyString(kFileSize / 2, '1')));
+  ASSERT_OK(Flush());
+  Close();
+  ASSERT_OK(ReadOnlyReopen(options));
+  Status s = Put("new", "value");
+  ASSERT_EQ(s.ToString(),
+            "Not implemented: Not supported operation in read only mode.");
+  ASSERT_EQ(DummyString(kFileSize / 2, '1'), Get("aaa"));
+  Close();
+  options.max_open_files = -1;
+  ASSERT_OK(ReadOnlyReopen(options));
+  s = Put("new", "value");
+  ASSERT_EQ(s.ToString(),
+            "Not implemented: Not supported in compacted db mode.");
+  ASSERT_EQ(DummyString(kFileSize / 2, '1'), Get("aaa"));
+  Close();
+  Reopen(options);
+  // Add more L0 files
+  ASSERT_OK(Put("bbb", DummyString(kFileSize / 2, '2')));
+  ASSERT_OK(Flush());
+  ASSERT_OK(Put("aaa", DummyString(kFileSize / 2, 'a')));
+  ASSERT_OK(Flush());
+  ASSERT_OK(Put("bbb", DummyString(kFileSize / 2, 'b')));
+  ASSERT_OK(Put("eee", DummyString(kFileSize / 2, 'e')));
+  ASSERT_OK(Flush());
+  ASSERT_OK(Put("something_not_flushed", "x"));
+  Close();
+
+  ASSERT_OK(ReadOnlyReopen(options));
+  // Fallback to read-only DB
+  s = Put("new", "value");
+  ASSERT_EQ(s.ToString(),
+            "Not implemented: Not supported operation in read only mode.");
+
+  // TODO: validate that other write ops return NotImplemented
+  // (DBImplReadOnly is missing some overrides)
+
+  // Ensure no deadlock on flush triggered by another API function
+  // (Old deadlock bug depends on something_not_flushed above.)
+  std::vector<std::string> files;
+  uint64_t manifest_file_size;
+  ASSERT_OK(db_->GetLiveFiles(files, &manifest_file_size, /*flush*/ true));
+  LiveFilesStorageInfoOptions lfsi_opts;
+  lfsi_opts.wal_size_for_flush = 0;  // always
+  std::vector<LiveFileStorageInfo> files2;
+  ASSERT_OK(db_->GetLiveFilesStorageInfo(lfsi_opts, &files2));
+
+  Close();
+
+  // Full compaction
+  Reopen(options);
+  // Add more keys
+  ASSERT_OK(Put("fff", DummyString(kFileSize / 2, 'f')));
+  ASSERT_OK(Put("hhh", DummyString(kFileSize / 2, 'h')));
+  ASSERT_OK(Put("iii", DummyString(kFileSize / 2, 'i')));
+  ASSERT_OK(Put("jjj", DummyString(kFileSize / 2, 'j')));
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), nullptr, nullptr));
+  ASSERT_EQ(3, NumTableFilesAtLevel(1));
+  Close();
+
+  // CompactedDB
+  ASSERT_OK(ReadOnlyReopen(options));
+  s = Put("new", "value");
+  ASSERT_EQ(s.ToString(),
+            "Not implemented: Not supported in compacted db mode.");
+  ASSERT_EQ("NOT_FOUND", Get("abc"));
+  ASSERT_EQ(DummyString(kFileSize / 2, 'a'), Get("aaa"));
+  ASSERT_EQ(DummyString(kFileSize / 2, 'b'), Get("bbb"));
+  ASSERT_EQ("NOT_FOUND", Get("ccc"));
+  ASSERT_EQ(DummyString(kFileSize / 2, 'e'), Get("eee"));
+  ASSERT_EQ(DummyString(kFileSize / 2, 'f'), Get("fff"));
+  ASSERT_EQ("NOT_FOUND", Get("ggg"));
+  ASSERT_EQ(DummyString(kFileSize / 2, 'h'), Get("hhh"));
+  ASSERT_EQ(DummyString(kFileSize / 2, 'i'), Get("iii"));
+  ASSERT_EQ(DummyString(kFileSize / 2, 'j'), Get("jjj"));
+  ASSERT_EQ("NOT_FOUND", Get("kkk"));
+
+  // TODO: validate that other write ops return NotImplemented
+  // (CompactedDB is missing some overrides)
+
+  // Ensure no deadlock on flush triggered by another API function
+  ASSERT_OK(db_->GetLiveFiles(files, &manifest_file_size, /*flush*/ true));
+  ASSERT_OK(db_->GetLiveFilesStorageInfo(lfsi_opts, &files2));
+
+  // MultiGet
+  std::vector<std::string> values;
+  std::vector<Status> status_list = dbfull()->MultiGet(
+      ReadOptions(),
+      std::vector<Slice>({Slice("aaa"), Slice("ccc"), Slice("eee"),
+                          Slice("ggg"), Slice("iii"), Slice("kkk")}),
+      &values);
+  ASSERT_EQ(status_list.size(), static_cast<uint64_t>(6));
+  ASSERT_EQ(values.size(), static_cast<uint64_t>(6));
+  ASSERT_OK(status_list[0]);
+  ASSERT_EQ(DummyString(kFileSize / 2, 'a'), values[0]);
+  ASSERT_TRUE(status_list[1].IsNotFound());
+  ASSERT_OK(status_list[2]);
+  ASSERT_EQ(DummyString(kFileSize / 2, 'e'), values[2]);
+  ASSERT_TRUE(status_list[3].IsNotFound());
+  ASSERT_OK(status_list[4]);
+  ASSERT_EQ(DummyString(kFileSize / 2, 'i'), values[4]);
+  ASSERT_TRUE(status_list[5].IsNotFound());
+
+  Reopen(options);
+  // Add a key
+  ASSERT_OK(Put("fff", DummyString(kFileSize / 2, 'f')));
+  Close();
+  ASSERT_OK(ReadOnlyReopen(options));
+  s = Put("new", "value");
+  ASSERT_EQ(s.ToString(),
+            "Not implemented: Not supported operation in read only mode.");
+}
+
+TEST_F(DBBasicTest, LevelLimitReopen) {
+  Options options = CurrentOptions();
+  CreateAndReopenWithCF({"pikachu"}, options);
+
+  const std::string value(1024 * 1024, ' ');
+  int i = 0;
+  while (NumTableFilesAtLevel(2, 1) == 0) {
+    ASSERT_OK(Put(1, Key(i++), value));
+    ASSERT_OK(dbfull()->TEST_WaitForFlushMemTable());
+    ASSERT_OK(dbfull()->TEST_WaitForCompact());
+  }
+
+  options.num_levels = 1;
+  options.max_bytes_for_level_multiplier_additional.resize(1, 1);
+  Status s = TryReopenWithColumnFamilies({"default", "pikachu"}, options);
+  ASSERT_EQ(s.IsInvalidArgument(), true);
+  ASSERT_EQ(s.ToString(),
+            "Invalid argument: db has more levels than options.num_levels");
+
+  options.num_levels = 10;
+  options.max_bytes_for_level_multiplier_additional.resize(10, 1);
+  ASSERT_OK(TryReopenWithColumnFamilies({"default", "pikachu"}, options));
+}
+#endif  // ROCKSDB_LITE
+
+TEST_F(DBBasicTest, PutDeleteGet) {
+  do {
+    CreateAndReopenWithCF({"pikachu"}, CurrentOptions());
+    ASSERT_OK(Put(1, "foo", "v1"));
+    ASSERT_EQ("v1", Get(1, "foo"));
+    ASSERT_OK(Put(1, "foo", "v2"));
+    ASSERT_EQ("v2", Get(1, "foo"));
+    ASSERT_OK(Delete(1, "foo"));
+    ASSERT_EQ("NOT_FOUND", Get(1, "foo"));
+  } while (ChangeOptions());
+}
+
+TEST_F(DBBasicTest, PutSingleDeleteGet) {
+  do {
+    CreateAndReopenWithCF({"pikachu"}, CurrentOptions());
+    ASSERT_OK(Put(1, "foo", "v1"));
+    ASSERT_EQ("v1", Get(1, "foo"));
+    ASSERT_OK(Put(1, "foo2", "v2"));
+    ASSERT_EQ("v2", Get(1, "foo2"));
+    ASSERT_OK(SingleDelete(1, "foo"));
+    ASSERT_EQ("NOT_FOUND", Get(1, "foo"));
+    // Ski FIFO and universal compaction because they do not apply to the test
+    // case. Skip MergePut because single delete does not get removed when it
+    // encounters a merge.
+  } while (ChangeOptions(kSkipFIFOCompaction | kSkipUniversalCompaction |
+                         kSkipMergePut));
+}
+
+TEST_F(DBBasicTest, EmptyFlush) {
+  // It is possible to produce empty flushes when using single deletes. Tests
+  // whether empty flushes cause issues.
+  do {
+    Random rnd(301);
+
+    Options options = CurrentOptions();
+    options.disable_auto_compactions = true;
+    CreateAndReopenWithCF({"pikachu"}, options);
+
+    ASSERT_OK(Put(1, "a", Slice()));
+    ASSERT_OK(SingleDelete(1, "a"));
+    ASSERT_OK(Flush(1));
+
+    ASSERT_EQ("[ ]", AllEntriesFor("a", 1));
+    // Skip FIFO and  universal compaction as they do not apply to the test
+    // case. Skip MergePut because merges cannot be combined with single
+    // deletions.
+  } while (ChangeOptions(kSkipFIFOCompaction | kSkipUniversalCompaction |
+                         kSkipMergePut));
+}
+
+TEST_F(DBBasicTest, GetFromVersions) {
+  do {
+    CreateAndReopenWithCF({"pikachu"}, CurrentOptions());
+    ASSERT_OK(Put(1, "foo", "v1"));
+    ASSERT_OK(Flush(1));
+    ASSERT_EQ("v1", Get(1, "foo"));
+    ASSERT_EQ("NOT_FOUND", Get(0, "foo"));
+  } while (ChangeOptions());
+}
+
+#ifndef ROCKSDB_LITE
+TEST_F(DBBasicTest, GetSnapshot) {
+  anon::OptionsOverride options_override;
+  options_override.skip_policy = kSkipNoSnapshot;
+  do {
+    CreateAndReopenWithCF({"pikachu"}, CurrentOptions(options_override));
+    // Try with both a short key and a long key
+    for (int i = 0; i < 2; i++) {
+      std::string key = (i == 0) ? std::string("foo") : std::string(200, 'x');
+      ASSERT_OK(Put(1, key, "v1"));
+      const Snapshot* s1 = db_->GetSnapshot();
+      ASSERT_OK(Put(1, key, "v2"));
+      ASSERT_EQ("v2", Get(1, key));
+      ASSERT_EQ("v1", Get(1, key, s1));
+      ASSERT_OK(Flush(1));
+      ASSERT_EQ("v2", Get(1, key));
+      ASSERT_EQ("v1", Get(1, key, s1));
+      db_->ReleaseSnapshot(s1);
+    }
+  } while (ChangeOptions());
+}
+#endif  // ROCKSDB_LITE
+
+TEST_F(DBBasicTest, CheckLock) {
+  do {
+    DB* localdb = nullptr;
+    Options options = CurrentOptions();
+    ASSERT_OK(TryReopen(options));
+
+    // second open should fail
+    Status s = DB::Open(options, dbname_, &localdb);
+    ASSERT_NOK(s) << [localdb]() {
+      delete localdb;
+      return "localdb open: ok";
+    }();
+#ifdef OS_LINUX
+    ASSERT_TRUE(s.ToString().find("lock ") != std::string::npos);
+#endif  // OS_LINUX
+  } while (ChangeCompactOptions());
+}
+
+TEST_F(DBBasicTest, FlushMultipleMemtable) {
+  do {
+    Options options = CurrentOptions();
+    WriteOptions writeOpt = WriteOptions();
+    writeOpt.disableWAL = true;
+    options.max_write_buffer_number = 4;
+    options.min_write_buffer_number_to_merge = 3;
+    options.max_write_buffer_size_to_maintain = -1;
+    CreateAndReopenWithCF({"pikachu"}, options);
+    ASSERT_OK(dbfull()->Put(writeOpt, handles_[1], "foo", "v1"));
+    ASSERT_OK(Flush(1));
+    ASSERT_OK(dbfull()->Put(writeOpt, handles_[1], "bar", "v1"));
+
+    ASSERT_EQ("v1", Get(1, "foo"));
+    ASSERT_EQ("v1", Get(1, "bar"));
+    ASSERT_OK(Flush(1));
+  } while (ChangeCompactOptions());
+}
+
+TEST_F(DBBasicTest, FlushEmptyColumnFamily) {
+  // Block flush thread and disable compaction thread
+  env_->SetBackgroundThreads(1, Env::HIGH);
+  env_->SetBackgroundThreads(1, Env::LOW);
+  test::SleepingBackgroundTask sleeping_task_low;
+  env_->Schedule(&test::SleepingBackgroundTask::DoSleepTask, &sleeping_task_low,
+                 Env::Priority::LOW);
+  test::SleepingBackgroundTask sleeping_task_high;
+  env_->Schedule(&test::SleepingBackgroundTask::DoSleepTask,
+                 &sleeping_task_high, Env::Priority::HIGH);
+
+  Options options = CurrentOptions();
+  // disable compaction
+  options.disable_auto_compactions = true;
+  WriteOptions writeOpt = WriteOptions();
+  writeOpt.disableWAL = true;
+  options.max_write_buffer_number = 2;
+  options.min_write_buffer_number_to_merge = 1;
+  options.max_write_buffer_size_to_maintain =
+      static_cast<int64_t>(options.write_buffer_size);
+  CreateAndReopenWithCF({"pikachu"}, options);
+
+  // Compaction can still go through even if no thread can flush the
+  // mem table.
+  ASSERT_OK(Flush(0));
+  ASSERT_OK(Flush(1));
+
+  // Insert can go through
+  ASSERT_OK(dbfull()->Put(writeOpt, handles_[0], "foo", "v1"));
+  ASSERT_OK(dbfull()->Put(writeOpt, handles_[1], "bar", "v1"));
+
+  ASSERT_EQ("v1", Get(0, "foo"));
+  ASSERT_EQ("v1", Get(1, "bar"));
+
+  sleeping_task_high.WakeUp();
+  sleeping_task_high.WaitUntilDone();
+
+  // Flush can still go through.
+  ASSERT_OK(Flush(0));
+  ASSERT_OK(Flush(1));
+
+  sleeping_task_low.WakeUp();
+  sleeping_task_low.WaitUntilDone();
+}
+
+TEST_F(DBBasicTest, Flush) {
+  do {
+    CreateAndReopenWithCF({"pikachu"}, CurrentOptions());
+    WriteOptions writeOpt = WriteOptions();
+    writeOpt.disableWAL = true;
+    SetPerfLevel(kEnableTime);
+    ASSERT_OK(dbfull()->Put(writeOpt, handles_[1], "foo", "v1"));
+    // this will now also flush the last 2 writes
+    ASSERT_OK(Flush(1));
+    ASSERT_OK(dbfull()->Put(writeOpt, handles_[1], "bar", "v1"));
+
+    get_perf_context()->Reset();
+    Get(1, "foo");
+    ASSERT_TRUE((int)get_perf_context()->get_from_output_files_time > 0);
+    ASSERT_EQ(2, (int)get_perf_context()->get_read_bytes);
+
+    ReopenWithColumnFamilies({"default", "pikachu"}, CurrentOptions());
+    ASSERT_EQ("v1", Get(1, "foo"));
+    ASSERT_EQ("v1", Get(1, "bar"));
+
+    writeOpt.disableWAL = true;
+    ASSERT_OK(dbfull()->Put(writeOpt, handles_[1], "bar", "v2"));
+    ASSERT_OK(dbfull()->Put(writeOpt, handles_[1], "foo", "v2"));
+    ASSERT_OK(Flush(1));
+
+    ReopenWithColumnFamilies({"default", "pikachu"}, CurrentOptions());
+    ASSERT_EQ("v2", Get(1, "bar"));
+    get_perf_context()->Reset();
+    ASSERT_EQ("v2", Get(1, "foo"));
+    ASSERT_TRUE((int)get_perf_context()->get_from_output_files_time > 0);
+
+    writeOpt.disableWAL = false;
+    ASSERT_OK(dbfull()->Put(writeOpt, handles_[1], "bar", "v3"));
+    ASSERT_OK(dbfull()->Put(writeOpt, handles_[1], "foo", "v3"));
+    ASSERT_OK(Flush(1));
+
+    ReopenWithColumnFamilies({"default", "pikachu"}, CurrentOptions());
+    // 'foo' should be there because its put
+    // has WAL enabled.
+    ASSERT_EQ("v3", Get(1, "foo"));
+    ASSERT_EQ("v3", Get(1, "bar"));
+
+    SetPerfLevel(kDisable);
+  } while (ChangeCompactOptions());
+}
+
+TEST_F(DBBasicTest, ManifestRollOver) {
+  do {
+    Options options;
+    options.max_manifest_file_size = 10;  // 10 bytes
+    options = CurrentOptions(options);
+    CreateAndReopenWithCF({"pikachu"}, options);
+    {
+      ASSERT_OK(Put(1, "manifest_key1", std::string(1000, '1')));
+      ASSERT_OK(Put(1, "manifest_key2", std::string(1000, '2')));
+      ASSERT_OK(Put(1, "manifest_key3", std::string(1000, '3')));
+      uint64_t manifest_before_flush = dbfull()->TEST_Current_Manifest_FileNo();
+      ASSERT_OK(Flush(1));  // This should trigger LogAndApply.
+      uint64_t manifest_after_flush = dbfull()->TEST_Current_Manifest_FileNo();
+      ASSERT_GT(manifest_after_flush, manifest_before_flush);
+      ReopenWithColumnFamilies({"default", "pikachu"}, options);
+      ASSERT_GT(dbfull()->TEST_Current_Manifest_FileNo(), manifest_after_flush);
+      // check if a new manifest file got inserted or not.
+      ASSERT_EQ(std::string(1000, '1'), Get(1, "manifest_key1"));
+      ASSERT_EQ(std::string(1000, '2'), Get(1, "manifest_key2"));
+      ASSERT_EQ(std::string(1000, '3'), Get(1, "manifest_key3"));
+    }
+  } while (ChangeCompactOptions());
+}
+
+TEST_F(DBBasicTest, IdentityAcrossRestarts) {
+  constexpr size_t kMinIdSize = 10;
+  do {
+    for (bool with_manifest : {false, true}) {
+      std::string idfilename = IdentityFileName(dbname_);
+      std::string id1, tmp;
+      ASSERT_OK(db_->GetDbIdentity(id1));
+      ASSERT_GE(id1.size(), kMinIdSize);
+
+      Options options = CurrentOptions();
+      options.write_dbid_to_manifest = with_manifest;
+      Reopen(options);
+      std::string id2;
+      ASSERT_OK(db_->GetDbIdentity(id2));
+      // id2 should match id1 because identity was not regenerated
+      ASSERT_EQ(id1, id2);
+      ASSERT_OK(ReadFileToString(env_, idfilename, &tmp));
+      ASSERT_EQ(tmp, id2);
+
+      // Recover from deleted/missing IDENTITY
+      ASSERT_OK(env_->DeleteFile(idfilename));
+      Reopen(options);
+      std::string id3;
+      ASSERT_OK(db_->GetDbIdentity(id3));
+      if (with_manifest) {
+        // id3 should match id1 because identity was restored from manifest
+        ASSERT_EQ(id1, id3);
+      } else {
+        // id3 should NOT match id1 because identity was regenerated
+        ASSERT_NE(id1, id3);
+        ASSERT_GE(id3.size(), kMinIdSize);
+      }
+      ASSERT_OK(ReadFileToString(env_, idfilename, &tmp));
+      ASSERT_EQ(tmp, id3);
+
+      // Recover from truncated IDENTITY
+      {
+        std::unique_ptr<WritableFile> w;
+        ASSERT_OK(env_->NewWritableFile(idfilename, &w, EnvOptions()));
+        ASSERT_OK(w->Close());
+      }
+      Reopen(options);
+      std::string id4;
+      ASSERT_OK(db_->GetDbIdentity(id4));
+      if (with_manifest) {
+        // id4 should match id1 because identity was restored from manifest
+        ASSERT_EQ(id1, id4);
+      } else {
+        // id4 should NOT match id1 because identity was regenerated
+        ASSERT_NE(id1, id4);
+        ASSERT_GE(id4.size(), kMinIdSize);
+      }
+      ASSERT_OK(ReadFileToString(env_, idfilename, &tmp));
+      ASSERT_EQ(tmp, id4);
+
+      // Recover from overwritten IDENTITY
+      std::string silly_id = "asdf123456789";
+      {
+        std::unique_ptr<WritableFile> w;
+        ASSERT_OK(env_->NewWritableFile(idfilename, &w, EnvOptions()));
+        ASSERT_OK(w->Append(silly_id));
+        ASSERT_OK(w->Close());
+      }
+      Reopen(options);
+      std::string id5;
+      ASSERT_OK(db_->GetDbIdentity(id5));
+      if (with_manifest) {
+        // id4 should match id1 because identity was restored from manifest
+        ASSERT_EQ(id1, id5);
+      } else {
+        ASSERT_EQ(id5, silly_id);
+      }
+      ASSERT_OK(ReadFileToString(env_, idfilename, &tmp));
+      ASSERT_EQ(tmp, id5);
+    }
+  } while (ChangeCompactOptions());
+}
+
+#ifndef ROCKSDB_LITE
+TEST_F(DBBasicTest, Snapshot) {
+  env_->SetMockSleep();
+  anon::OptionsOverride options_override;
+  options_override.skip_policy = kSkipNoSnapshot;
+  do {
+    CreateAndReopenWithCF({"pikachu"}, CurrentOptions(options_override));
+    ASSERT_OK(Put(0, "foo", "0v1"));
+    ASSERT_OK(Put(1, "foo", "1v1"));
+
+    const Snapshot* s1 = db_->GetSnapshot();
+    ASSERT_EQ(1U, GetNumSnapshots());
+    uint64_t time_snap1 = GetTimeOldestSnapshots();
+    ASSERT_GT(time_snap1, 0U);
+    ASSERT_EQ(GetSequenceOldestSnapshots(), s1->GetSequenceNumber());
+    ASSERT_OK(Put(0, "foo", "0v2"));
+    ASSERT_OK(Put(1, "foo", "1v2"));
+
+    env_->MockSleepForSeconds(1);
+
+    const Snapshot* s2 = db_->GetSnapshot();
+    ASSERT_EQ(2U, GetNumSnapshots());
+    ASSERT_EQ(time_snap1, GetTimeOldestSnapshots());
+    ASSERT_EQ(GetSequenceOldestSnapshots(), s1->GetSequenceNumber());
+    ASSERT_OK(Put(0, "foo", "0v3"));
+    ASSERT_OK(Put(1, "foo", "1v3"));
+
+    {
+      ManagedSnapshot s3(db_);
+      ASSERT_EQ(3U, GetNumSnapshots());
+      ASSERT_EQ(time_snap1, GetTimeOldestSnapshots());
+      ASSERT_EQ(GetSequenceOldestSnapshots(), s1->GetSequenceNumber());
+
+      ASSERT_OK(Put(0, "foo", "0v4"));
+      ASSERT_OK(Put(1, "foo", "1v4"));
+      ASSERT_EQ("0v1", Get(0, "foo", s1));
+      ASSERT_EQ("1v1", Get(1, "foo", s1));
+      ASSERT_EQ("0v2", Get(0, "foo", s2));
+      ASSERT_EQ("1v2", Get(1, "foo", s2));
+      ASSERT_EQ("0v3", Get(0, "foo", s3.snapshot()));
+      ASSERT_EQ("1v3", Get(1, "foo", s3.snapshot()));
+      ASSERT_EQ("0v4", Get(0, "foo"));
+      ASSERT_EQ("1v4", Get(1, "foo"));
+    }
+
+    ASSERT_EQ(2U, GetNumSnapshots());
+    ASSERT_EQ(time_snap1, GetTimeOldestSnapshots());
+    ASSERT_EQ(GetSequenceOldestSnapshots(), s1->GetSequenceNumber());
+    ASSERT_EQ("0v1", Get(0, "foo", s1));
+    ASSERT_EQ("1v1", Get(1, "foo", s1));
+    ASSERT_EQ("0v2", Get(0, "foo", s2));
+    ASSERT_EQ("1v2", Get(1, "foo", s2));
+    ASSERT_EQ("0v4", Get(0, "foo"));
+    ASSERT_EQ("1v4", Get(1, "foo"));
+
+    db_->ReleaseSnapshot(s1);
+    ASSERT_EQ("0v2", Get(0, "foo", s2));
+    ASSERT_EQ("1v2", Get(1, "foo", s2));
+    ASSERT_EQ("0v4", Get(0, "foo"));
+    ASSERT_EQ("1v4", Get(1, "foo"));
+    ASSERT_EQ(1U, GetNumSnapshots());
+    ASSERT_LT(time_snap1, GetTimeOldestSnapshots());
+    ASSERT_EQ(GetSequenceOldestSnapshots(), s2->GetSequenceNumber());
+
+    db_->ReleaseSnapshot(s2);
+    ASSERT_EQ(0U, GetNumSnapshots());
+    ASSERT_EQ(GetSequenceOldestSnapshots(), 0);
+    ASSERT_EQ("0v4", Get(0, "foo"));
+    ASSERT_EQ("1v4", Get(1, "foo"));
+  } while (ChangeOptions());
+}
+
+#endif  // ROCKSDB_LITE
+
+class DBBasicMultiConfigs : public DBBasicTest,
+                            public ::testing::WithParamInterface<int> {
+ public:
+  DBBasicMultiConfigs() { option_config_ = GetParam(); }
+
+  static std::vector<int> GenerateOptionConfigs() {
+    std::vector<int> option_configs;
+    for (int option_config = kDefault; option_config < kEnd; ++option_config) {
+      if (!ShouldSkipOptions(option_config, kSkipFIFOCompaction)) {
+        option_configs.push_back(option_config);
+      }
+    }
+    return option_configs;
+  }
+};
+
+TEST_P(DBBasicMultiConfigs, CompactBetweenSnapshots) {
+  anon::OptionsOverride options_override;
+  options_override.skip_policy = kSkipNoSnapshot;
+  Options options = CurrentOptions(options_override);
+  options.disable_auto_compactions = true;
+  DestroyAndReopen(options);
+  CreateAndReopenWithCF({"pikachu"}, options);
+  Random rnd(301);
+  FillLevels("a", "z", 1);
+
+  ASSERT_OK(Put(1, "foo", "first"));
+  const Snapshot* snapshot1 = db_->GetSnapshot();
+  ASSERT_OK(Put(1, "foo", "second"));
+  ASSERT_OK(Put(1, "foo", "third"));
+  ASSERT_OK(Put(1, "foo", "fourth"));
+  const Snapshot* snapshot2 = db_->GetSnapshot();
+  ASSERT_OK(Put(1, "foo", "fifth"));
+  ASSERT_OK(Put(1, "foo", "sixth"));
+
+  // All entries (including duplicates) exist
+  // before any compaction or flush is triggered.
+  ASSERT_EQ(AllEntriesFor("foo", 1),
+            "[ sixth, fifth, fourth, third, second, first ]");
+  ASSERT_EQ("sixth", Get(1, "foo"));
+  ASSERT_EQ("fourth", Get(1, "foo", snapshot2));
+  ASSERT_EQ("first", Get(1, "foo", snapshot1));
+
+  // After a flush, "second", "third" and "fifth" should
+  // be removed
+  ASSERT_OK(Flush(1));
+  ASSERT_EQ(AllEntriesFor("foo", 1), "[ sixth, fourth, first ]");
+
+  // after we release the snapshot1, only two values left
+  db_->ReleaseSnapshot(snapshot1);
+  FillLevels("a", "z", 1);
+  ASSERT_OK(dbfull()->CompactRange(CompactRangeOptions(), handles_[1], nullptr,
+                                   nullptr));
+
+  // We have only one valid snapshot snapshot2. Since snapshot1 is
+  // not valid anymore, "first" should be removed by a compaction.
+  ASSERT_EQ("sixth", Get(1, "foo"));
+  ASSERT_EQ("fourth", Get(1, "foo", snapshot2));
+  ASSERT_EQ(AllEntriesFor("foo", 1), "[ sixth, fourth ]");
+
+  // after we release the snapshot2, only one value should be left
+  db_->ReleaseSnapshot(snapshot2);
+  FillLevels("a", "z", 1);
+  ASSERT_OK(dbfull()->CompactRange(CompactRangeOptions(), handles_[1], nullptr,
+                                   nullptr));
+  ASSERT_EQ("sixth", Get(1, "foo"));
+  ASSERT_EQ(AllEntriesFor("foo", 1), "[ sixth ]");
+}
+
+INSTANTIATE_TEST_CASE_P(
+    DBBasicMultiConfigs, DBBasicMultiConfigs,
+    ::testing::ValuesIn(DBBasicMultiConfigs::GenerateOptionConfigs()));
+
+TEST_F(DBBasicTest, DBOpen_Options) {
+  Options options = CurrentOptions();
+  Close();
+  Destroy(options);
+
+  // Does not exist, and create_if_missing == false: error
+  DB* db = nullptr;
+  options.create_if_missing = false;
+  Status s = DB::Open(options, dbname_, &db);
+  ASSERT_TRUE(strstr(s.ToString().c_str(), "does not exist") != nullptr);
+  ASSERT_TRUE(db == nullptr);
+
+  // Does not exist, and create_if_missing == true: OK
+  options.create_if_missing = true;
+  s = DB::Open(options, dbname_, &db);
+  ASSERT_OK(s);
+  ASSERT_TRUE(db != nullptr);
+
+  delete db;
+  db = nullptr;
+
+  // Does exist, and error_if_exists == true: error
+  options.create_if_missing = false;
+  options.error_if_exists = true;
+  s = DB::Open(options, dbname_, &db);
+  ASSERT_TRUE(strstr(s.ToString().c_str(), "exists") != nullptr);
+  ASSERT_TRUE(db == nullptr);
+
+  // Does exist, and error_if_exists == false: OK
+  options.create_if_missing = true;
+  options.error_if_exists = false;
+  s = DB::Open(options, dbname_, &db);
+  ASSERT_OK(s);
+  ASSERT_TRUE(db != nullptr);
+
+  delete db;
+  db = nullptr;
+}
+
+TEST_F(DBBasicTest, CompactOnFlush) {
+  anon::OptionsOverride options_override;
+  options_override.skip_policy = kSkipNoSnapshot;
+  do {
+    Options options = CurrentOptions(options_override);
+    options.disable_auto_compactions = true;
+    CreateAndReopenWithCF({"pikachu"}, options);
+
+    ASSERT_OK(Put(1, "foo", "v1"));
+    ASSERT_OK(Flush(1));
+    ASSERT_EQ(AllEntriesFor("foo", 1), "[ v1 ]");
+
+    // Write two new keys
+    ASSERT_OK(Put(1, "a", "begin"));
+    ASSERT_OK(Put(1, "z", "end"));
+    ASSERT_OK(Flush(1));
+
+    // Case1: Delete followed by a put
+    ASSERT_OK(Delete(1, "foo"));
+    ASSERT_OK(Put(1, "foo", "v2"));
+    ASSERT_EQ(AllEntriesFor("foo", 1), "[ v2, DEL, v1 ]");
+
+    // After the current memtable is flushed, the DEL should
+    // have been removed
+    ASSERT_OK(Flush(1));
+    ASSERT_EQ(AllEntriesFor("foo", 1), "[ v2, v1 ]");
+
+    ASSERT_OK(dbfull()->CompactRange(CompactRangeOptions(), handles_[1],
+                                     nullptr, nullptr));
+    ASSERT_EQ(AllEntriesFor("foo", 1), "[ v2 ]");
+
+    // Case 2: Delete followed by another delete
+    ASSERT_OK(Delete(1, "foo"));
+    ASSERT_OK(Delete(1, "foo"));
+    ASSERT_EQ(AllEntriesFor("foo", 1), "[ DEL, DEL, v2 ]");
+    ASSERT_OK(Flush(1));
+    ASSERT_EQ(AllEntriesFor("foo", 1), "[ DEL, v2 ]");
+    ASSERT_OK(dbfull()->CompactRange(CompactRangeOptions(), handles_[1],
+                                     nullptr, nullptr));
+    ASSERT_EQ(AllEntriesFor("foo", 1), "[ ]");
+
+    // Case 3: Put followed by a delete
+    ASSERT_OK(Put(1, "foo", "v3"));
+    ASSERT_OK(Delete(1, "foo"));
+    ASSERT_EQ(AllEntriesFor("foo", 1), "[ DEL, v3 ]");
+    ASSERT_OK(Flush(1));
+    ASSERT_EQ(AllEntriesFor("foo", 1), "[ DEL ]");
+    ASSERT_OK(dbfull()->CompactRange(CompactRangeOptions(), handles_[1],
+                                     nullptr, nullptr));
+    ASSERT_EQ(AllEntriesFor("foo", 1), "[ ]");
+
+    // Case 4: Put followed by another Put
+    ASSERT_OK(Put(1, "foo", "v4"));
+    ASSERT_OK(Put(1, "foo", "v5"));
+    ASSERT_EQ(AllEntriesFor("foo", 1), "[ v5, v4 ]");
+    ASSERT_OK(Flush(1));
+    ASSERT_EQ(AllEntriesFor("foo", 1), "[ v5 ]");
+    ASSERT_OK(dbfull()->CompactRange(CompactRangeOptions(), handles_[1],
+                                     nullptr, nullptr));
+    ASSERT_EQ(AllEntriesFor("foo", 1), "[ v5 ]");
+
+    // clear database
+    ASSERT_OK(Delete(1, "foo"));
+    ASSERT_OK(dbfull()->CompactRange(CompactRangeOptions(), handles_[1],
+                                     nullptr, nullptr));
+    ASSERT_EQ(AllEntriesFor("foo", 1), "[ ]");
+
+    // Case 5: Put followed by snapshot followed by another Put
+    // Both puts should remain.
+    ASSERT_OK(Put(1, "foo", "v6"));
+    const Snapshot* snapshot = db_->GetSnapshot();
+    ASSERT_OK(Put(1, "foo", "v7"));
+    ASSERT_OK(Flush(1));
+    ASSERT_EQ(AllEntriesFor("foo", 1), "[ v7, v6 ]");
+    db_->ReleaseSnapshot(snapshot);
+
+    // clear database
+    ASSERT_OK(Delete(1, "foo"));
+    ASSERT_OK(dbfull()->CompactRange(CompactRangeOptions(), handles_[1],
+                                     nullptr, nullptr));
+    ASSERT_EQ(AllEntriesFor("foo", 1), "[ ]");
+
+    // Case 5: snapshot followed by a put followed by another Put
+    // Only the last put should remain.
+    const Snapshot* snapshot1 = db_->GetSnapshot();
+    ASSERT_OK(Put(1, "foo", "v8"));
+    ASSERT_OK(Put(1, "foo", "v9"));
+    ASSERT_OK(Flush(1));
+    ASSERT_EQ(AllEntriesFor("foo", 1), "[ v9 ]");
+    db_->ReleaseSnapshot(snapshot1);
+  } while (ChangeCompactOptions());
+}
+
+TEST_F(DBBasicTest, FlushOneColumnFamily) {
+  Options options = CurrentOptions();
+  CreateAndReopenWithCF({"pikachu", "ilya", "muromec", "dobrynia", "nikitich",
+                         "alyosha", "popovich"},
+                        options);
+
+  ASSERT_OK(Put(0, "Default", "Default"));
+  ASSERT_OK(Put(1, "pikachu", "pikachu"));
+  ASSERT_OK(Put(2, "ilya", "ilya"));
+  ASSERT_OK(Put(3, "muromec", "muromec"));
+  ASSERT_OK(Put(4, "dobrynia", "dobrynia"));
+  ASSERT_OK(Put(5, "nikitich", "nikitich"));
+  ASSERT_OK(Put(6, "alyosha", "alyosha"));
+  ASSERT_OK(Put(7, "popovich", "popovich"));
+
+  for (int i = 0; i < 8; ++i) {
+    ASSERT_OK(Flush(i));
+    auto tables = ListTableFiles(env_, dbname_);
+    ASSERT_EQ(tables.size(), i + 1U);
+  }
+}
+
+TEST_F(DBBasicTest, MultiGetSimple) {
+  do {
+    CreateAndReopenWithCF({"pikachu"}, CurrentOptions());
+    SetPerfLevel(kEnableCount);
+    ASSERT_OK(Put(1, "k1", "v1"));
+    ASSERT_OK(Put(1, "k2", "v2"));
+    ASSERT_OK(Put(1, "k3", "v3"));
+    ASSERT_OK(Put(1, "k4", "v4"));
+    ASSERT_OK(Delete(1, "k4"));
+    ASSERT_OK(Put(1, "k5", "v5"));
+    ASSERT_OK(Delete(1, "no_key"));
+
+    std::vector<Slice> keys({"k1", "k2", "k3", "k4", "k5", "no_key"});
+
+    std::vector<std::string> values(20, "Temporary data to be overwritten");
+    std::vector<ColumnFamilyHandle*> cfs(keys.size(), handles_[1]);
+
+    get_perf_context()->Reset();
+    std::vector<Status> s = db_->MultiGet(ReadOptions(), cfs, keys, &values);
+    ASSERT_EQ(values.size(), keys.size());
+    ASSERT_EQ(values[0], "v1");
+    ASSERT_EQ(values[1], "v2");
+    ASSERT_EQ(values[2], "v3");
+    ASSERT_EQ(values[4], "v5");
+    // four kv pairs * two bytes per value
+    ASSERT_EQ(8, (int)get_perf_context()->multiget_read_bytes);
+
+    ASSERT_OK(s[0]);
+    ASSERT_OK(s[1]);
+    ASSERT_OK(s[2]);
+    ASSERT_TRUE(s[3].IsNotFound());
+    ASSERT_OK(s[4]);
+    ASSERT_TRUE(s[5].IsNotFound());
+    SetPerfLevel(kDisable);
+  } while (ChangeCompactOptions());
+}
+
+TEST_F(DBBasicTest, MultiGetEmpty) {
+  do {
+    CreateAndReopenWithCF({"pikachu"}, CurrentOptions());
+    // Empty Key Set
+    std::vector<Slice> keys;
+    std::vector<std::string> values;
+    std::vector<ColumnFamilyHandle*> cfs;
+    std::vector<Status> s = db_->MultiGet(ReadOptions(), cfs, keys, &values);
+    ASSERT_EQ(s.size(), 0U);
+
+    // Empty Database, Empty Key Set
+    Options options = CurrentOptions();
+    options.create_if_missing = true;
+    DestroyAndReopen(options);
+    CreateAndReopenWithCF({"pikachu"}, options);
+    s = db_->MultiGet(ReadOptions(), cfs, keys, &values);
+    ASSERT_EQ(s.size(), 0U);
+
+    // Empty Database, Search for Keys
+    keys.resize(2);
+    keys[0] = "a";
+    keys[1] = "b";
+    cfs.push_back(handles_[0]);
+    cfs.push_back(handles_[1]);
+    s = db_->MultiGet(ReadOptions(), cfs, keys, &values);
+    ASSERT_EQ(static_cast<int>(s.size()), 2);
+    ASSERT_TRUE(s[0].IsNotFound() && s[1].IsNotFound());
+  } while (ChangeCompactOptions());
+}
+
+class DBBlockChecksumTest : public DBBasicTest,
+                            public testing::WithParamInterface<uint32_t> {};
+
+INSTANTIATE_TEST_CASE_P(FormatVersions, DBBlockChecksumTest,
+                        testing::ValuesIn(test::kFooterFormatVersionsToTest));
+
+TEST_P(DBBlockChecksumTest, BlockChecksumTest) {
+  BlockBasedTableOptions table_options;
+  table_options.format_version = GetParam();
+  Options options = CurrentOptions();
+  const int kNumPerFile = 2;
+
+  const auto algs = GetSupportedChecksums();
+  const int algs_size = static_cast<int>(algs.size());
+
+  // generate one table with each type of checksum
+  for (int i = 0; i < algs_size; ++i) {
+    table_options.checksum = algs[i];
+    options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+    Reopen(options);
+    for (int j = 0; j < kNumPerFile; ++j) {
+      ASSERT_OK(Put(Key(i * kNumPerFile + j), Key(i * kNumPerFile + j)));
+    }
+    ASSERT_OK(Flush());
+  }
+
+  // with each valid checksum type setting...
+  for (int i = 0; i < algs_size; ++i) {
+    table_options.checksum = algs[i];
+    options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+    Reopen(options);
+    // verify every type of checksum (should be regardless of that setting)
+    for (int j = 0; j < algs_size * kNumPerFile; ++j) {
+      ASSERT_EQ(Key(j), Get(Key(j)));
+    }
+  }
+
+  // Now test invalid checksum type
+  table_options.checksum = static_cast<ChecksumType>(123);
+  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+  ASSERT_TRUE(TryReopen(options).IsInvalidArgument());
+}
+
+// On Windows you can have either memory mapped file or a file
+// with unbuffered access. So this asserts and does not make
+// sense to run
+#ifndef OS_WIN
+TEST_F(DBBasicTest, MmapAndBufferOptions) {
+  if (!IsMemoryMappedAccessSupported()) {
+    return;
+  }
+  Options options = CurrentOptions();
+
+  options.use_direct_reads = true;
+  options.allow_mmap_reads = true;
+  ASSERT_NOK(TryReopen(options));
+
+  // All other combinations are acceptable
+  options.use_direct_reads = false;
+  ASSERT_OK(TryReopen(options));
+
+  if (IsDirectIOSupported()) {
+    options.use_direct_reads = true;
+    options.allow_mmap_reads = false;
+    ASSERT_OK(TryReopen(options));
+  }
+
+  options.use_direct_reads = false;
+  ASSERT_OK(TryReopen(options));
+}
+#endif
+
+class TestEnv : public EnvWrapper {
+ public:
+  explicit TestEnv(Env* base_env) : EnvWrapper(base_env), close_count(0) {}
+  static const char* kClassName() { return "TestEnv"; }
+  const char* Name() const override { return kClassName(); }
+
+  class TestLogger : public Logger {
+   public:
+    using Logger::Logv;
+    explicit TestLogger(TestEnv* env_ptr) : Logger() { env = env_ptr; }
+    ~TestLogger() override {
+      if (!closed_) {
+        CloseHelper().PermitUncheckedError();
+      }
+    }
+    void Logv(const char* /*format*/, va_list /*ap*/) override {}
+
+   protected:
+    Status CloseImpl() override { return CloseHelper(); }
+
+   private:
+    Status CloseHelper() {
+      env->CloseCountInc();
+      ;
+      return Status::IOError();
+    }
+    TestEnv* env;
+  };
+
+  void CloseCountInc() { close_count++; }
+
+  int GetCloseCount() { return close_count; }
+
+  Status NewLogger(const std::string& /*fname*/,
+                   std::shared_ptr<Logger>* result) override {
+    result->reset(new TestLogger(this));
+    return Status::OK();
+  }
+
+ private:
+  int close_count;
+};
+
+TEST_F(DBBasicTest, DBClose) {
+  Options options = GetDefaultOptions();
+  std::string dbname = test::PerThreadDBPath("db_close_test");
+  ASSERT_OK(DestroyDB(dbname, options));
+
+  DB* db = nullptr;
+  TestEnv* env = new TestEnv(env_);
+  std::unique_ptr<TestEnv> local_env_guard(env);
+  options.create_if_missing = true;
+  options.env = env;
+  Status s = DB::Open(options, dbname, &db);
+  ASSERT_OK(s);
+  ASSERT_TRUE(db != nullptr);
+
+  s = db->Close();
+  ASSERT_EQ(env->GetCloseCount(), 1);
+  ASSERT_EQ(s, Status::IOError());
+
+  delete db;
+  ASSERT_EQ(env->GetCloseCount(), 1);
+
+  // Do not call DB::Close() and ensure our logger Close() still gets called
+  s = DB::Open(options, dbname, &db);
+  ASSERT_OK(s);
+  ASSERT_TRUE(db != nullptr);
+  delete db;
+  ASSERT_EQ(env->GetCloseCount(), 2);
+
+  // Provide our own logger and ensure DB::Close() does not close it
+  options.info_log.reset(new TestEnv::TestLogger(env));
+  options.create_if_missing = false;
+  s = DB::Open(options, dbname, &db);
+  ASSERT_OK(s);
+  ASSERT_TRUE(db != nullptr);
+
+  s = db->Close();
+  ASSERT_EQ(s, Status::OK());
+  delete db;
+  ASSERT_EQ(env->GetCloseCount(), 2);
+  options.info_log.reset();
+  ASSERT_EQ(env->GetCloseCount(), 3);
+}
+
+TEST_F(DBBasicTest, DBCloseAllDirectoryFDs) {
+  Options options = GetDefaultOptions();
+  std::string dbname = test::PerThreadDBPath("db_close_all_dir_fds_test");
+  // Configure a specific WAL directory
+  options.wal_dir = dbname + "_wal_dir";
+  // Configure 3 different data directories
+  options.db_paths.emplace_back(dbname + "_1", 512 * 1024);
+  options.db_paths.emplace_back(dbname + "_2", 4 * 1024 * 1024);
+  options.db_paths.emplace_back(dbname + "_3", 1024 * 1024 * 1024);
+
+  ASSERT_OK(DestroyDB(dbname, options));
+
+  DB* db = nullptr;
+  std::unique_ptr<Env> env = NewCompositeEnv(
+      std::make_shared<CountedFileSystem>(FileSystem::Default()));
+  options.create_if_missing = true;
+  options.env = env.get();
+  Status s = DB::Open(options, dbname, &db);
+  ASSERT_OK(s);
+  ASSERT_TRUE(db != nullptr);
+
+  // Explicitly close the database to ensure the open and close counter for
+  // directories are equivalent
+  s = db->Close();
+  auto* counted_fs =
+      options.env->GetFileSystem()->CheckedCast<CountedFileSystem>();
+  ASSERT_TRUE(counted_fs != nullptr);
+  ASSERT_EQ(counted_fs->counters()->dir_opens,
+            counted_fs->counters()->dir_closes);
+  ASSERT_OK(s);
+  delete db;
+}
+
+TEST_F(DBBasicTest, DBCloseFlushError) {
+  std::unique_ptr<FaultInjectionTestEnv> fault_injection_env(
+      new FaultInjectionTestEnv(env_));
+  Options options = GetDefaultOptions();
+  options.create_if_missing = true;
+  options.manual_wal_flush = true;
+  options.write_buffer_size = 100;
+  options.env = fault_injection_env.get();
+
+  Reopen(options);
+  ASSERT_OK(Put("key1", "value1"));
+  ASSERT_OK(Put("key2", "value2"));
+  ASSERT_OK(dbfull()->TEST_SwitchMemtable());
+  ASSERT_OK(Put("key3", "value3"));
+  fault_injection_env->SetFilesystemActive(false);
+  Status s = dbfull()->Close();
+  ASSERT_NE(s, Status::OK());
+  // retry should return the same error
+  s = dbfull()->Close();
+  ASSERT_NE(s, Status::OK());
+  fault_injection_env->SetFilesystemActive(true);
+  // retry close() is no-op even the system is back. Could be improved if
+  // Close() is retry-able: #9029
+  s = dbfull()->Close();
+  ASSERT_NE(s, Status::OK());
+  Destroy(options);
+}
+
+class DBMultiGetTestWithParam
+    : public DBBasicTest,
+      public testing::WithParamInterface<std::tuple<bool, bool>> {};
+
+TEST_P(DBMultiGetTestWithParam, MultiGetMultiCF) {
+#ifndef USE_COROUTINES
+  if (std::get<1>(GetParam())) {
+    ROCKSDB_GTEST_SKIP("This test requires coroutine support");
+    return;
+  }
+#endif  // USE_COROUTINES
+  Options options = CurrentOptions();
+  CreateAndReopenWithCF({"pikachu", "ilya", "muromec", "dobrynia", "nikitich",
+                         "alyosha", "popovich"},
+                        options);
+  // <CF, key, value> tuples
+  std::vector<std::tuple<int, std::string, std::string>> cf_kv_vec;
+  static const int num_keys = 24;
+  cf_kv_vec.reserve(num_keys);
+
+  for (int i = 0; i < num_keys; ++i) {
+    int cf = i / 3;
+    int cf_key = 1 % 3;
+    cf_kv_vec.emplace_back(std::make_tuple(
+        cf, "cf" + std::to_string(cf) + "_key_" + std::to_string(cf_key),
+        "cf" + std::to_string(cf) + "_val_" + std::to_string(cf_key)));
+    ASSERT_OK(Put(std::get<0>(cf_kv_vec[i]), std::get<1>(cf_kv_vec[i]),
+                  std::get<2>(cf_kv_vec[i])));
+  }
+
+  int get_sv_count = 0;
+  ROCKSDB_NAMESPACE::DBImpl* db = static_cast_with_check<DBImpl>(db_);
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "DBImpl::MultiGet::AfterRefSV", [&](void* /*arg*/) {
+        if (++get_sv_count == 2) {
+          // After MultiGet refs a couple of CFs, flush all CFs so MultiGet
+          // is forced to repeat the process
+          for (int i = 0; i < num_keys; ++i) {
+            int cf = i / 3;
+            int cf_key = i % 8;
+            if (cf_key == 0) {
+              ASSERT_OK(Flush(cf));
+            }
+            ASSERT_OK(Put(std::get<0>(cf_kv_vec[i]), std::get<1>(cf_kv_vec[i]),
+                          std::get<2>(cf_kv_vec[i]) + "_2"));
+          }
+        }
+        if (get_sv_count == 11) {
+          for (int i = 0; i < 8; ++i) {
+            auto* cfd = static_cast_with_check<ColumnFamilyHandleImpl>(
+                            db->GetColumnFamilyHandle(i))
+                            ->cfd();
+            ASSERT_EQ(cfd->TEST_GetLocalSV()->Get(), SuperVersion::kSVInUse);
+          }
+        }
+      });
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
+
+  std::vector<int> cfs;
+  std::vector<std::string> keys;
+  std::vector<std::string> values;
+
+  for (int i = 0; i < num_keys; ++i) {
+    cfs.push_back(std::get<0>(cf_kv_vec[i]));
+    keys.push_back(std::get<1>(cf_kv_vec[i]));
+  }
+
+  values = MultiGet(cfs, keys, nullptr, std::get<0>(GetParam()),
+                    std::get<1>(GetParam()));
+  ASSERT_EQ(values.size(), num_keys);
+  for (unsigned int j = 0; j < values.size(); ++j) {
+    ASSERT_EQ(values[j], std::get<2>(cf_kv_vec[j]) + "_2");
+  }
+
+  keys.clear();
+  cfs.clear();
+  cfs.push_back(std::get<0>(cf_kv_vec[0]));
+  keys.push_back(std::get<1>(cf_kv_vec[0]));
+  cfs.push_back(std::get<0>(cf_kv_vec[3]));
+  keys.push_back(std::get<1>(cf_kv_vec[3]));
+  cfs.push_back(std::get<0>(cf_kv_vec[4]));
+  keys.push_back(std::get<1>(cf_kv_vec[4]));
+  values = MultiGet(cfs, keys, nullptr, std::get<0>(GetParam()),
+                    std::get<1>(GetParam()));
+  ASSERT_EQ(values[0], std::get<2>(cf_kv_vec[0]) + "_2");
+  ASSERT_EQ(values[1], std::get<2>(cf_kv_vec[3]) + "_2");
+  ASSERT_EQ(values[2], std::get<2>(cf_kv_vec[4]) + "_2");
+
+  keys.clear();
+  cfs.clear();
+  cfs.push_back(std::get<0>(cf_kv_vec[7]));
+  keys.push_back(std::get<1>(cf_kv_vec[7]));
+  cfs.push_back(std::get<0>(cf_kv_vec[6]));
+  keys.push_back(std::get<1>(cf_kv_vec[6]));
+  cfs.push_back(std::get<0>(cf_kv_vec[1]));
+  keys.push_back(std::get<1>(cf_kv_vec[1]));
+  values = MultiGet(cfs, keys, nullptr, std::get<0>(GetParam()),
+                    std::get<1>(GetParam()));
+  ASSERT_EQ(values[0], std::get<2>(cf_kv_vec[7]) + "_2");
+  ASSERT_EQ(values[1], std::get<2>(cf_kv_vec[6]) + "_2");
+  ASSERT_EQ(values[2], std::get<2>(cf_kv_vec[1]) + "_2");
+
+  for (int cf = 0; cf < 8; ++cf) {
+    auto* cfd =
+        static_cast_with_check<ColumnFamilyHandleImpl>(
+            static_cast_with_check<DBImpl>(db_)->GetColumnFamilyHandle(cf))
+            ->cfd();
+    ASSERT_NE(cfd->TEST_GetLocalSV()->Get(), SuperVersion::kSVInUse);
+    ASSERT_NE(cfd->TEST_GetLocalSV()->Get(), SuperVersion::kSVObsolete);
+  }
+}
+
+TEST_P(DBMultiGetTestWithParam, MultiGetMultiCFMutex) {
+#ifndef USE_COROUTINES
+  if (std::get<1>(GetParam())) {
+    ROCKSDB_GTEST_SKIP("This test requires coroutine support");
+    return;
+  }
+#endif  // USE_COROUTINES
+  Options options = CurrentOptions();
+  CreateAndReopenWithCF({"pikachu", "ilya", "muromec", "dobrynia", "nikitich",
+                         "alyosha", "popovich"},
+                        options);
+
+  for (int i = 0; i < 8; ++i) {
+    ASSERT_OK(Put(i, "cf" + std::to_string(i) + "_key",
+                  "cf" + std::to_string(i) + "_val"));
+  }
+
+  int get_sv_count = 0;
+  int retries = 0;
+  bool last_try = false;
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "DBImpl::MultiGet::LastTry", [&](void* /*arg*/) {
+        last_try = true;
+        ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
+      });
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "DBImpl::MultiGet::AfterRefSV", [&](void* /*arg*/) {
+        if (last_try) {
+          return;
+        }
+        if (++get_sv_count == 2) {
+          ++retries;
+          get_sv_count = 0;
+          for (int i = 0; i < 8; ++i) {
+            ASSERT_OK(Flush(i));
+            ASSERT_OK(Put(
+                i, "cf" + std::to_string(i) + "_key",
+                "cf" + std::to_string(i) + "_val" + std::to_string(retries)));
+          }
+        }
+      });
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
+
+  std::vector<int> cfs;
+  std::vector<std::string> keys;
+  std::vector<std::string> values;
+
+  for (int i = 0; i < 8; ++i) {
+    cfs.push_back(i);
+    keys.push_back("cf" + std::to_string(i) + "_key");
+  }
+
+  values = MultiGet(cfs, keys, nullptr, std::get<0>(GetParam()),
+                    std::get<1>(GetParam()));
+  ASSERT_TRUE(last_try);
+  ASSERT_EQ(values.size(), 8);
+  for (unsigned int j = 0; j < values.size(); ++j) {
+    ASSERT_EQ(values[j],
+              "cf" + std::to_string(j) + "_val" + std::to_string(retries));
+  }
+  for (int i = 0; i < 8; ++i) {
+    auto* cfd =
+        static_cast_with_check<ColumnFamilyHandleImpl>(
+            static_cast_with_check<DBImpl>(db_)->GetColumnFamilyHandle(i))
+            ->cfd();
+    ASSERT_NE(cfd->TEST_GetLocalSV()->Get(), SuperVersion::kSVInUse);
+  }
+}
+
+TEST_P(DBMultiGetTestWithParam, MultiGetMultiCFSnapshot) {
+#ifndef USE_COROUTINES
+  if (std::get<1>(GetParam())) {
+    ROCKSDB_GTEST_SKIP("This test requires coroutine support");
+    return;
+  }
+#endif  // USE_COROUTINES
+  Options options = CurrentOptions();
+  CreateAndReopenWithCF({"pikachu", "ilya", "muromec", "dobrynia", "nikitich",
+                         "alyosha", "popovich"},
+                        options);
+
+  for (int i = 0; i < 8; ++i) {
+    ASSERT_OK(Put(i, "cf" + std::to_string(i) + "_key",
+                  "cf" + std::to_string(i) + "_val"));
+  }
+
+  int get_sv_count = 0;
+  ROCKSDB_NAMESPACE::DBImpl* db = static_cast_with_check<DBImpl>(db_);
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "DBImpl::MultiGet::AfterRefSV", [&](void* /*arg*/) {
+        if (++get_sv_count == 2) {
+          for (int i = 0; i < 8; ++i) {
+            ASSERT_OK(Flush(i));
+            ASSERT_OK(Put(i, "cf" + std::to_string(i) + "_key",
+                          "cf" + std::to_string(i) + "_val2"));
+          }
+        }
+        if (get_sv_count == 8) {
+          for (int i = 0; i < 8; ++i) {
+            auto* cfd = static_cast_with_check<ColumnFamilyHandleImpl>(
+                            db->GetColumnFamilyHandle(i))
+                            ->cfd();
+            ASSERT_TRUE(
+                (cfd->TEST_GetLocalSV()->Get() == SuperVersion::kSVInUse) ||
+                (cfd->TEST_GetLocalSV()->Get() == SuperVersion::kSVObsolete));
+          }
+        }
+      });
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
+
+  std::vector<int> cfs;
+  std::vector<std::string> keys;
+  std::vector<std::string> values;
+
+  for (int i = 0; i < 8; ++i) {
+    cfs.push_back(i);
+    keys.push_back("cf" + std::to_string(i) + "_key");
+  }
+
+  const Snapshot* snapshot = db_->GetSnapshot();
+  values = MultiGet(cfs, keys, snapshot, std::get<0>(GetParam()),
+                    std::get<1>(GetParam()));
+  db_->ReleaseSnapshot(snapshot);
+  ASSERT_EQ(values.size(), 8);
+  for (unsigned int j = 0; j < values.size(); ++j) {
+    ASSERT_EQ(values[j], "cf" + std::to_string(j) + "_val");
+  }
+  for (int i = 0; i < 8; ++i) {
+    auto* cfd =
+        static_cast_with_check<ColumnFamilyHandleImpl>(
+            static_cast_with_check<DBImpl>(db_)->GetColumnFamilyHandle(i))
+            ->cfd();
+    ASSERT_NE(cfd->TEST_GetLocalSV()->Get(), SuperVersion::kSVInUse);
+  }
+}
+
+TEST_P(DBMultiGetTestWithParam, MultiGetMultiCFUnsorted) {
+#ifndef USE_COROUTINES
+  if (std::get<1>(GetParam())) {
+    ROCKSDB_GTEST_SKIP("This test requires coroutine support");
+    return;
+  }
+#endif  // USE_COROUTINES
+  Options options = CurrentOptions();
+  CreateAndReopenWithCF({"one", "two"}, options);
+
+  ASSERT_OK(Put(1, "foo", "bar"));
+  ASSERT_OK(Put(2, "baz", "xyz"));
+  ASSERT_OK(Put(1, "abc", "def"));
+
+  // Note: keys for the same CF do not form a consecutive range
+  std::vector<int> cfs{1, 2, 1};
+  std::vector<std::string> keys{"foo", "baz", "abc"};
+  std::vector<std::string> values;
+
+  values = MultiGet(cfs, keys, /* snapshot */ nullptr,
+                    /* batched */ std::get<0>(GetParam()),
+                    /* async */ std::get<1>(GetParam()));
+
+  ASSERT_EQ(values.size(), 3);
+  ASSERT_EQ(values[0], "bar");
+  ASSERT_EQ(values[1], "xyz");
+  ASSERT_EQ(values[2], "def");
+}
+
+TEST_P(DBMultiGetTestWithParam, MultiGetBatchedSimpleUnsorted) {
+#ifndef USE_COROUTINES
+  if (std::get<1>(GetParam())) {
+    ROCKSDB_GTEST_SKIP("This test requires coroutine support");
+    return;
+  }
+#endif  // USE_COROUTINES
+  // Skip for unbatched MultiGet
+  if (!std::get<0>(GetParam())) {
+    ROCKSDB_GTEST_BYPASS("This test is only for batched MultiGet");
+    return;
+  }
+  do {
+    CreateAndReopenWithCF({"pikachu"}, CurrentOptions());
+    SetPerfLevel(kEnableCount);
+    ASSERT_OK(Put(1, "k1", "v1"));
+    ASSERT_OK(Put(1, "k2", "v2"));
+    ASSERT_OK(Put(1, "k3", "v3"));
+    ASSERT_OK(Put(1, "k4", "v4"));
+    ASSERT_OK(Delete(1, "k4"));
+    ASSERT_OK(Put(1, "k5", "v5"));
+    ASSERT_OK(Delete(1, "no_key"));
+
+    get_perf_context()->Reset();
+
+    std::vector<Slice> keys({"no_key", "k5", "k4", "k3", "k2", "k1"});
+    std::vector<PinnableSlice> values(keys.size());
+    std::vector<ColumnFamilyHandle*> cfs(keys.size(), handles_[1]);
+    std::vector<Status> s(keys.size());
+
+    ReadOptions ro;
+    ro.async_io = std::get<1>(GetParam());
+    db_->MultiGet(ro, handles_[1], keys.size(), keys.data(), values.data(),
+                  s.data(), false);
+
+    ASSERT_EQ(values.size(), keys.size());
+    ASSERT_EQ(std::string(values[5].data(), values[5].size()), "v1");
+    ASSERT_EQ(std::string(values[4].data(), values[4].size()), "v2");
+    ASSERT_EQ(std::string(values[3].data(), values[3].size()), "v3");
+    ASSERT_EQ(std::string(values[1].data(), values[1].size()), "v5");
+    // four kv pairs * two bytes per value
+    ASSERT_EQ(8, (int)get_perf_context()->multiget_read_bytes);
+
+    ASSERT_TRUE(s[0].IsNotFound());
+    ASSERT_OK(s[1]);
+    ASSERT_TRUE(s[2].IsNotFound());
+    ASSERT_OK(s[3]);
+    ASSERT_OK(s[4]);
+    ASSERT_OK(s[5]);
+
+    SetPerfLevel(kDisable);
+  } while (ChangeCompactOptions());
+}
+
+TEST_P(DBMultiGetTestWithParam, MultiGetBatchedSortedMultiFile) {
+#ifndef USE_COROUTINES
+  if (std::get<1>(GetParam())) {
+    ROCKSDB_GTEST_SKIP("This test requires coroutine support");
+    return;
+  }
+#endif  // USE_COROUTINES
+  // Skip for unbatched MultiGet
+  if (!std::get<0>(GetParam())) {
+    ROCKSDB_GTEST_BYPASS("This test is only for batched MultiGet");
+    return;
+  }
+  do {
+    CreateAndReopenWithCF({"pikachu"}, CurrentOptions());
+    SetPerfLevel(kEnableCount);
+    // To expand the power of this test, generate > 1 table file and
+    // mix with memtable
+    ASSERT_OK(Put(1, "k1", "v1"));
+    ASSERT_OK(Put(1, "k2", "v2"));
+    ASSERT_OK(Flush(1));
+    ASSERT_OK(Put(1, "k3", "v3"));
+    ASSERT_OK(Put(1, "k4", "v4"));
+    ASSERT_OK(Flush(1));
+    ASSERT_OK(Delete(1, "k4"));
+    ASSERT_OK(Put(1, "k5", "v5"));
+    ASSERT_OK(Delete(1, "no_key"));
+
+    get_perf_context()->Reset();
+
+    std::vector<Slice> keys({"k1", "k2", "k3", "k4", "k5", "no_key"});
+    std::vector<PinnableSlice> values(keys.size());
+    std::vector<ColumnFamilyHandle*> cfs(keys.size(), handles_[1]);
+    std::vector<Status> s(keys.size());
+
+    ReadOptions ro;
+    ro.async_io = std::get<1>(GetParam());
+    db_->MultiGet(ro, handles_[1], keys.size(), keys.data(), values.data(),
+                  s.data(), true);
+
+    ASSERT_EQ(values.size(), keys.size());
+    ASSERT_EQ(std::string(values[0].data(), values[0].size()), "v1");
+    ASSERT_EQ(std::string(values[1].data(), values[1].size()), "v2");
+    ASSERT_EQ(std::string(values[2].data(), values[2].size()), "v3");
+    ASSERT_EQ(std::string(values[4].data(), values[4].size()), "v5");
+    // four kv pairs * two bytes per value
+    ASSERT_EQ(8, (int)get_perf_context()->multiget_read_bytes);
+
+    ASSERT_OK(s[0]);
+    ASSERT_OK(s[1]);
+    ASSERT_OK(s[2]);
+    ASSERT_TRUE(s[3].IsNotFound());
+    ASSERT_OK(s[4]);
+    ASSERT_TRUE(s[5].IsNotFound());
+
+    SetPerfLevel(kDisable);
+  } while (ChangeOptions());
+}
+
+TEST_P(DBMultiGetTestWithParam, MultiGetBatchedDuplicateKeys) {
+#ifndef USE_COROUTINES
+  if (std::get<1>(GetParam())) {
+    ROCKSDB_GTEST_SKIP("This test requires coroutine support");
+    return;
+  }
+#endif  // USE_COROUTINES
+  // Skip for unbatched MultiGet
+  if (!std::get<0>(GetParam())) {
+    ROCKSDB_GTEST_BYPASS("This test is only for batched MultiGet");
+    return;
+  }
+  Options opts = CurrentOptions();
+  opts.merge_operator = MergeOperators::CreateStringAppendOperator();
+  CreateAndReopenWithCF({"pikachu"}, opts);
+  SetPerfLevel(kEnableCount);
+  // To expand the power of this test, generate > 1 table file and
+  // mix with memtable
+  ASSERT_OK(Merge(1, "k1", "v1"));
+  ASSERT_OK(Merge(1, "k2", "v2"));
+  ASSERT_OK(Flush(1));
+  MoveFilesToLevel(2, 1);
+  ASSERT_OK(Merge(1, "k3", "v3"));
+  ASSERT_OK(Merge(1, "k4", "v4"));
+  ASSERT_OK(Flush(1));
+  MoveFilesToLevel(2, 1);
+  ASSERT_OK(Merge(1, "k4", "v4_2"));
+  ASSERT_OK(Merge(1, "k6", "v6"));
+  ASSERT_OK(Flush(1));
+  MoveFilesToLevel(2, 1);
+  ASSERT_OK(Merge(1, "k7", "v7"));
+  ASSERT_OK(Merge(1, "k8", "v8"));
+  ASSERT_OK(Flush(1));
+  MoveFilesToLevel(2, 1);
+
+  get_perf_context()->Reset();
+
+  std::vector<Slice> keys({"k8", "k8", "k8", "k4", "k4", "k1", "k3"});
+  std::vector<PinnableSlice> values(keys.size());
+  std::vector<ColumnFamilyHandle*> cfs(keys.size(), handles_[1]);
+  std::vector<Status> s(keys.size());
+
+  ReadOptions ro;
+  ro.async_io = std::get<1>(GetParam());
+  db_->MultiGet(ro, handles_[1], keys.size(), keys.data(), values.data(),
+                s.data(), false);
+
+  ASSERT_EQ(values.size(), keys.size());
+  ASSERT_EQ(std::string(values[0].data(), values[0].size()), "v8");
+  ASSERT_EQ(std::string(values[1].data(), values[1].size()), "v8");
+  ASSERT_EQ(std::string(values[2].data(), values[2].size()), "v8");
+  ASSERT_EQ(std::string(values[3].data(), values[3].size()), "v4,v4_2");
+  ASSERT_EQ(std::string(values[4].data(), values[4].size()), "v4,v4_2");
+  ASSERT_EQ(std::string(values[5].data(), values[5].size()), "v1");
+  ASSERT_EQ(std::string(values[6].data(), values[6].size()), "v3");
+  ASSERT_EQ(24, (int)get_perf_context()->multiget_read_bytes);
+
+  for (Status& status : s) {
+    ASSERT_OK(status);
+  }
+
+  SetPerfLevel(kDisable);
+}
+
+TEST_P(DBMultiGetTestWithParam, MultiGetBatchedMultiLevel) {
+#ifndef USE_COROUTINES
+  if (std::get<1>(GetParam())) {
+    ROCKSDB_GTEST_SKIP("This test requires coroutine support");
+    return;
+  }
+#endif  // USE_COROUTINES
+  // Skip for unbatched MultiGet
+  if (!std::get<0>(GetParam())) {
+    ROCKSDB_GTEST_BYPASS("This test is only for batched MultiGet");
+    return;
+  }
+  Options options = CurrentOptions();
+  options.disable_auto_compactions = true;
+  Reopen(options);
+  int num_keys = 0;
+
+  for (int i = 0; i < 128; ++i) {
+    ASSERT_OK(Put("key_" + std::to_string(i), "val_l2_" + std::to_string(i)));
+    num_keys++;
+    if (num_keys == 8) {
+      ASSERT_OK(Flush());
+      num_keys = 0;
+    }
+  }
+  if (num_keys > 0) {
+    ASSERT_OK(Flush());
+    num_keys = 0;
+  }
+  MoveFilesToLevel(2);
+
+  for (int i = 0; i < 128; i += 3) {
+    ASSERT_OK(Put("key_" + std::to_string(i), "val_l1_" + std::to_string(i)));
+    num_keys++;
+    if (num_keys == 8) {
+      ASSERT_OK(Flush());
+      num_keys = 0;
+    }
+  }
+  if (num_keys > 0) {
+    ASSERT_OK(Flush());
+    num_keys = 0;
+  }
+  MoveFilesToLevel(1);
+
+  for (int i = 0; i < 128; i += 5) {
+    ASSERT_OK(Put("key_" + std::to_string(i), "val_l0_" + std::to_string(i)));
+    num_keys++;
+    if (num_keys == 8) {
+      ASSERT_OK(Flush());
+      num_keys = 0;
+    }
+  }
+  if (num_keys > 0) {
+    ASSERT_OK(Flush());
+    num_keys = 0;
+  }
+  ASSERT_EQ(0, num_keys);
+
+  for (int i = 0; i < 128; i += 9) {
+    ASSERT_OK(Put("key_" + std::to_string(i), "val_mem_" + std::to_string(i)));
+  }
+
+  std::vector<std::string> keys;
+  std::vector<std::string> values;
+
+  for (int i = 64; i < 80; ++i) {
+    keys.push_back("key_" + std::to_string(i));
+  }
+
+  values = MultiGet(keys, nullptr, std::get<1>(GetParam()));
+  ASSERT_EQ(values.size(), 16);
+  for (unsigned int j = 0; j < values.size(); ++j) {
+    int key = j + 64;
+    if (key % 9 == 0) {
+      ASSERT_EQ(values[j], "val_mem_" + std::to_string(key));
+    } else if (key % 5 == 0) {
+      ASSERT_EQ(values[j], "val_l0_" + std::to_string(key));
+    } else if (key % 3 == 0) {
+      ASSERT_EQ(values[j], "val_l1_" + std::to_string(key));
+    } else {
+      ASSERT_EQ(values[j], "val_l2_" + std::to_string(key));
+    }
+  }
+}
+
+TEST_P(DBMultiGetTestWithParam, MultiGetBatchedMultiLevelMerge) {
+#ifndef USE_COROUTINES
+  if (std::get<1>(GetParam())) {
+    ROCKSDB_GTEST_SKIP("This test requires coroutine support");
+    return;
+  }
+#endif  // USE_COROUTINES
+  // Skip for unbatched MultiGet
+  if (!std::get<0>(GetParam())) {
+    ROCKSDB_GTEST_BYPASS("This test is only for batched MultiGet");
+    return;
+  }
+  Options options = CurrentOptions();
+  options.disable_auto_compactions = true;
+  options.merge_operator = MergeOperators::CreateStringAppendOperator();
+  BlockBasedTableOptions bbto;
+  bbto.filter_policy.reset(NewBloomFilterPolicy(10, false));
+  options.table_factory.reset(NewBlockBasedTableFactory(bbto));
+  Reopen(options);
+  int num_keys = 0;
+
+  for (int i = 0; i < 128; ++i) {
+    ASSERT_OK(Put("key_" + std::to_string(i), "val_l2_" + std::to_string(i)));
+    num_keys++;
+    if (num_keys == 8) {
+      ASSERT_OK(Flush());
+      num_keys = 0;
+    }
+  }
+  if (num_keys > 0) {
+    ASSERT_OK(Flush());
+    num_keys = 0;
+  }
+  MoveFilesToLevel(2);
+
+  for (int i = 0; i < 128; i += 3) {
+    ASSERT_OK(Merge("key_" + std::to_string(i), "val_l1_" + std::to_string(i)));
+    num_keys++;
+    if (num_keys == 8) {
+      ASSERT_OK(Flush());
+      num_keys = 0;
+    }
+  }
+  if (num_keys > 0) {
+    ASSERT_OK(Flush());
+    num_keys = 0;
+  }
+  MoveFilesToLevel(1);
+
+  for (int i = 0; i < 128; i += 5) {
+    ASSERT_OK(Merge("key_" + std::to_string(i), "val_l0_" + std::to_string(i)));
+    num_keys++;
+    if (num_keys == 8) {
+      ASSERT_OK(Flush());
+      num_keys = 0;
+    }
+  }
+  if (num_keys > 0) {
+    ASSERT_OK(Flush());
+    num_keys = 0;
+  }
+  ASSERT_EQ(0, num_keys);
+
+  for (int i = 0; i < 128; i += 9) {
+    ASSERT_OK(
+        Merge("key_" + std::to_string(i), "val_mem_" + std::to_string(i)));
+  }
+
+  std::vector<std::string> keys;
+  std::vector<std::string> values;
+
+  for (int i = 32; i < 80; ++i) {
+    keys.push_back("key_" + std::to_string(i));
+  }
+
+  values = MultiGet(keys, nullptr, std::get<1>(GetParam()));
+  ASSERT_EQ(values.size(), keys.size());
+  for (unsigned int j = 0; j < 48; ++j) {
+    int key = j + 32;
+    std::string value;
+    value.append("val_l2_" + std::to_string(key));
+    if (key % 3 == 0) {
+      value.append(",");
+      value.append("val_l1_" + std::to_string(key));
+    }
+    if (key % 5 == 0) {
+      value.append(",");
+      value.append("val_l0_" + std::to_string(key));
+    }
+    if (key % 9 == 0) {
+      value.append(",");
+      value.append("val_mem_" + std::to_string(key));
+    }
+    ASSERT_EQ(values[j], value);
+  }
+}
+
+TEST_P(DBMultiGetTestWithParam, MultiGetBatchedValueSizeInMemory) {
+#ifndef USE_COROUTINES
+  if (std::get<1>(GetParam())) {
+    ROCKSDB_GTEST_SKIP("This test requires coroutine support");
+    return;
+  }
+#endif  // USE_COROUTINES
+  // Skip for unbatched MultiGet
+  if (!std::get<0>(GetParam())) {
+    ROCKSDB_GTEST_BYPASS("This test is only for batched MultiGet");
+    return;
+  }
+  CreateAndReopenWithCF({"pikachu"}, CurrentOptions());
+  SetPerfLevel(kEnableCount);
+  ASSERT_OK(Put(1, "k1", "v_1"));
+  ASSERT_OK(Put(1, "k2", "v_2"));
+  ASSERT_OK(Put(1, "k3", "v_3"));
+  ASSERT_OK(Put(1, "k4", "v_4"));
+  ASSERT_OK(Put(1, "k5", "v_5"));
+  ASSERT_OK(Put(1, "k6", "v_6"));
+  std::vector<Slice> keys = {"k1", "k2", "k3", "k4", "k5", "k6"};
+  std::vector<PinnableSlice> values(keys.size());
+  std::vector<Status> s(keys.size());
+  std::vector<ColumnFamilyHandle*> cfs(keys.size(), handles_[1]);
+
+  get_perf_context()->Reset();
+  ReadOptions ro;
+  ro.value_size_soft_limit = 11;
+  ro.async_io = std::get<1>(GetParam());
+  db_->MultiGet(ro, handles_[1], keys.size(), keys.data(), values.data(),
+                s.data(), false);
+
+  ASSERT_EQ(values.size(), keys.size());
+  for (unsigned int i = 0; i < 4; i++) {
+    ASSERT_EQ(std::string(values[i].data(), values[i].size()),
+              "v_" + std::to_string(i + 1));
+  }
+
+  for (unsigned int i = 4; i < 6; i++) {
+    ASSERT_TRUE(s[i].IsAborted());
+  }
+
+  ASSERT_EQ(12, (int)get_perf_context()->multiget_read_bytes);
+  SetPerfLevel(kDisable);
+}
+
+TEST_P(DBMultiGetTestWithParam, MultiGetBatchedValueSize) {
+#ifndef USE_COROUTINES
+  if (std::get<1>(GetParam())) {
+    ROCKSDB_GTEST_SKIP("This test requires coroutine support");
+    return;
+  }
+#endif  // USE_COROUTINES
+  // Skip for unbatched MultiGet
+  if (!std::get<0>(GetParam())) {
+    return;
+  }
+  do {
+    CreateAndReopenWithCF({"pikachu"}, CurrentOptions());
+    SetPerfLevel(kEnableCount);
+
+    ASSERT_OK(Put(1, "k6", "v6"));
+    ASSERT_OK(Put(1, "k7", "v7_"));
+    ASSERT_OK(Put(1, "k3", "v3_"));
+    ASSERT_OK(Put(1, "k4", "v4"));
+    ASSERT_OK(Flush(1));
+    ASSERT_OK(Delete(1, "k4"));
+    ASSERT_OK(Put(1, "k11", "v11"));
+    ASSERT_OK(Delete(1, "no_key"));
+    ASSERT_OK(Put(1, "k8", "v8_"));
+    ASSERT_OK(Put(1, "k13", "v13"));
+    ASSERT_OK(Put(1, "k14", "v14"));
+    ASSERT_OK(Put(1, "k15", "v15"));
+    ASSERT_OK(Put(1, "k16", "v16"));
+    ASSERT_OK(Put(1, "k17", "v17"));
+    ASSERT_OK(Flush(1));
+
+    ASSERT_OK(Put(1, "k1", "v1_"));
+    ASSERT_OK(Put(1, "k2", "v2_"));
+    ASSERT_OK(Put(1, "k5", "v5_"));
+    ASSERT_OK(Put(1, "k9", "v9_"));
+    ASSERT_OK(Put(1, "k10", "v10"));
+    ASSERT_OK(Delete(1, "k2"));
+    ASSERT_OK(Delete(1, "k6"));
+
+    get_perf_context()->Reset();
+
+    std::vector<Slice> keys({"k1", "k10", "k11", "k12", "k13", "k14", "k15",
+                             "k16", "k17", "k2", "k3", "k4", "k5", "k6", "k7",
+                             "k8", "k9", "no_key"});
+    std::vector<PinnableSlice> values(keys.size());
+    std::vector<ColumnFamilyHandle*> cfs(keys.size(), handles_[1]);
+    std::vector<Status> s(keys.size());
+
+    ReadOptions ro;
+    ro.value_size_soft_limit = 20;
+    ro.async_io = std::get<1>(GetParam());
+    db_->MultiGet(ro, handles_[1], keys.size(), keys.data(), values.data(),
+                  s.data(), false);
+
+    ASSERT_EQ(values.size(), keys.size());
+
+    // In memory keys
+    ASSERT_EQ(std::string(values[0].data(), values[0].size()), "v1_");
+    ASSERT_EQ(std::string(values[1].data(), values[1].size()), "v10");
+    ASSERT_TRUE(s[9].IsNotFound());  // k2
+    ASSERT_EQ(std::string(values[12].data(), values[12].size()), "v5_");
+    ASSERT_TRUE(s[13].IsNotFound());  // k6
+    ASSERT_EQ(std::string(values[16].data(), values[16].size()), "v9_");
+
+    // In sst files
+    ASSERT_EQ(std::string(values[2].data(), values[1].size()), "v11");
+    ASSERT_EQ(std::string(values[4].data(), values[4].size()), "v13");
+    ASSERT_EQ(std::string(values[5].data(), values[5].size()), "v14");
+
+    // Remaining aborted after value_size exceeds.
+    ASSERT_TRUE(s[3].IsAborted());
+    ASSERT_TRUE(s[6].IsAborted());
+    ASSERT_TRUE(s[7].IsAborted());
+    ASSERT_TRUE(s[8].IsAborted());
+    ASSERT_TRUE(s[10].IsAborted());
+    ASSERT_TRUE(s[11].IsAborted());
+    ASSERT_TRUE(s[14].IsAborted());
+    ASSERT_TRUE(s[15].IsAborted());
+    ASSERT_TRUE(s[17].IsAborted());
+
+    // 6 kv pairs * 3 bytes per value (i.e. 18)
+    ASSERT_EQ(21, (int)get_perf_context()->multiget_read_bytes);
+    SetPerfLevel(kDisable);
+  } while (ChangeCompactOptions());
+}
+
+TEST_P(DBMultiGetTestWithParam, MultiGetBatchedValueSizeMultiLevelMerge) {
+  if (std::get<1>(GetParam())) {
+    ROCKSDB_GTEST_BYPASS("This test needs to be fixed for async IO");
+    return;
+  }
+  // Skip for unbatched MultiGet
+  if (!std::get<0>(GetParam())) {
+    ROCKSDB_GTEST_BYPASS("This test is only for batched MultiGet");
+    return;
+  }
+  Options options = CurrentOptions();
+  options.disable_auto_compactions = true;
+  options.merge_operator = MergeOperators::CreateStringAppendOperator();
+  BlockBasedTableOptions bbto;
+  bbto.filter_policy.reset(NewBloomFilterPolicy(10, false));
+  options.table_factory.reset(NewBlockBasedTableFactory(bbto));
+  Reopen(options);
+  int num_keys = 0;
+
+  for (int i = 0; i < 64; ++i) {
+    ASSERT_OK(Put("key_" + std::to_string(i), "val_l2_" + std::to_string(i)));
+    num_keys++;
+    if (num_keys == 8) {
+      ASSERT_OK(Flush());
+      num_keys = 0;
+    }
+  }
+  if (num_keys > 0) {
+    ASSERT_OK(Flush());
+    num_keys = 0;
+  }
+  MoveFilesToLevel(2);
+
+  for (int i = 0; i < 64; i += 3) {
+    ASSERT_OK(Merge("key_" + std::to_string(i), "val_l1_" + std::to_string(i)));
+    num_keys++;
+    if (num_keys == 8) {
+      ASSERT_OK(Flush());
+      num_keys = 0;
+    }
+  }
+  if (num_keys > 0) {
+    ASSERT_OK(Flush());
+    num_keys = 0;
+  }
+  MoveFilesToLevel(1);
+
+  for (int i = 0; i < 64; i += 5) {
+    ASSERT_OK(Merge("key_" + std::to_string(i), "val_l0_" + std::to_string(i)));
+    num_keys++;
+    if (num_keys == 8) {
+      ASSERT_OK(Flush());
+      num_keys = 0;
+    }
+  }
+  if (num_keys > 0) {
+    ASSERT_OK(Flush());
+    num_keys = 0;
+  }
+  ASSERT_EQ(0, num_keys);
+
+  for (int i = 0; i < 64; i += 9) {
+    ASSERT_OK(
+        Merge("key_" + std::to_string(i), "val_mem_" + std::to_string(i)));
+  }
+
+  std::vector<std::string> keys_str;
+  for (int i = 10; i < 50; ++i) {
+    keys_str.push_back("key_" + std::to_string(i));
+  }
+
+  std::vector<Slice> keys(keys_str.size());
+  for (int i = 0; i < 40; i++) {
+    keys[i] = Slice(keys_str[i]);
+  }
+
+  std::vector<PinnableSlice> values(keys_str.size());
+  std::vector<Status> statuses(keys_str.size());
+  ReadOptions read_options;
+  read_options.verify_checksums = true;
+  read_options.value_size_soft_limit = 380;
+  read_options.async_io = std::get<1>(GetParam());
+  db_->MultiGet(read_options, dbfull()->DefaultColumnFamily(), keys.size(),
+                keys.data(), values.data(), statuses.data());
+
+  ASSERT_EQ(values.size(), keys.size());
+
+  for (unsigned int j = 0; j < 26; ++j) {
+    int key = j + 10;
+    std::string value;
+    value.append("val_l2_" + std::to_string(key));
+    if (key % 3 == 0) {
+      value.append(",");
+      value.append("val_l1_" + std::to_string(key));
+    }
+    if (key % 5 == 0) {
+      value.append(",");
+      value.append("val_l0_" + std::to_string(key));
+    }
+    if (key % 9 == 0) {
+      value.append(",");
+      value.append("val_mem_" + std::to_string(key));
+    }
+    ASSERT_EQ(values[j], value);
+    ASSERT_OK(statuses[j]);
+  }
+
+  // All remaning keys status is set Status::Abort
+  for (unsigned int j = 26; j < 40; j++) {
+    ASSERT_TRUE(statuses[j].IsAborted());
+  }
+}
+
+INSTANTIATE_TEST_CASE_P(DBMultiGetTestWithParam, DBMultiGetTestWithParam,
+                        testing::Combine(testing::Bool(), testing::Bool()));
+
+#if USE_COROUTINES
+class DBMultiGetAsyncIOTest : public DBBasicTest,
+                              public ::testing::WithParamInterface<bool> {
+ public:
+  DBMultiGetAsyncIOTest()
+      : DBBasicTest(), statistics_(ROCKSDB_NAMESPACE::CreateDBStatistics()) {
+    BlockBasedTableOptions bbto;
+    bbto.filter_policy.reset(NewBloomFilterPolicy(10));
+    options_ = CurrentOptions();
+    options_.disable_auto_compactions = true;
+    options_.statistics = statistics_;
+    options_.table_factory.reset(NewBlockBasedTableFactory(bbto));
+    Reopen(options_);
+    int num_keys = 0;
+
+    // Put all keys in the bottommost level, and overwrite some keys
+    // in L0 and L1
+    for (int i = 0; i < 256; ++i) {
+      EXPECT_OK(Put(Key(i), "val_l2_" + std::to_string(i)));
+      num_keys++;
+      if (num_keys == 8) {
+        EXPECT_OK(Flush());
+        num_keys = 0;
+      }
+    }
+    if (num_keys > 0) {
+      EXPECT_OK(Flush());
+      num_keys = 0;
+    }
+    MoveFilesToLevel(2);
+
+    for (int i = 0; i < 128; i += 3) {
+      EXPECT_OK(Put(Key(i), "val_l1_" + std::to_string(i)));
+      num_keys++;
+      if (num_keys == 8) {
+        EXPECT_OK(Flush());
+        num_keys = 0;
+      }
+    }
+    if (num_keys > 0) {
+      EXPECT_OK(Flush());
+      num_keys = 0;
+    }
+    // Put some range deletes in L1
+    for (int i = 128; i < 256; i += 32) {
+      std::string range_begin = Key(i);
+      std::string range_end = Key(i + 16);
+      EXPECT_OK(dbfull()->DeleteRange(WriteOptions(),
+                                      dbfull()->DefaultColumnFamily(),
+                                      range_begin, range_end));
+      // Also do some Puts to force creation of bloom filter
+      for (int j = i + 16; j < i + 32; ++j) {
+        if (j % 3 == 0) {
+          EXPECT_OK(Put(Key(j), "val_l1_" + std::to_string(j)));
+        }
+      }
+      EXPECT_OK(Flush());
+    }
+    MoveFilesToLevel(1);
+
+    for (int i = 0; i < 128; i += 5) {
+      EXPECT_OK(Put(Key(i), "val_l0_" + std::to_string(i)));
+      num_keys++;
+      if (num_keys == 8) {
+        EXPECT_OK(Flush());
+        num_keys = 0;
+      }
+    }
+    if (num_keys > 0) {
+      EXPECT_OK(Flush());
+      num_keys = 0;
+    }
+    EXPECT_EQ(0, num_keys);
+  }
+
+  const std::shared_ptr<Statistics>& statistics() { return statistics_; }
+
+ protected:
+  void ReopenDB() { Reopen(options_); }
+
+ private:
+  std::shared_ptr<Statistics> statistics_;
+  Options options_;
+};
+
+TEST_P(DBMultiGetAsyncIOTest, GetFromL0) {
+  // All 3 keys in L0. The L0 files should be read serially.
+  std::vector<std::string> key_strs{Key(0), Key(40), Key(80)};
+  std::vector<Slice> keys{key_strs[0], key_strs[1], key_strs[2]};
+  std::vector<PinnableSlice> values(key_strs.size());
+  std::vector<Status> statuses(key_strs.size());
+
+  ReadOptions ro;
+  ro.async_io = true;
+  ro.optimize_multiget_for_io = GetParam();
+  dbfull()->MultiGet(ro, dbfull()->DefaultColumnFamily(), keys.size(),
+                     keys.data(), values.data(), statuses.data());
+  ASSERT_EQ(values.size(), 3);
+  ASSERT_OK(statuses[0]);
+  ASSERT_OK(statuses[1]);
+  ASSERT_OK(statuses[2]);
+  ASSERT_EQ(values[0], "val_l0_" + std::to_string(0));
+  ASSERT_EQ(values[1], "val_l0_" + std::to_string(40));
+  ASSERT_EQ(values[2], "val_l0_" + std::to_string(80));
+
+  HistogramData multiget_io_batch_size;
+
+  statistics()->histogramData(MULTIGET_IO_BATCH_SIZE, &multiget_io_batch_size);
+
+  // With async IO, lookups will happen in parallel for each key
+  if (GetParam()) {
+    ASSERT_EQ(multiget_io_batch_size.count, 1);
+    ASSERT_EQ(multiget_io_batch_size.max, 3);
+    ASSERT_EQ(statistics()->getTickerCount(MULTIGET_COROUTINE_COUNT), 3);
+  } else {
+    // Without Async IO, MultiGet will call MultiRead 3 times, once for each
+    // L0 file
+    ASSERT_EQ(multiget_io_batch_size.count, 3);
+  }
+}
+
+TEST_P(DBMultiGetAsyncIOTest, GetFromL1) {
+  std::vector<std::string> key_strs;
+  std::vector<Slice> keys;
+  std::vector<PinnableSlice> values;
+  std::vector<Status> statuses;
+
+  key_strs.push_back(Key(33));
+  key_strs.push_back(Key(54));
+  key_strs.push_back(Key(102));
+  keys.push_back(key_strs[0]);
+  keys.push_back(key_strs[1]);
+  keys.push_back(key_strs[2]);
+  values.resize(keys.size());
+  statuses.resize(keys.size());
+
+  ReadOptions ro;
+  ro.async_io = true;
+  ro.optimize_multiget_for_io = GetParam();
+  dbfull()->MultiGet(ro, dbfull()->DefaultColumnFamily(), keys.size(),
+                     keys.data(), values.data(), statuses.data());
+  ASSERT_EQ(values.size(), 3);
+  ASSERT_EQ(statuses[0], Status::OK());
+  ASSERT_EQ(statuses[1], Status::OK());
+  ASSERT_EQ(statuses[2], Status::OK());
+  ASSERT_EQ(values[0], "val_l1_" + std::to_string(33));
+  ASSERT_EQ(values[1], "val_l1_" + std::to_string(54));
+  ASSERT_EQ(values[2], "val_l1_" + std::to_string(102));
+
+  HistogramData multiget_io_batch_size;
+
+  statistics()->histogramData(MULTIGET_IO_BATCH_SIZE, &multiget_io_batch_size);
+
+  // A batch of 3 async IOs is expected, one for each overlapping file in L1
+  ASSERT_EQ(multiget_io_batch_size.count, 1);
+  ASSERT_EQ(multiget_io_batch_size.max, 3);
+  ASSERT_EQ(statistics()->getTickerCount(MULTIGET_COROUTINE_COUNT), 3);
+}
+
+TEST_P(DBMultiGetAsyncIOTest, GetFromL1Error) {
+  std::vector<std::string> key_strs;
+  std::vector<Slice> keys;
+  std::vector<PinnableSlice> values;
+  std::vector<Status> statuses;
+
+  key_strs.push_back(Key(33));
+  key_strs.push_back(Key(54));
+  key_strs.push_back(Key(102));
+  keys.push_back(key_strs[0]);
+  keys.push_back(key_strs[1]);
+  keys.push_back(key_strs[2]);
+  values.resize(keys.size());
+  statuses.resize(keys.size());
+
+  SyncPoint::GetInstance()->SetCallBack(
+      "TableCache::GetTableReader:BeforeOpenFile", [&](void* status) {
+        static int count = 0;
+        count++;
+        // Fail the last table reader open, which is the 6th SST file
+        // since 3 overlapping L0 files + 3 L1 files containing the keys
+        if (count == 6) {
+          Status* s = static_cast<Status*>(status);
+          *s = Status::IOError();
+        }
+      });
+  // DB open will create table readers unless we reduce the table cache
+  // capacity.
+  // SanitizeOptions will set max_open_files to minimum of 20. Table cache
+  // is allocated with max_open_files - 10 as capacity. So override
+  // max_open_files to 11 so table cache capacity will become 1. This will
+  // prevent file open during DB open and force the file to be opened
+  // during MultiGet
+  SyncPoint::GetInstance()->SetCallBack(
+      "SanitizeOptions::AfterChangeMaxOpenFiles", [&](void* arg) {
+        int* max_open_files = (int*)arg;
+        *max_open_files = 11;
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  ReopenDB();
+
+  ReadOptions ro;
+  ro.async_io = true;
+  ro.optimize_multiget_for_io = GetParam();
+  dbfull()->MultiGet(ro, dbfull()->DefaultColumnFamily(), keys.size(),
+                     keys.data(), values.data(), statuses.data());
+  SyncPoint::GetInstance()->DisableProcessing();
+  ASSERT_EQ(values.size(), 3);
+  ASSERT_EQ(statuses[0], Status::OK());
+  ASSERT_EQ(statuses[1], Status::OK());
+  ASSERT_EQ(statuses[2], Status::IOError());
+
+  HistogramData multiget_io_batch_size;
+
+  statistics()->histogramData(MULTIGET_IO_BATCH_SIZE, &multiget_io_batch_size);
+
+  // A batch of 3 async IOs is expected, one for each overlapping file in L1
+  ASSERT_EQ(multiget_io_batch_size.count, 1);
+  ASSERT_EQ(multiget_io_batch_size.max, 2);
+  ASSERT_EQ(statistics()->getTickerCount(MULTIGET_COROUTINE_COUNT), 2);
+}
+
+TEST_P(DBMultiGetAsyncIOTest, LastKeyInFile) {
+  std::vector<std::string> key_strs;
+  std::vector<Slice> keys;
+  std::vector<PinnableSlice> values;
+  std::vector<Status> statuses;
+
+  // 21 is the last key in the first L1 file
+  key_strs.push_back(Key(21));
+  key_strs.push_back(Key(54));
+  key_strs.push_back(Key(102));
+  keys.push_back(key_strs[0]);
+  keys.push_back(key_strs[1]);
+  keys.push_back(key_strs[2]);
+  values.resize(keys.size());
+  statuses.resize(keys.size());
+
+  ReadOptions ro;
+  ro.async_io = true;
+  ro.optimize_multiget_for_io = GetParam();
+  dbfull()->MultiGet(ro, dbfull()->DefaultColumnFamily(), keys.size(),
+                     keys.data(), values.data(), statuses.data());
+  ASSERT_EQ(values.size(), 3);
+  ASSERT_EQ(statuses[0], Status::OK());
+  ASSERT_EQ(statuses[1], Status::OK());
+  ASSERT_EQ(statuses[2], Status::OK());
+  ASSERT_EQ(values[0], "val_l1_" + std::to_string(21));
+  ASSERT_EQ(values[1], "val_l1_" + std::to_string(54));
+  ASSERT_EQ(values[2], "val_l1_" + std::to_string(102));
+
+  HistogramData multiget_io_batch_size;
+
+  statistics()->histogramData(MULTIGET_IO_BATCH_SIZE, &multiget_io_batch_size);
+
+  // Since the first MultiGet key is the last key in a file, the MultiGet is
+  // expected to lookup in that file first, before moving on to other files.
+  // So the first file lookup will issue one async read, and the next lookup
+  // will lookup 2 files in parallel and issue 2 async reads
+  ASSERT_EQ(multiget_io_batch_size.count, 2);
+  ASSERT_EQ(multiget_io_batch_size.max, 2);
+}
+
+TEST_P(DBMultiGetAsyncIOTest, GetFromL1AndL2) {
+  std::vector<std::string> key_strs;
+  std::vector<Slice> keys;
+  std::vector<PinnableSlice> values;
+  std::vector<Status> statuses;
+
+  // 33 and 102 are in L1, and 56 is in L2
+  key_strs.push_back(Key(33));
+  key_strs.push_back(Key(56));
+  key_strs.push_back(Key(102));
+  keys.push_back(key_strs[0]);
+  keys.push_back(key_strs[1]);
+  keys.push_back(key_strs[2]);
+  values.resize(keys.size());
+  statuses.resize(keys.size());
+
+  ReadOptions ro;
+  ro.async_io = true;
+  ro.optimize_multiget_for_io = GetParam();
+  dbfull()->MultiGet(ro, dbfull()->DefaultColumnFamily(), keys.size(),
+                     keys.data(), values.data(), statuses.data());
+  ASSERT_EQ(values.size(), 3);
+  ASSERT_EQ(statuses[0], Status::OK());
+  ASSERT_EQ(statuses[1], Status::OK());
+  ASSERT_EQ(statuses[2], Status::OK());
+  ASSERT_EQ(values[0], "val_l1_" + std::to_string(33));
+  ASSERT_EQ(values[1], "val_l2_" + std::to_string(56));
+  ASSERT_EQ(values[2], "val_l1_" + std::to_string(102));
+
+  HistogramData multiget_io_batch_size;
+
+  statistics()->histogramData(MULTIGET_IO_BATCH_SIZE, &multiget_io_batch_size);
+
+  // There are 2 keys in L1 in twp separate files, and 1 in L2. With
+  // optimize_multiget_for_io, all three lookups will happen in parallel.
+  // Otherwise, the L2 lookup will happen after L1.
+  ASSERT_EQ(multiget_io_batch_size.count, GetParam() ? 1 : 2);
+  ASSERT_EQ(multiget_io_batch_size.max, GetParam() ? 3 : 2);
+}
+
+TEST_P(DBMultiGetAsyncIOTest, GetFromL2WithRangeOverlapL0L1) {
+  std::vector<std::string> key_strs;
+  std::vector<Slice> keys;
+  std::vector<PinnableSlice> values;
+  std::vector<Status> statuses;
+
+  // 19 and 26 are in L2, but overlap with L0 and L1 file ranges
+  key_strs.push_back(Key(19));
+  key_strs.push_back(Key(26));
+  keys.push_back(key_strs[0]);
+  keys.push_back(key_strs[1]);
+  values.resize(keys.size());
+  statuses.resize(keys.size());
+
+  ReadOptions ro;
+  ro.async_io = true;
+  ro.optimize_multiget_for_io = GetParam();
+  dbfull()->MultiGet(ro, dbfull()->DefaultColumnFamily(), keys.size(),
+                     keys.data(), values.data(), statuses.data());
+  ASSERT_EQ(values.size(), 2);
+  ASSERT_EQ(statuses[0], Status::OK());
+  ASSERT_EQ(statuses[1], Status::OK());
+  ASSERT_EQ(values[0], "val_l2_" + std::to_string(19));
+  ASSERT_EQ(values[1], "val_l2_" + std::to_string(26));
+
+  // Bloom filters in L0/L1 will avoid the coroutine calls in those levels
+  ASSERT_EQ(statistics()->getTickerCount(MULTIGET_COROUTINE_COUNT), 2);
+}
+
+TEST_P(DBMultiGetAsyncIOTest, GetFromL2WithRangeDelInL1) {
+  std::vector<std::string> key_strs;
+  std::vector<Slice> keys;
+  std::vector<PinnableSlice> values;
+  std::vector<Status> statuses;
+
+  // 139 and 163 are in L2, but overlap with a range deletes in L1
+  key_strs.push_back(Key(139));
+  key_strs.push_back(Key(163));
+  keys.push_back(key_strs[0]);
+  keys.push_back(key_strs[1]);
+  values.resize(keys.size());
+  statuses.resize(keys.size());
+
+  ReadOptions ro;
+  ro.async_io = true;
+  ro.optimize_multiget_for_io = GetParam();
+  dbfull()->MultiGet(ro, dbfull()->DefaultColumnFamily(), keys.size(),
+                     keys.data(), values.data(), statuses.data());
+  ASSERT_EQ(values.size(), 2);
+  ASSERT_EQ(statuses[0], Status::NotFound());
+  ASSERT_EQ(statuses[1], Status::NotFound());
+
+  // Bloom filters in L0/L1 will avoid the coroutine calls in those levels
+  ASSERT_EQ(statistics()->getTickerCount(MULTIGET_COROUTINE_COUNT), 2);
+}
+
+TEST_P(DBMultiGetAsyncIOTest, GetFromL1AndL2WithRangeDelInL1) {
+  std::vector<std::string> key_strs;
+  std::vector<Slice> keys;
+  std::vector<PinnableSlice> values;
+  std::vector<Status> statuses;
+
+  // 139 and 163 are in L2, but overlap with a range deletes in L1
+  key_strs.push_back(Key(139));
+  key_strs.push_back(Key(144));
+  key_strs.push_back(Key(163));
+  keys.push_back(key_strs[0]);
+  keys.push_back(key_strs[1]);
+  keys.push_back(key_strs[2]);
+  values.resize(keys.size());
+  statuses.resize(keys.size());
+
+  ReadOptions ro;
+  ro.async_io = true;
+  ro.optimize_multiget_for_io = GetParam();
+  dbfull()->MultiGet(ro, dbfull()->DefaultColumnFamily(), keys.size(),
+                     keys.data(), values.data(), statuses.data());
+  ASSERT_EQ(values.size(), keys.size());
+  ASSERT_EQ(statuses[0], Status::NotFound());
+  ASSERT_EQ(statuses[1], Status::OK());
+  ASSERT_EQ(values[1], "val_l1_" + std::to_string(144));
+  ASSERT_EQ(statuses[2], Status::NotFound());
+
+  // Bloom filters in L0/L1 will avoid the coroutine calls in those levels
+  ASSERT_EQ(statistics()->getTickerCount(MULTIGET_COROUTINE_COUNT), 3);
+}
+
+INSTANTIATE_TEST_CASE_P(DBMultiGetAsyncIOTest, DBMultiGetAsyncIOTest,
+                        testing::Bool());
+#endif  // USE_COROUTINES
+
+TEST_F(DBBasicTest, MultiGetStats) {
+  Options options;
+  options.create_if_missing = true;
+  options.disable_auto_compactions = true;
+  options.env = env_;
+  options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
+  BlockBasedTableOptions table_options;
+  table_options.block_size = 1;
+  table_options.index_type =
+      BlockBasedTableOptions::IndexType::kTwoLevelIndexSearch;
+  table_options.partition_filters = true;
+  table_options.no_block_cache = true;
+  table_options.cache_index_and_filter_blocks = false;
+  table_options.filter_policy.reset(NewBloomFilterPolicy(10, false));
+  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+  CreateAndReopenWithCF({"pikachu"}, options);
+
+  int total_keys = 2000;
+  std::vector<std::string> keys_str(total_keys);
+  std::vector<Slice> keys(total_keys);
+  static size_t kMultiGetBatchSize = 100;
+  std::vector<PinnableSlice> values(kMultiGetBatchSize);
+  std::vector<Status> s(kMultiGetBatchSize);
+  ReadOptions read_opts;
+
+  Random rnd(309);
+  // Create Multiple SST files at multiple levels.
+  for (int i = 0; i < 500; ++i) {
+    keys_str[i] = "k" + std::to_string(i);
+    keys[i] = Slice(keys_str[i]);
+    ASSERT_OK(Put(1, "k" + std::to_string(i), rnd.RandomString(1000)));
+    if (i % 100 == 0) {
+      ASSERT_OK(Flush(1));
+    }
+  }
+  ASSERT_OK(Flush(1));
+  MoveFilesToLevel(2, 1);
+
+  for (int i = 501; i < 1000; ++i) {
+    keys_str[i] = "k" + std::to_string(i);
+    keys[i] = Slice(keys_str[i]);
+    ASSERT_OK(Put(1, "k" + std::to_string(i), rnd.RandomString(1000)));
+    if (i % 100 == 0) {
+      ASSERT_OK(Flush(1));
+    }
+  }
+
+  ASSERT_OK(Flush(1));
+  MoveFilesToLevel(2, 1);
+
+  for (int i = 1001; i < total_keys; ++i) {
+    keys_str[i] = "k" + std::to_string(i);
+    keys[i] = Slice(keys_str[i]);
+    ASSERT_OK(Put(1, "k" + std::to_string(i), rnd.RandomString(1000)));
+    if (i % 100 == 0) {
+      ASSERT_OK(Flush(1));
+    }
+  }
+  ASSERT_OK(Flush(1));
+  MoveFilesToLevel(1, 1);
+  Close();
+
+  ReopenWithColumnFamilies({"default", "pikachu"}, options);
+  ASSERT_OK(options.statistics->Reset());
+
+  db_->MultiGet(read_opts, handles_[1], kMultiGetBatchSize, &keys[1250],
+                values.data(), s.data(), false);
+
+  ASSERT_EQ(values.size(), kMultiGetBatchSize);
+  HistogramData hist_level;
+  HistogramData hist_index_and_filter_blocks;
+  HistogramData hist_sst;
+
+  options.statistics->histogramData(NUM_LEVEL_READ_PER_MULTIGET, &hist_level);
+  options.statistics->histogramData(NUM_INDEX_AND_FILTER_BLOCKS_READ_PER_LEVEL,
+                                    &hist_index_and_filter_blocks);
+  options.statistics->histogramData(NUM_SST_READ_PER_LEVEL, &hist_sst);
+
+  // Maximum number of blocks read from a file system in a level.
+  ASSERT_EQ(hist_level.max, 1);
+  ASSERT_GT(hist_index_and_filter_blocks.max, 0);
+  // Maximum number of sst files read from file system in a level.
+  ASSERT_EQ(hist_sst.max, 2);
+
+  // Minimun number of blocks read in a level.
+  ASSERT_EQ(hist_level.min, 1);
+  ASSERT_GT(hist_index_and_filter_blocks.min, 0);
+  // Minimun number of sst files read in a level.
+  ASSERT_EQ(hist_sst.min, 1);
+
+  for (PinnableSlice& value : values) {
+    value.Reset();
+  }
+  for (Status& status : s) {
+    status = Status::OK();
+  }
+  db_->MultiGet(read_opts, handles_[1], kMultiGetBatchSize, &keys[950],
+                values.data(), s.data(), false);
+  options.statistics->histogramData(NUM_LEVEL_READ_PER_MULTIGET, &hist_level);
+  ASSERT_EQ(hist_level.max, 2);
+}
+
+// Test class for batched MultiGet with prefix extractor
+// Param bool - If true, use partitioned filters
+//              If false, use full filter block
+class MultiGetPrefixExtractorTest : public DBBasicTest,
+                                    public ::testing::WithParamInterface<bool> {
+};
+
+TEST_P(MultiGetPrefixExtractorTest, Batched) {
+  Options options = CurrentOptions();
+  options.prefix_extractor.reset(NewFixedPrefixTransform(2));
+  options.memtable_prefix_bloom_size_ratio = 10;
+  BlockBasedTableOptions bbto;
+  if (GetParam()) {
+    bbto.index_type = BlockBasedTableOptions::IndexType::kTwoLevelIndexSearch;
+    bbto.partition_filters = true;
+  }
+  bbto.filter_policy.reset(NewBloomFilterPolicy(10, false));
+  bbto.whole_key_filtering = false;
+  bbto.cache_index_and_filter_blocks = false;
+  options.table_factory.reset(NewBlockBasedTableFactory(bbto));
+  Reopen(options);
+
+  SetPerfLevel(kEnableCount);
+  get_perf_context()->Reset();
+
+  ASSERT_OK(Put("k", "v0"));
+  ASSERT_OK(Put("kk1", "v1"));
+  ASSERT_OK(Put("kk2", "v2"));
+  ASSERT_OK(Put("kk3", "v3"));
+  ASSERT_OK(Put("kk4", "v4"));
+  std::vector<std::string> keys(
+      {"k", "kk1", "kk2", "kk3", "kk4", "rofl", "lmho"});
+  std::vector<std::string> expected(
+      {"v0", "v1", "v2", "v3", "v4", "NOT_FOUND", "NOT_FOUND"});
+  std::vector<std::string> values;
+  values = MultiGet(keys, nullptr);
+  ASSERT_EQ(values, expected);
+  // One key ("k") is not queried against the filter because it is outside
+  // the prefix_extractor domain, leaving 6 keys with queried prefixes.
+  ASSERT_EQ(get_perf_context()->bloom_memtable_miss_count, 2);
+  ASSERT_EQ(get_perf_context()->bloom_memtable_hit_count, 4);
+  ASSERT_OK(Flush());
+
+  get_perf_context()->Reset();
+  values = MultiGet(keys, nullptr);
+  ASSERT_EQ(values, expected);
+  ASSERT_EQ(get_perf_context()->bloom_sst_miss_count, 2);
+  ASSERT_EQ(get_perf_context()->bloom_sst_hit_count, 4);
+
+  // Also check Get stat
+  get_perf_context()->Reset();
+  for (size_t i = 0; i < keys.size(); ++i) {
+    values[i] = Get(keys[i]);
+  }
+  ASSERT_EQ(values, expected);
+  ASSERT_EQ(get_perf_context()->bloom_sst_miss_count, 2);
+  ASSERT_EQ(get_perf_context()->bloom_sst_hit_count, 4);
+}
+
+INSTANTIATE_TEST_CASE_P(MultiGetPrefix, MultiGetPrefixExtractorTest,
+                        ::testing::Bool());
+
+#ifndef ROCKSDB_LITE
+class DBMultiGetRowCacheTest : public DBBasicTest,
+                               public ::testing::WithParamInterface<bool> {};
+
+TEST_P(DBMultiGetRowCacheTest, MultiGetBatched) {
+  do {
+    option_config_ = kRowCache;
+    Options options = CurrentOptions();
+    options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
+    CreateAndReopenWithCF({"pikachu"}, options);
+    SetPerfLevel(kEnableCount);
+    ASSERT_OK(Put(1, "k1", "v1"));
+    ASSERT_OK(Put(1, "k2", "v2"));
+    ASSERT_OK(Put(1, "k3", "v3"));
+    ASSERT_OK(Put(1, "k4", "v4"));
+    ASSERT_OK(Flush(1));
+    ASSERT_OK(Put(1, "k5", "v5"));
+    const Snapshot* snap1 = dbfull()->GetSnapshot();
+    ASSERT_OK(Delete(1, "k4"));
+    ASSERT_OK(Flush(1));
+    const Snapshot* snap2 = dbfull()->GetSnapshot();
+
+    get_perf_context()->Reset();
+
+    std::vector<Slice> keys({"no_key", "k5", "k4", "k3", "k1"});
+    std::vector<PinnableSlice> values(keys.size());
+    std::vector<ColumnFamilyHandle*> cfs(keys.size(), handles_[1]);
+    std::vector<Status> s(keys.size());
+
+    ReadOptions ro;
+    bool use_snapshots = GetParam();
+    if (use_snapshots) {
+      ro.snapshot = snap2;
+    }
+    db_->MultiGet(ro, handles_[1], keys.size(), keys.data(), values.data(),
+                  s.data(), false);
+
+    ASSERT_EQ(values.size(), keys.size());
+    ASSERT_EQ(std::string(values[4].data(), values[4].size()), "v1");
+    ASSERT_EQ(std::string(values[3].data(), values[3].size()), "v3");
+    ASSERT_EQ(std::string(values[1].data(), values[1].size()), "v5");
+    // four kv pairs * two bytes per value
+    ASSERT_EQ(6, (int)get_perf_context()->multiget_read_bytes);
+
+    ASSERT_TRUE(s[0].IsNotFound());
+    ASSERT_OK(s[1]);
+    ASSERT_TRUE(s[2].IsNotFound());
+    ASSERT_OK(s[3]);
+    ASSERT_OK(s[4]);
+
+    // Call MultiGet() again with some intersection with the previous set of
+    // keys. Those should already be in the row cache.
+    keys.assign({"no_key", "k5", "k3", "k2"});
+    for (size_t i = 0; i < keys.size(); ++i) {
+      values[i].Reset();
+      s[i] = Status::OK();
+    }
+    get_perf_context()->Reset();
+
+    if (use_snapshots) {
+      ro.snapshot = snap1;
+    }
+    db_->MultiGet(ReadOptions(), handles_[1], keys.size(), keys.data(),
+                  values.data(), s.data(), false);
+
+    ASSERT_EQ(std::string(values[3].data(), values[3].size()), "v2");
+    ASSERT_EQ(std::string(values[2].data(), values[2].size()), "v3");
+    ASSERT_EQ(std::string(values[1].data(), values[1].size()), "v5");
+    // four kv pairs * two bytes per value
+    ASSERT_EQ(6, (int)get_perf_context()->multiget_read_bytes);
+
+    ASSERT_TRUE(s[0].IsNotFound());
+    ASSERT_OK(s[1]);
+    ASSERT_OK(s[2]);
+    ASSERT_OK(s[3]);
+    if (use_snapshots) {
+      // Only reads from the first SST file would have been cached, since
+      // snapshot seq no is > fd.largest_seqno
+      ASSERT_EQ(1, TestGetTickerCount(options, ROW_CACHE_HIT));
+    } else {
+      ASSERT_EQ(2, TestGetTickerCount(options, ROW_CACHE_HIT));
+    }
+
+    SetPerfLevel(kDisable);
+    dbfull()->ReleaseSnapshot(snap1);
+    dbfull()->ReleaseSnapshot(snap2);
+  } while (ChangeCompactOptions());
+}
+
+INSTANTIATE_TEST_CASE_P(DBMultiGetRowCacheTest, DBMultiGetRowCacheTest,
+                        testing::Values(true, false));
+
+TEST_F(DBBasicTest, GetAllKeyVersions) {
+  Options options = CurrentOptions();
+  options.env = env_;
+  options.create_if_missing = true;
+  options.disable_auto_compactions = true;
+  CreateAndReopenWithCF({"pikachu"}, options);
+  ASSERT_EQ(2, handles_.size());
+  const size_t kNumInserts = 4;
+  const size_t kNumDeletes = 4;
+  const size_t kNumUpdates = 4;
+
+  // Check default column family
+  for (size_t i = 0; i != kNumInserts; ++i) {
+    ASSERT_OK(Put(std::to_string(i), "value"));
+  }
+  for (size_t i = 0; i != kNumUpdates; ++i) {
+    ASSERT_OK(Put(std::to_string(i), "value1"));
+  }
+  for (size_t i = 0; i != kNumDeletes; ++i) {
+    ASSERT_OK(Delete(std::to_string(i)));
+  }
+  std::vector<KeyVersion> key_versions;
+  ASSERT_OK(GetAllKeyVersions(db_, Slice(), Slice(),
+                              std::numeric_limits<size_t>::max(),
+                              &key_versions));
+  ASSERT_EQ(kNumInserts + kNumDeletes + kNumUpdates, key_versions.size());
+  for (size_t i = 0; i < kNumInserts + kNumDeletes + kNumUpdates; i++) {
+    if (i % 3 == 0) {
+      ASSERT_EQ(key_versions[i].GetTypeName(), "TypeDeletion");
+    } else {
+      ASSERT_EQ(key_versions[i].GetTypeName(), "TypeValue");
+    }
+  }
+  ASSERT_OK(GetAllKeyVersions(db_, handles_[0], Slice(), Slice(),
+                              std::numeric_limits<size_t>::max(),
+                              &key_versions));
+  ASSERT_EQ(kNumInserts + kNumDeletes + kNumUpdates, key_versions.size());
+
+  // Check non-default column family
+  for (size_t i = 0; i + 1 != kNumInserts; ++i) {
+    ASSERT_OK(Put(1, std::to_string(i), "value"));
+  }
+  for (size_t i = 0; i + 1 != kNumUpdates; ++i) {
+    ASSERT_OK(Put(1, std::to_string(i), "value1"));
+  }
+  for (size_t i = 0; i + 1 != kNumDeletes; ++i) {
+    ASSERT_OK(Delete(1, std::to_string(i)));
+  }
+  ASSERT_OK(GetAllKeyVersions(db_, handles_[1], Slice(), Slice(),
+                              std::numeric_limits<size_t>::max(),
+                              &key_versions));
+  ASSERT_EQ(kNumInserts + kNumDeletes + kNumUpdates - 3, key_versions.size());
+}
+
+TEST_F(DBBasicTest, ValueTypeString) {
+  KeyVersion key_version;
+  // when adding new type, please also update `value_type_string_map`
+  for (unsigned char i = ValueType::kTypeDeletion; i < ValueType::kTypeMaxValid;
+       i++) {
+    key_version.type = i;
+    ASSERT_TRUE(key_version.GetTypeName() != "Invalid");
+  }
+}
+#endif  // !ROCKSDB_LITE
+
+TEST_F(DBBasicTest, MultiGetIOBufferOverrun) {
+  Options options = CurrentOptions();
+  Random rnd(301);
+  BlockBasedTableOptions table_options;
+  table_options.pin_l0_filter_and_index_blocks_in_cache = true;
+  table_options.block_size = 16 * 1024;
+  ASSERT_TRUE(table_options.block_size >
+              BlockBasedTable::kMultiGetReadStackBufSize);
+  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+  Reopen(options);
+
+  std::string zero_str(128, '\0');
+  for (int i = 0; i < 100; ++i) {
+    // Make the value compressible. A purely random string doesn't compress
+    // and the resultant data block will not be compressed
+    std::string value(rnd.RandomString(128) + zero_str);
+    assert(Put(Key(i), value) == Status::OK());
+  }
+  ASSERT_OK(Flush());
+
+  std::vector<std::string> key_data(10);
+  std::vector<Slice> keys;
+  // We cannot resize a PinnableSlice vector, so just set initial size to
+  // largest we think we will need
+  std::vector<PinnableSlice> values(10);
+  std::vector<Status> statuses;
+  ReadOptions ro;
+
+  // Warm up the cache first
+  key_data.emplace_back(Key(0));
+  keys.emplace_back(Slice(key_data.back()));
+  key_data.emplace_back(Key(50));
+  keys.emplace_back(Slice(key_data.back()));
+  statuses.resize(keys.size());
+
+  dbfull()->MultiGet(ro, dbfull()->DefaultColumnFamily(), keys.size(),
+                     keys.data(), values.data(), statuses.data(), true);
+}
+
+TEST_F(DBBasicTest, IncrementalRecoveryNoCorrupt) {
+  Options options = CurrentOptions();
+  DestroyAndReopen(options);
+  CreateAndReopenWithCF({"pikachu", "eevee"}, options);
+  size_t num_cfs = handles_.size();
+  ASSERT_EQ(3, num_cfs);
+  WriteOptions write_opts;
+  write_opts.disableWAL = true;
+  for (size_t cf = 0; cf != num_cfs; ++cf) {
+    for (size_t i = 0; i != 10000; ++i) {
+      std::string key_str = Key(static_cast<int>(i));
+      std::string value_str = std::to_string(cf) + "_" + std::to_string(i);
+
+      ASSERT_OK(Put(static_cast<int>(cf), key_str, value_str));
+      if (0 == (i % 1000)) {
+        ASSERT_OK(Flush(static_cast<int>(cf)));
+      }
+    }
+  }
+  for (size_t cf = 0; cf != num_cfs; ++cf) {
+    ASSERT_OK(Flush(static_cast<int>(cf)));
+  }
+  Close();
+  options.best_efforts_recovery = true;
+  ReopenWithColumnFamilies({kDefaultColumnFamilyName, "pikachu", "eevee"},
+                           options);
+  num_cfs = handles_.size();
+  ASSERT_EQ(3, num_cfs);
+  for (size_t cf = 0; cf != num_cfs; ++cf) {
+    for (int i = 0; i != 10000; ++i) {
+      std::string key_str = Key(static_cast<int>(i));
+      std::string expected_value_str =
+          std::to_string(cf) + "_" + std::to_string(i);
+      ASSERT_EQ(expected_value_str, Get(static_cast<int>(cf), key_str));
+    }
+  }
+}
+
+TEST_F(DBBasicTest, BestEffortsRecoveryWithVersionBuildingFailure) {
+  Options options = CurrentOptions();
+  DestroyAndReopen(options);
+  ASSERT_OK(Put("foo", "value"));
+  ASSERT_OK(Flush());
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  SyncPoint::GetInstance()->SetCallBack(
+      "VersionBuilder::CheckConsistencyBeforeReturn", [&](void* arg) {
+        ASSERT_NE(nullptr, arg);
+        *(reinterpret_cast<Status*>(arg)) =
+            Status::Corruption("Inject corruption");
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  options.best_efforts_recovery = true;
+  Status s = TryReopen(options);
+  ASSERT_TRUE(s.IsCorruption());
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+}
+
+#ifndef ROCKSDB_LITE
+namespace {
+class TableFileListener : public EventListener {
+ public:
+  void OnTableFileCreated(const TableFileCreationInfo& info) override {
+    InstrumentedMutexLock lock(&mutex_);
+    cf_to_paths_[info.cf_name].push_back(info.file_path);
+  }
+  std::vector<std::string>& GetFiles(const std::string& cf_name) {
+    InstrumentedMutexLock lock(&mutex_);
+    return cf_to_paths_[cf_name];
+  }
+
+ private:
+  InstrumentedMutex mutex_;
+  std::unordered_map<std::string, std::vector<std::string>> cf_to_paths_;
+};
+}  // anonymous namespace
+
+TEST_F(DBBasicTest, LastSstFileNotInManifest) {
+  // If the last sst file is not tracked in MANIFEST,
+  // or the VersionEdit for the last sst file is not synced,
+  // on recovery, the last sst file should be deleted,
+  // and new sst files shouldn't reuse its file number.
+  Options options = CurrentOptions();
+  DestroyAndReopen(options);
+  Close();
+
+  // Manually add a sst file.
+  constexpr uint64_t kSstFileNumber = 100;
+  const std::string kSstFile = MakeTableFileName(dbname_, kSstFileNumber);
+  ASSERT_OK(WriteStringToFile(env_, /* data = */ "bad sst file content",
+                              /* fname = */ kSstFile,
+                              /* should_sync = */ true));
+  ASSERT_OK(env_->FileExists(kSstFile));
+
+  TableFileListener* listener = new TableFileListener();
+  options.listeners.emplace_back(listener);
+  Reopen(options);
+  // kSstFile should already be deleted.
+  ASSERT_TRUE(env_->FileExists(kSstFile).IsNotFound());
+
+  ASSERT_OK(Put("k", "v"));
+  ASSERT_OK(Flush());
+  // New sst file should have file number > kSstFileNumber.
+  std::vector<std::string>& files =
+      listener->GetFiles(kDefaultColumnFamilyName);
+  ASSERT_EQ(files.size(), 1);
+  const std::string fname = files[0].erase(0, (dbname_ + "/").size());
+  uint64_t number = 0;
+  FileType type = kTableFile;
+  ASSERT_TRUE(ParseFileName(fname, &number, &type));
+  ASSERT_EQ(type, kTableFile);
+  ASSERT_GT(number, kSstFileNumber);
+}
+
+TEST_F(DBBasicTest, RecoverWithMissingFiles) {
+  Options options = CurrentOptions();
+  DestroyAndReopen(options);
+  TableFileListener* listener = new TableFileListener();
+  // Disable auto compaction to simplify SST file name tracking.
+  options.disable_auto_compactions = true;
+  options.listeners.emplace_back(listener);
+  CreateAndReopenWithCF({"pikachu", "eevee"}, options);
+  std::vector<std::string> all_cf_names = {kDefaultColumnFamilyName, "pikachu",
+                                           "eevee"};
+  size_t num_cfs = handles_.size();
+  ASSERT_EQ(3, num_cfs);
+  for (size_t cf = 0; cf != num_cfs; ++cf) {
+    ASSERT_OK(Put(static_cast<int>(cf), "a", "0_value"));
+    ASSERT_OK(Flush(static_cast<int>(cf)));
+    ASSERT_OK(Put(static_cast<int>(cf), "b", "0_value"));
+    ASSERT_OK(Flush(static_cast<int>(cf)));
+    ASSERT_OK(Put(static_cast<int>(cf), "c", "0_value"));
+    ASSERT_OK(Flush(static_cast<int>(cf)));
+  }
+
+  // Delete and corrupt files
+  for (size_t i = 0; i < all_cf_names.size(); ++i) {
+    std::vector<std::string>& files = listener->GetFiles(all_cf_names[i]);
+    ASSERT_EQ(3, files.size());
+    std::string corrupted_data;
+    ASSERT_OK(ReadFileToString(env_, files[files.size() - 1], &corrupted_data));
+    ASSERT_OK(WriteStringToFile(
+        env_, corrupted_data.substr(0, corrupted_data.size() - 2),
+        files[files.size() - 1], /*should_sync=*/true));
+    for (int j = static_cast<int>(files.size() - 2); j >= static_cast<int>(i);
+         --j) {
+      ASSERT_OK(env_->DeleteFile(files[j]));
+    }
+  }
+  options.best_efforts_recovery = true;
+  ReopenWithColumnFamilies(all_cf_names, options);
+  // Verify data
+  ReadOptions read_opts;
+  read_opts.total_order_seek = true;
+  {
+    std::unique_ptr<Iterator> iter(db_->NewIterator(read_opts, handles_[0]));
+    iter->SeekToFirst();
+    ASSERT_FALSE(iter->Valid());
+    ASSERT_OK(iter->status());
+    iter.reset(db_->NewIterator(read_opts, handles_[1]));
+    iter->SeekToFirst();
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ("a", iter->key());
+    iter->Next();
+    ASSERT_FALSE(iter->Valid());
+    ASSERT_OK(iter->status());
+    iter.reset(db_->NewIterator(read_opts, handles_[2]));
+    iter->SeekToFirst();
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ("a", iter->key());
+    iter->Next();
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ("b", iter->key());
+    iter->Next();
+    ASSERT_FALSE(iter->Valid());
+    ASSERT_OK(iter->status());
+  }
+}
+
+TEST_F(DBBasicTest, BestEffortsRecoveryTryMultipleManifests) {
+  Options options = CurrentOptions();
+  options.env = env_;
+  DestroyAndReopen(options);
+  ASSERT_OK(Put("foo", "value0"));
+  ASSERT_OK(Flush());
+  Close();
+  {
+    // Hack by adding a new MANIFEST with high file number
+    std::string garbage(10, '\0');
+    ASSERT_OK(WriteStringToFile(env_, garbage, dbname_ + "/MANIFEST-001000",
+                                /*should_sync=*/true));
+  }
+  {
+    // Hack by adding a corrupted SST not referenced by any MANIFEST
+    std::string garbage(10, '\0');
+    ASSERT_OK(WriteStringToFile(env_, garbage, dbname_ + "/001001.sst",
+                                /*should_sync=*/true));
+  }
+
+  options.best_efforts_recovery = true;
+
+  Reopen(options);
+  ASSERT_OK(Put("bar", "value"));
+}
+
+TEST_F(DBBasicTest, RecoverWithNoCurrentFile) {
+  Options options = CurrentOptions();
+  options.env = env_;
+  DestroyAndReopen(options);
+  CreateAndReopenWithCF({"pikachu"}, options);
+  options.best_efforts_recovery = true;
+  ReopenWithColumnFamilies({kDefaultColumnFamilyName, "pikachu"}, options);
+  ASSERT_EQ(2, handles_.size());
+  ASSERT_OK(Put("foo", "value"));
+  ASSERT_OK(Put(1, "bar", "value"));
+  ASSERT_OK(Flush());
+  ASSERT_OK(Flush(1));
+  Close();
+  ASSERT_OK(env_->DeleteFile(CurrentFileName(dbname_)));
+  ReopenWithColumnFamilies({kDefaultColumnFamilyName, "pikachu"}, options);
+  std::vector<std::string> cf_names;
+  ASSERT_OK(DB::ListColumnFamilies(DBOptions(options), dbname_, &cf_names));
+  ASSERT_EQ(2, cf_names.size());
+  for (const auto& name : cf_names) {
+    ASSERT_TRUE(name == kDefaultColumnFamilyName || name == "pikachu");
+  }
+}
+
+TEST_F(DBBasicTest, RecoverWithNoManifest) {
+  Options options = CurrentOptions();
+  options.env = env_;
+  DestroyAndReopen(options);
+  ASSERT_OK(Put("foo", "value"));
+  ASSERT_OK(Flush());
+  Close();
+  {
+    // Delete all MANIFEST.
+    std::vector<std::string> files;
+    ASSERT_OK(env_->GetChildren(dbname_, &files));
+    for (const auto& file : files) {
+      uint64_t number = 0;
+      FileType type = kWalFile;
+      if (ParseFileName(file, &number, &type) && type == kDescriptorFile) {
+        ASSERT_OK(env_->DeleteFile(dbname_ + "/" + file));
+      }
+    }
+  }
+  options.best_efforts_recovery = true;
+  options.create_if_missing = false;
+  Status s = TryReopen(options);
+  ASSERT_TRUE(s.IsInvalidArgument());
+  options.create_if_missing = true;
+  Reopen(options);
+  // Since no MANIFEST exists, best-efforts recovery creates a new, empty db.
+  ASSERT_EQ("NOT_FOUND", Get("foo"));
+}
+
+TEST_F(DBBasicTest, SkipWALIfMissingTableFiles) {
+  Options options = CurrentOptions();
+  DestroyAndReopen(options);
+  TableFileListener* listener = new TableFileListener();
+  options.listeners.emplace_back(listener);
+  CreateAndReopenWithCF({"pikachu"}, options);
+  std::vector<std::string> kAllCfNames = {kDefaultColumnFamilyName, "pikachu"};
+  size_t num_cfs = handles_.size();
+  ASSERT_EQ(2, num_cfs);
+  for (int cf = 0; cf < static_cast<int>(kAllCfNames.size()); ++cf) {
+    ASSERT_OK(Put(cf, "a", "0_value"));
+    ASSERT_OK(Flush(cf));
+    ASSERT_OK(Put(cf, "b", "0_value"));
+  }
+  // Delete files
+  for (size_t i = 0; i < kAllCfNames.size(); ++i) {
+    std::vector<std::string>& files = listener->GetFiles(kAllCfNames[i]);
+    ASSERT_EQ(1, files.size());
+    for (int j = static_cast<int>(files.size() - 1); j >= static_cast<int>(i);
+         --j) {
+      ASSERT_OK(env_->DeleteFile(files[j]));
+    }
+  }
+  options.best_efforts_recovery = true;
+  ReopenWithColumnFamilies(kAllCfNames, options);
+  // Verify WAL is not applied
+  ReadOptions read_opts;
+  read_opts.total_order_seek = true;
+  std::unique_ptr<Iterator> iter(db_->NewIterator(read_opts, handles_[0]));
+  iter->SeekToFirst();
+  ASSERT_FALSE(iter->Valid());
+  ASSERT_OK(iter->status());
+  iter.reset(db_->NewIterator(read_opts, handles_[1]));
+  iter->SeekToFirst();
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ("a", iter->key());
+  iter->Next();
+  ASSERT_FALSE(iter->Valid());
+  ASSERT_OK(iter->status());
+}
+
+TEST_F(DBBasicTest, DisableTrackWal) {
+  // If WAL tracking was enabled, and then disabled during reopen,
+  // the previously tracked WALs should be removed from MANIFEST.
+
+  Options options = CurrentOptions();
+  options.track_and_verify_wals_in_manifest = true;
+  // extremely small write buffer size,
+  // so that new WALs are created more frequently.
+  options.write_buffer_size = 100;
+  options.env = env_;
+  DestroyAndReopen(options);
+  for (int i = 0; i < 100; i++) {
+    ASSERT_OK(Put("foo" + std::to_string(i), "value" + std::to_string(i)));
+  }
+  ASSERT_OK(dbfull()->TEST_SwitchMemtable());
+  ASSERT_OK(db_->SyncWAL());
+  // Some WALs are tracked.
+  ASSERT_FALSE(dbfull()->GetVersionSet()->GetWalSet().GetWals().empty());
+  Close();
+
+  // Disable WAL tracking.
+  options.track_and_verify_wals_in_manifest = false;
+  options.create_if_missing = false;
+  ASSERT_OK(TryReopen(options));
+  // Previously tracked WALs are cleared.
+  ASSERT_TRUE(dbfull()->GetVersionSet()->GetWalSet().GetWals().empty());
+  Close();
+
+  // Re-enable WAL tracking again.
+  options.track_and_verify_wals_in_manifest = true;
+  options.create_if_missing = false;
+  ASSERT_OK(TryReopen(options));
+  ASSERT_TRUE(dbfull()->GetVersionSet()->GetWalSet().GetWals().empty());
+  Close();
+}
+#endif  // !ROCKSDB_LITE
+
+TEST_F(DBBasicTest, ManifestChecksumMismatch) {
+  Options options = CurrentOptions();
+  DestroyAndReopen(options);
+  ASSERT_OK(Put("bar", "value"));
+  ASSERT_OK(Flush());
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  SyncPoint::GetInstance()->SetCallBack(
+      "LogWriter::EmitPhysicalRecord:BeforeEncodeChecksum", [&](void* arg) {
+        auto* crc = reinterpret_cast<uint32_t*>(arg);
+        *crc = *crc + 1;
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  WriteOptions write_opts;
+  write_opts.disableWAL = true;
+  Status s = db_->Put(write_opts, "foo", "value");
+  ASSERT_OK(s);
+  ASSERT_OK(Flush());
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  ASSERT_OK(Put("foo", "value1"));
+  ASSERT_OK(Flush());
+  s = TryReopen(options);
+  ASSERT_TRUE(s.IsCorruption());
+}
+
+TEST_F(DBBasicTest, ConcurrentlyCloseDB) {
+  Options options = CurrentOptions();
+  DestroyAndReopen(options);
+  std::vector<std::thread> workers;
+  for (int i = 0; i < 10; i++) {
+    workers.push_back(std::thread([&]() {
+      auto s = db_->Close();
+      ASSERT_OK(s);
+    }));
+  }
+  for (auto& w : workers) {
+    w.join();
+  }
+}
+
+#ifndef ROCKSDB_LITE
+class DBBasicTestTrackWal : public DBTestBase,
+                            public testing::WithParamInterface<bool> {
+ public:
+  DBBasicTestTrackWal()
+      : DBTestBase("db_basic_test_track_wal", /*env_do_fsync=*/false) {}
+
+  int CountWalFiles() {
+    VectorLogPtr log_files;
+    EXPECT_OK(dbfull()->GetSortedWalFiles(log_files));
+    return static_cast<int>(log_files.size());
+  };
+};
+
+TEST_P(DBBasicTestTrackWal, DoNotTrackObsoleteWal) {
+  // If a WAL becomes obsolete after flushing, but is not deleted from disk yet,
+  // then if SyncWAL is called afterwards, the obsolete WAL should not be
+  // tracked in MANIFEST.
+
+  Options options = CurrentOptions();
+  options.create_if_missing = true;
+  options.track_and_verify_wals_in_manifest = true;
+  options.atomic_flush = GetParam();
+
+  DestroyAndReopen(options);
+  CreateAndReopenWithCF({"cf"}, options);
+  ASSERT_EQ(handles_.size(), 2);  // default, cf
+  // Do not delete WALs.
+  ASSERT_OK(db_->DisableFileDeletions());
+  constexpr int n = 10;
+  std::vector<std::unique_ptr<LogFile>> wals(n);
+  for (size_t i = 0; i < n; i++) {
+    // Generate a new WAL for each key-value.
+    const int cf = i % 2;
+    ASSERT_OK(db_->GetCurrentWalFile(&wals[i]));
+    ASSERT_OK(Put(cf, "k" + std::to_string(i), "v" + std::to_string(i)));
+    ASSERT_OK(Flush({0, 1}));
+  }
+  ASSERT_EQ(CountWalFiles(), n);
+  // Since all WALs are obsolete, no WAL should be tracked in MANIFEST.
+  ASSERT_OK(db_->SyncWAL());
+
+  // Manually delete all WALs.
+  Close();
+  for (const auto& wal : wals) {
+    ASSERT_OK(env_->DeleteFile(LogFileName(dbname_, wal->LogNumber())));
+  }
+
+  // If SyncWAL tracks the obsolete WALs in MANIFEST,
+  // reopen will fail because the WALs are missing from disk.
+  ASSERT_OK(TryReopenWithColumnFamilies({"default", "cf"}, options));
+  Destroy(options);
+}
+
+INSTANTIATE_TEST_CASE_P(DBBasicTestTrackWal, DBBasicTestTrackWal,
+                        testing::Bool());
+#endif  // ROCKSDB_LITE
+
+class DBBasicTestMultiGet : public DBTestBase {
+ public:
+  DBBasicTestMultiGet(std::string test_dir, int num_cfs, bool compressed_cache,
+                      bool uncompressed_cache, bool _compression_enabled,
+                      bool _fill_cache, uint32_t compression_parallel_threads)
+      : DBTestBase(test_dir, /*env_do_fsync=*/false) {
+    compression_enabled_ = _compression_enabled;
+    fill_cache_ = _fill_cache;
+
+    if (compressed_cache) {
+      std::shared_ptr<Cache> cache = NewLRUCache(1048576);
+      compressed_cache_ = std::make_shared<MyBlockCache>(cache);
+    }
+    if (uncompressed_cache) {
+      std::shared_ptr<Cache> cache = NewLRUCache(1048576);
+      uncompressed_cache_ = std::make_shared<MyBlockCache>(cache);
+    }
+
+    env_->count_random_reads_ = true;
+
+    Options options = CurrentOptions();
+    Random rnd(301);
+    BlockBasedTableOptions table_options;
+
+#ifndef ROCKSDB_LITE
+    if (compression_enabled_) {
+      std::vector<CompressionType> compression_types;
+      compression_types = GetSupportedCompressions();
+      // Not every platform may have compression libraries available, so
+      // dynamically pick based on what's available
+      CompressionType tmp_type = kNoCompression;
+      for (auto c_type : compression_types) {
+        if (c_type != kNoCompression) {
+          tmp_type = c_type;
+          break;
+        }
+      }
+      if (tmp_type != kNoCompression) {
+        options.compression = tmp_type;
+      } else {
+        compression_enabled_ = false;
+      }
+    }
+#else
+    // GetSupportedCompressions() is not available in LITE build
+    if (!Snappy_Supported()) {
+      compression_enabled_ = false;
+    }
+#endif  // ROCKSDB_LITE
+
+    table_options.block_cache = uncompressed_cache_;
+    if (table_options.block_cache == nullptr) {
+      table_options.no_block_cache = true;
+    } else {
+      table_options.pin_l0_filter_and_index_blocks_in_cache = true;
+    }
+    table_options.block_cache_compressed = compressed_cache_;
+    table_options.flush_block_policy_factory.reset(
+        new MyFlushBlockPolicyFactory());
+    options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+    if (!compression_enabled_) {
+      options.compression = kNoCompression;
+    } else {
+      options.compression_opts.parallel_threads = compression_parallel_threads;
+    }
+    options_ = options;
+    Reopen(options);
+
+    if (num_cfs > 1) {
+      for (int cf = 0; cf < num_cfs; ++cf) {
+        cf_names_.emplace_back("cf" + std::to_string(cf));
+      }
+      CreateColumnFamilies(cf_names_, options);
+      cf_names_.emplace_back("default");
+    }
+
+    std::string zero_str(128, '\0');
+    for (int cf = 0; cf < num_cfs; ++cf) {
+      for (int i = 0; i < 100; ++i) {
+        // Make the value compressible. A purely random string doesn't compress
+        // and the resultant data block will not be compressed
+        values_.emplace_back(rnd.RandomString(128) + zero_str);
+        assert(((num_cfs == 1) ? Put(Key(i), values_[i])
+                               : Put(cf, Key(i), values_[i])) == Status::OK());
+      }
+      if (num_cfs == 1) {
+        EXPECT_OK(Flush());
+      } else {
+        EXPECT_OK(dbfull()->Flush(FlushOptions(), handles_[cf]));
+      }
+
+      for (int i = 0; i < 100; ++i) {
+        // block cannot gain space by compression
+        uncompressable_values_.emplace_back(rnd.RandomString(256) + '\0');
+        std::string tmp_key = "a" + Key(i);
+        assert(((num_cfs == 1) ? Put(tmp_key, uncompressable_values_[i])
+                               : Put(cf, tmp_key, uncompressable_values_[i])) ==
+               Status::OK());
+      }
+      if (num_cfs == 1) {
+        EXPECT_OK(Flush());
+      } else {
+        EXPECT_OK(dbfull()->Flush(FlushOptions(), handles_[cf]));
+      }
+    }
+    // Clear compressed cache, which is always pre-populated
+    if (compressed_cache_) {
+      compressed_cache_->SetCapacity(0);
+      compressed_cache_->SetCapacity(1048576);
+    }
+  }
+
+  bool CheckValue(int i, const std::string& value) {
+    if (values_[i].compare(value) == 0) {
+      return true;
+    }
+    return false;
+  }
+
+  bool CheckUncompressableValue(int i, const std::string& value) {
+    if (uncompressable_values_[i].compare(value) == 0) {
+      return true;
+    }
+    return false;
+  }
+
+  const std::vector<std::string>& GetCFNames() const { return cf_names_; }
+
+  int num_lookups() { return uncompressed_cache_->num_lookups(); }
+  int num_found() { return uncompressed_cache_->num_found(); }
+  int num_inserts() { return uncompressed_cache_->num_inserts(); }
+
+  int num_lookups_compressed() { return compressed_cache_->num_lookups(); }
+  int num_found_compressed() { return compressed_cache_->num_found(); }
+  int num_inserts_compressed() { return compressed_cache_->num_inserts(); }
+
+  bool fill_cache() { return fill_cache_; }
+  bool compression_enabled() { return compression_enabled_; }
+  bool has_compressed_cache() { return compressed_cache_ != nullptr; }
+  bool has_uncompressed_cache() { return uncompressed_cache_ != nullptr; }
+  Options get_options() { return options_; }
+
+  static void SetUpTestCase() {}
+  static void TearDownTestCase() {}
+
+ protected:
+  class MyFlushBlockPolicyFactory : public FlushBlockPolicyFactory {
+   public:
+    MyFlushBlockPolicyFactory() {}
+
+    virtual const char* Name() const override {
+      return "MyFlushBlockPolicyFactory";
+    }
+
+    virtual FlushBlockPolicy* NewFlushBlockPolicy(
+        const BlockBasedTableOptions& /*table_options*/,
+        const BlockBuilder& data_block_builder) const override {
+      return new MyFlushBlockPolicy(data_block_builder);
+    }
+  };
+
+  class MyFlushBlockPolicy : public FlushBlockPolicy {
+   public:
+    explicit MyFlushBlockPolicy(const BlockBuilder& data_block_builder)
+        : num_keys_(0), data_block_builder_(data_block_builder) {}
+
+    bool Update(const Slice& /*key*/, const Slice& /*value*/) override {
+      if (data_block_builder_.empty()) {
+        // First key in this block
+        num_keys_ = 1;
+        return false;
+      }
+      // Flush every 10 keys
+      if (num_keys_ == 10) {
+        num_keys_ = 1;
+        return true;
+      }
+      num_keys_++;
+      return false;
+    }
+
+   private:
+    int num_keys_;
+    const BlockBuilder& data_block_builder_;
+  };
+
+  class MyBlockCache : public CacheWrapper {
+   public:
+    explicit MyBlockCache(std::shared_ptr<Cache> target)
+        : CacheWrapper(target),
+          num_lookups_(0),
+          num_found_(0),
+          num_inserts_(0) {}
+
+    const char* Name() const override { return "MyBlockCache"; }
+
+    using Cache::Insert;
+    Status Insert(const Slice& key, void* value, size_t charge,
+                  void (*deleter)(const Slice& key, void* value),
+                  Handle** handle = nullptr,
+                  Priority priority = Priority::LOW) override {
+      num_inserts_++;
+      return target_->Insert(key, value, charge, deleter, handle, priority);
+    }
+
+    using Cache::Lookup;
+    Handle* Lookup(const Slice& key, Statistics* stats = nullptr) override {
+      num_lookups_++;
+      Handle* handle = target_->Lookup(key, stats);
+      if (handle != nullptr) {
+        num_found_++;
+      }
+      return handle;
+    }
+    int num_lookups() { return num_lookups_; }
+
+    int num_found() { return num_found_; }
+
+    int num_inserts() { return num_inserts_; }
+
+   private:
+    int num_lookups_;
+    int num_found_;
+    int num_inserts_;
+  };
+
+  std::shared_ptr<MyBlockCache> compressed_cache_;
+  std::shared_ptr<MyBlockCache> uncompressed_cache_;
+  Options options_;
+  bool compression_enabled_;
+  std::vector<std::string> values_;
+  std::vector<std::string> uncompressable_values_;
+  bool fill_cache_;
+  std::vector<std::string> cf_names_;
+};
+
+class DBBasicTestWithParallelIO
+    : public DBBasicTestMultiGet,
+      public testing::WithParamInterface<
+          std::tuple<bool, bool, bool, bool, uint32_t>> {
+ public:
+  DBBasicTestWithParallelIO()
+      : DBBasicTestMultiGet("/db_basic_test_with_parallel_io", 1,
+                            std::get<0>(GetParam()), std::get<1>(GetParam()),
+                            std::get<2>(GetParam()), std::get<3>(GetParam()),
+                            std::get<4>(GetParam())) {}
+};
+
+TEST_P(DBBasicTestWithParallelIO, MultiGet) {
+  std::vector<std::string> key_data(10);
+  std::vector<Slice> keys;
+  // We cannot resize a PinnableSlice vector, so just set initial size to
+  // largest we think we will need
+  std::vector<PinnableSlice> values(10);
+  std::vector<Status> statuses;
+  ReadOptions ro;
+  ro.fill_cache = fill_cache();
+
+  // Warm up the cache first
+  key_data.emplace_back(Key(0));
+  keys.emplace_back(Slice(key_data.back()));
+  key_data.emplace_back(Key(50));
+  keys.emplace_back(Slice(key_data.back()));
+  statuses.resize(keys.size());
+
+  dbfull()->MultiGet(ro, dbfull()->DefaultColumnFamily(), keys.size(),
+                     keys.data(), values.data(), statuses.data(), true);
+  ASSERT_TRUE(CheckValue(0, values[0].ToString()));
+  ASSERT_TRUE(CheckValue(50, values[1].ToString()));
+
+  int random_reads = env_->random_read_counter_.Read();
+  key_data[0] = Key(1);
+  key_data[1] = Key(51);
+  keys[0] = Slice(key_data[0]);
+  keys[1] = Slice(key_data[1]);
+  values[0].Reset();
+  values[1].Reset();
+  dbfull()->MultiGet(ro, dbfull()->DefaultColumnFamily(), keys.size(),
+                     keys.data(), values.data(), statuses.data(), true);
+  ASSERT_TRUE(CheckValue(1, values[0].ToString()));
+  ASSERT_TRUE(CheckValue(51, values[1].ToString()));
+
+  bool read_from_cache = false;
+  if (fill_cache()) {
+    if (has_uncompressed_cache()) {
+      read_from_cache = true;
+    } else if (has_compressed_cache() && compression_enabled()) {
+      read_from_cache = true;
+    }
+  }
+
+  int expected_reads = random_reads + (read_from_cache ? 0 : 2);
+  ASSERT_EQ(env_->random_read_counter_.Read(), expected_reads);
+
+  keys.resize(10);
+  statuses.resize(10);
+  std::vector<int> key_ints{1, 2, 15, 16, 55, 81, 82, 83, 84, 85};
+  for (size_t i = 0; i < key_ints.size(); ++i) {
+    key_data[i] = Key(key_ints[i]);
+    keys[i] = Slice(key_data[i]);
+    statuses[i] = Status::OK();
+    values[i].Reset();
+  }
+  dbfull()->MultiGet(ro, dbfull()->DefaultColumnFamily(), keys.size(),
+                     keys.data(), values.data(), statuses.data(), true);
+  for (size_t i = 0; i < key_ints.size(); ++i) {
+    ASSERT_OK(statuses[i]);
+    ASSERT_TRUE(CheckValue(key_ints[i], values[i].ToString()));
+  }
+  if (compression_enabled() && !has_compressed_cache()) {
+    expected_reads += (read_from_cache ? 2 : 3);
+  } else {
+    expected_reads += (read_from_cache ? 2 : 4);
+  }
+  ASSERT_EQ(env_->random_read_counter_.Read(), expected_reads);
+
+  keys.resize(10);
+  statuses.resize(10);
+  std::vector<int> key_uncmp{1, 2, 15, 16, 55, 81, 82, 83, 84, 85};
+  for (size_t i = 0; i < key_uncmp.size(); ++i) {
+    key_data[i] = "a" + Key(key_uncmp[i]);
+    keys[i] = Slice(key_data[i]);
+    statuses[i] = Status::OK();
+    values[i].Reset();
+  }
+  dbfull()->MultiGet(ro, dbfull()->DefaultColumnFamily(), keys.size(),
+                     keys.data(), values.data(), statuses.data(), true);
+  for (size_t i = 0; i < key_uncmp.size(); ++i) {
+    ASSERT_OK(statuses[i]);
+    ASSERT_TRUE(CheckUncompressableValue(key_uncmp[i], values[i].ToString()));
+  }
+  if (compression_enabled() && !has_compressed_cache()) {
+    expected_reads += (read_from_cache ? 3 : 3);
+  } else {
+    expected_reads += (read_from_cache ? 4 : 4);
+  }
+  ASSERT_EQ(env_->random_read_counter_.Read(), expected_reads);
+
+  keys.resize(5);
+  statuses.resize(5);
+  std::vector<int> key_tr{1, 2, 15, 16, 55};
+  for (size_t i = 0; i < key_tr.size(); ++i) {
+    key_data[i] = "a" + Key(key_tr[i]);
+    keys[i] = Slice(key_data[i]);
+    statuses[i] = Status::OK();
+    values[i].Reset();
+  }
+  dbfull()->MultiGet(ro, dbfull()->DefaultColumnFamily(), keys.size(),
+                     keys.data(), values.data(), statuses.data(), true);
+  for (size_t i = 0; i < key_tr.size(); ++i) {
+    ASSERT_OK(statuses[i]);
+    ASSERT_TRUE(CheckUncompressableValue(key_tr[i], values[i].ToString()));
+  }
+  if (compression_enabled() && !has_compressed_cache()) {
+    expected_reads += (read_from_cache ? 0 : 2);
+    ASSERT_EQ(env_->random_read_counter_.Read(), expected_reads);
+  } else {
+    if (has_uncompressed_cache()) {
+      expected_reads += (read_from_cache ? 0 : 3);
+      ASSERT_EQ(env_->random_read_counter_.Read(), expected_reads);
+    } else {
+      // A rare case, even we enable the block compression but some of data
+      // blocks are not compressed due to content. If user only enable the
+      // compressed cache, the uncompressed blocks will not tbe cached, and
+      // block reads will be triggered. The number of reads is related to
+      // the compression algorithm.
+      ASSERT_TRUE(env_->random_read_counter_.Read() >= expected_reads);
+    }
+  }
+}
+
+#ifndef ROCKSDB_LITE
+TEST_P(DBBasicTestWithParallelIO, MultiGetDirectIO) {
+  class FakeDirectIOEnv : public EnvWrapper {
+    class FakeDirectIOSequentialFile;
+    class FakeDirectIORandomAccessFile;
+
+   public:
+    FakeDirectIOEnv(Env* env) : EnvWrapper(env) {}
+    static const char* kClassName() { return "FakeDirectIOEnv"; }
+    const char* Name() const override { return kClassName(); }
+
+    Status NewRandomAccessFile(const std::string& fname,
+                               std::unique_ptr<RandomAccessFile>* result,
+                               const EnvOptions& options) override {
+      std::unique_ptr<RandomAccessFile> file;
+      assert(options.use_direct_reads);
+      EnvOptions opts = options;
+      opts.use_direct_reads = false;
+      Status s = target()->NewRandomAccessFile(fname, &file, opts);
+      if (!s.ok()) {
+        return s;
+      }
+      result->reset(new FakeDirectIORandomAccessFile(std::move(file)));
+      return s;
+    }
+
+   private:
+    class FakeDirectIOSequentialFile : public SequentialFileWrapper {
+     public:
+      FakeDirectIOSequentialFile(std::unique_ptr<SequentialFile>&& file)
+          : SequentialFileWrapper(file.get()), file_(std::move(file)) {}
+      ~FakeDirectIOSequentialFile() {}
+
+      bool use_direct_io() const override { return true; }
+      size_t GetRequiredBufferAlignment() const override { return 1; }
+
+     private:
+      std::unique_ptr<SequentialFile> file_;
+    };
+
+    class FakeDirectIORandomAccessFile : public RandomAccessFileWrapper {
+     public:
+      FakeDirectIORandomAccessFile(std::unique_ptr<RandomAccessFile>&& file)
+          : RandomAccessFileWrapper(file.get()), file_(std::move(file)) {}
+      ~FakeDirectIORandomAccessFile() {}
+
+      bool use_direct_io() const override { return true; }
+      size_t GetRequiredBufferAlignment() const override { return 1; }
+
+     private:
+      std::unique_ptr<RandomAccessFile> file_;
+    };
+  };
+
+  std::unique_ptr<FakeDirectIOEnv> env(new FakeDirectIOEnv(env_));
+  Options opts = get_options();
+  opts.env = env.get();
+  opts.use_direct_reads = true;
+  Reopen(opts);
+
+  std::vector<std::string> key_data(10);
+  std::vector<Slice> keys;
+  // We cannot resize a PinnableSlice vector, so just set initial size to
+  // largest we think we will need
+  std::vector<PinnableSlice> values(10);
+  std::vector<Status> statuses;
+  ReadOptions ro;
+  ro.fill_cache = fill_cache();
+
+  // Warm up the cache first
+  key_data.emplace_back(Key(0));
+  keys.emplace_back(Slice(key_data.back()));
+  key_data.emplace_back(Key(50));
+  keys.emplace_back(Slice(key_data.back()));
+  statuses.resize(keys.size());
+
+  dbfull()->MultiGet(ro, dbfull()->DefaultColumnFamily(), keys.size(),
+                     keys.data(), values.data(), statuses.data(), true);
+  ASSERT_TRUE(CheckValue(0, values[0].ToString()));
+  ASSERT_TRUE(CheckValue(50, values[1].ToString()));
+
+  int random_reads = env_->random_read_counter_.Read();
+  key_data[0] = Key(1);
+  key_data[1] = Key(51);
+  keys[0] = Slice(key_data[0]);
+  keys[1] = Slice(key_data[1]);
+  values[0].Reset();
+  values[1].Reset();
+  if (uncompressed_cache_) {
+    uncompressed_cache_->SetCapacity(0);
+    uncompressed_cache_->SetCapacity(1048576);
+  }
+  dbfull()->MultiGet(ro, dbfull()->DefaultColumnFamily(), keys.size(),
+                     keys.data(), values.data(), statuses.data(), true);
+  ASSERT_TRUE(CheckValue(1, values[0].ToString()));
+  ASSERT_TRUE(CheckValue(51, values[1].ToString()));
+
+  bool read_from_cache = false;
+  if (fill_cache()) {
+    if (has_uncompressed_cache()) {
+      read_from_cache = true;
+    } else if (has_compressed_cache() && compression_enabled()) {
+      read_from_cache = true;
+    }
+  }
+
+  int expected_reads = random_reads;
+  if (!compression_enabled() || !has_compressed_cache()) {
+    expected_reads += 2;
+  } else {
+    expected_reads += (read_from_cache ? 0 : 2);
+  }
+  if (env_->random_read_counter_.Read() != expected_reads) {
+    ASSERT_EQ(env_->random_read_counter_.Read(), expected_reads);
+  }
+  Close();
+}
+#endif  // ROCKSDB_LITE
+
+TEST_P(DBBasicTestWithParallelIO, MultiGetWithChecksumMismatch) {
+  std::vector<std::string> key_data(10);
+  std::vector<Slice> keys;
+  // We cannot resize a PinnableSlice vector, so just set initial size to
+  // largest we think we will need
+  std::vector<PinnableSlice> values(10);
+  std::vector<Status> statuses;
+  int read_count = 0;
+  ReadOptions ro;
+  ro.fill_cache = fill_cache();
+
+  SyncPoint::GetInstance()->SetCallBack(
+      "RetrieveMultipleBlocks:VerifyChecksum", [&](void* status) {
+        Status* s = static_cast<Status*>(status);
+        read_count++;
+        if (read_count == 2) {
+          *s = Status::Corruption();
+        }
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  // Warm up the cache first
+  key_data.emplace_back(Key(0));
+  keys.emplace_back(Slice(key_data.back()));
+  key_data.emplace_back(Key(50));
+  keys.emplace_back(Slice(key_data.back()));
+  statuses.resize(keys.size());
+
+  dbfull()->MultiGet(ro, dbfull()->DefaultColumnFamily(), keys.size(),
+                     keys.data(), values.data(), statuses.data(), true);
+  ASSERT_TRUE(CheckValue(0, values[0].ToString()));
+  // ASSERT_TRUE(CheckValue(50, values[1].ToString()));
+  ASSERT_EQ(statuses[0], Status::OK());
+  ASSERT_EQ(statuses[1], Status::Corruption());
+
+  SyncPoint::GetInstance()->DisableProcessing();
+}
+
+TEST_P(DBBasicTestWithParallelIO, MultiGetWithMissingFile) {
+  std::vector<std::string> key_data(10);
+  std::vector<Slice> keys;
+  // We cannot resize a PinnableSlice vector, so just set initial size to
+  // largest we think we will need
+  std::vector<PinnableSlice> values(10);
+  std::vector<Status> statuses;
+  ReadOptions ro;
+  ro.fill_cache = fill_cache();
+
+  SyncPoint::GetInstance()->SetCallBack(
+      "TableCache::MultiGet:FindTable", [&](void* status) {
+        Status* s = static_cast<Status*>(status);
+        *s = Status::IOError();
+      });
+  // DB open will create table readers unless we reduce the table cache
+  // capacity.
+  // SanitizeOptions will set max_open_files to minimum of 20. Table cache
+  // is allocated with max_open_files - 10 as capacity. So override
+  // max_open_files to 11 so table cache capacity will become 1. This will
+  // prevent file open during DB open and force the file to be opened
+  // during MultiGet
+  SyncPoint::GetInstance()->SetCallBack(
+      "SanitizeOptions::AfterChangeMaxOpenFiles", [&](void* arg) {
+        int* max_open_files = (int*)arg;
+        *max_open_files = 11;
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  Reopen(CurrentOptions());
+
+  // Warm up the cache first
+  key_data.emplace_back(Key(0));
+  keys.emplace_back(Slice(key_data.back()));
+  key_data.emplace_back(Key(50));
+  keys.emplace_back(Slice(key_data.back()));
+  statuses.resize(keys.size());
+
+  dbfull()->MultiGet(ro, dbfull()->DefaultColumnFamily(), keys.size(),
+                     keys.data(), values.data(), statuses.data(), true);
+  ASSERT_EQ(statuses[0], Status::IOError());
+  ASSERT_EQ(statuses[1], Status::IOError());
+
+  SyncPoint::GetInstance()->DisableProcessing();
+}
+
+INSTANTIATE_TEST_CASE_P(ParallelIO, DBBasicTestWithParallelIO,
+                        // Params are as follows -
+                        // Param 0 - Compressed cache enabled
+                        // Param 1 - Uncompressed cache enabled
+                        // Param 2 - Data compression enabled
+                        // Param 3 - ReadOptions::fill_cache
+                        // Param 4 - CompressionOptions::parallel_threads
+                        ::testing::Combine(::testing::Bool(), ::testing::Bool(),
+                                           ::testing::Bool(), ::testing::Bool(),
+                                           ::testing::Values(1, 4)));
+
+// Forward declaration
+class DeadlineFS;
+
+class DeadlineRandomAccessFile : public FSRandomAccessFileOwnerWrapper {
+ public:
+  DeadlineRandomAccessFile(DeadlineFS& fs,
+                           std::unique_ptr<FSRandomAccessFile>& file)
+      : FSRandomAccessFileOwnerWrapper(std::move(file)), fs_(fs) {}
+
+  IOStatus Read(uint64_t offset, size_t len, const IOOptions& opts,
+                Slice* result, char* scratch,
+                IODebugContext* dbg) const override;
+
+  IOStatus MultiRead(FSReadRequest* reqs, size_t num_reqs,
+                     const IOOptions& options, IODebugContext* dbg) override;
+
+  IOStatus ReadAsync(FSReadRequest& req, const IOOptions& opts,
+                     std::function<void(const FSReadRequest&, void*)> cb,
+                     void* cb_arg, void** io_handle, IOHandleDeleter* del_fn,
+                     IODebugContext* dbg) override;
+
+ private:
+  DeadlineFS& fs_;
+  std::unique_ptr<FSRandomAccessFile> file_;
+};
+
+class DeadlineFS : public FileSystemWrapper {
+ public:
+  // The error_on_delay parameter specifies whether a IOStatus::TimedOut()
+  // status should be returned after delaying the IO to exceed the timeout,
+  // or to simply delay but return success anyway. The latter mimics the
+  // behavior of PosixFileSystem, which does not enforce any timeout
+  explicit DeadlineFS(SpecialEnv* env, bool error_on_delay)
+      : FileSystemWrapper(env->GetFileSystem()),
+        deadline_(std::chrono::microseconds::zero()),
+        io_timeout_(std::chrono::microseconds::zero()),
+        env_(env),
+        timedout_(false),
+        ignore_deadline_(false),
+        error_on_delay_(error_on_delay) {}
+
+  static const char* kClassName() { return "DeadlineFileSystem"; }
+  const char* Name() const override { return kClassName(); }
+
+  IOStatus NewRandomAccessFile(const std::string& fname,
+                               const FileOptions& opts,
+                               std::unique_ptr<FSRandomAccessFile>* result,
+                               IODebugContext* dbg) override {
+    std::unique_ptr<FSRandomAccessFile> file;
+    IOStatus s = target()->NewRandomAccessFile(fname, opts, &file, dbg);
+    EXPECT_OK(s);
+    result->reset(new DeadlineRandomAccessFile(*this, file));
+
+    const std::chrono::microseconds deadline = GetDeadline();
+    const std::chrono::microseconds io_timeout = GetIOTimeout();
+    if (deadline.count() || io_timeout.count()) {
+      AssertDeadline(deadline, io_timeout, opts.io_options);
+    }
+    return ShouldDelay(opts.io_options);
+  }
+
+  // Set a vector of {IO counter, delay in microseconds, return status} tuples
+  // that control when to inject a delay and duration of the delay
+  void SetDelayTrigger(const std::chrono::microseconds deadline,
+                       const std::chrono::microseconds io_timeout,
+                       const int trigger) {
+    delay_trigger_ = trigger;
+    io_count_ = 0;
+    deadline_ = deadline;
+    io_timeout_ = io_timeout;
+    timedout_ = false;
+  }
+
+  // Increment the IO counter and return a delay in microseconds
+  IOStatus ShouldDelay(const IOOptions& opts) {
+    if (timedout_) {
+      return IOStatus::TimedOut();
+    } else if (!deadline_.count() && !io_timeout_.count()) {
+      return IOStatus::OK();
+    }
+    if (!ignore_deadline_ && delay_trigger_ == io_count_++) {
+      env_->SleepForMicroseconds(static_cast<int>(opts.timeout.count() + 1));
+      timedout_ = true;
+      if (error_on_delay_) {
+        return IOStatus::TimedOut();
+      }
+    }
+    return IOStatus::OK();
+  }
+
+  const std::chrono::microseconds GetDeadline() {
+    return ignore_deadline_ ? std::chrono::microseconds::zero() : deadline_;
+  }
+
+  const std::chrono::microseconds GetIOTimeout() {
+    return ignore_deadline_ ? std::chrono::microseconds::zero() : io_timeout_;
+  }
+
+  bool TimedOut() { return timedout_; }
+
+  void IgnoreDeadline(bool ignore) { ignore_deadline_ = ignore; }
+
+  void AssertDeadline(const std::chrono::microseconds deadline,
+                      const std::chrono::microseconds io_timeout,
+                      const IOOptions& opts) const {
+    // Give a leeway of +- 10us as it can take some time for the Get/
+    // MultiGet call to reach here, in order to avoid false alarms
+    std::chrono::microseconds now =
+        std::chrono::microseconds(env_->NowMicros());
+    std::chrono::microseconds timeout;
+    if (deadline.count()) {
+      timeout = deadline - now;
+      if (io_timeout.count()) {
+        timeout = std::min(timeout, io_timeout);
+      }
+    } else {
+      timeout = io_timeout;
+    }
+    if (opts.timeout != timeout) {
+      ASSERT_EQ(timeout, opts.timeout);
+    }
+  }
+
+ private:
+  // The number of IOs to trigger the delay after
+  int delay_trigger_;
+  // Current IO count
+  int io_count_;
+  // ReadOptions deadline for the Get/MultiGet/Iterator
+  std::chrono::microseconds deadline_;
+  // ReadOptions io_timeout for the Get/MultiGet/Iterator
+  std::chrono::microseconds io_timeout_;
+  SpecialEnv* env_;
+  // Flag to indicate whether we injected a delay
+  bool timedout_;
+  // Temporarily ignore deadlines/timeouts
+  bool ignore_deadline_;
+  // Return IOStatus::TimedOut() or IOStatus::OK()
+  bool error_on_delay_;
+};
+
+IOStatus DeadlineRandomAccessFile::Read(uint64_t offset, size_t len,
+                                        const IOOptions& opts, Slice* result,
+                                        char* scratch,
+                                        IODebugContext* dbg) const {
+  const std::chrono::microseconds deadline = fs_.GetDeadline();
+  const std::chrono::microseconds io_timeout = fs_.GetIOTimeout();
+  IOStatus s;
+  if (deadline.count() || io_timeout.count()) {
+    fs_.AssertDeadline(deadline, io_timeout, opts);
+  }
+  if (s.ok()) {
+    s = FSRandomAccessFileWrapper::Read(offset, len, opts, result, scratch,
+                                        dbg);
+  }
+  if (s.ok()) {
+    s = fs_.ShouldDelay(opts);
+  }
+  return s;
+}
+
+IOStatus DeadlineRandomAccessFile::ReadAsync(
+    FSReadRequest& req, const IOOptions& opts,
+    std::function<void(const FSReadRequest&, void*)> cb, void* cb_arg,
+    void** io_handle, IOHandleDeleter* del_fn, IODebugContext* dbg) {
+  const std::chrono::microseconds deadline = fs_.GetDeadline();
+  const std::chrono::microseconds io_timeout = fs_.GetIOTimeout();
+  IOStatus s;
+  if (deadline.count() || io_timeout.count()) {
+    fs_.AssertDeadline(deadline, io_timeout, opts);
+  }
+  if (s.ok()) {
+    s = FSRandomAccessFileWrapper::ReadAsync(req, opts, cb, cb_arg, io_handle,
+                                             del_fn, dbg);
+  }
+  if (s.ok()) {
+    s = fs_.ShouldDelay(opts);
+  }
+  return s;
+}
+
+IOStatus DeadlineRandomAccessFile::MultiRead(FSReadRequest* reqs,
+                                             size_t num_reqs,
+                                             const IOOptions& options,
+                                             IODebugContext* dbg) {
+  const std::chrono::microseconds deadline = fs_.GetDeadline();
+  const std::chrono::microseconds io_timeout = fs_.GetIOTimeout();
+  IOStatus s;
+  if (deadline.count() || io_timeout.count()) {
+    fs_.AssertDeadline(deadline, io_timeout, options);
+  }
+  if (s.ok()) {
+    s = FSRandomAccessFileWrapper::MultiRead(reqs, num_reqs, options, dbg);
+  }
+  if (s.ok()) {
+    s = fs_.ShouldDelay(options);
+  }
+  return s;
+}
+
+// A test class for intercepting random reads and injecting artificial
+// delays. Used for testing the MultiGet deadline feature
+class DBBasicTestMultiGetDeadline : public DBBasicTestMultiGet,
+                                    public testing::WithParamInterface<bool> {
+ public:
+  DBBasicTestMultiGetDeadline()
+      : DBBasicTestMultiGet(
+            "db_basic_test_multiget_deadline" /*Test dir*/,
+            10 /*# of column families*/, false /*compressed cache enabled*/,
+            true /*uncompressed cache enabled*/, true /*compression enabled*/,
+            true /*ReadOptions.fill_cache*/,
+            1 /*# of parallel compression threads*/) {}
+
+  inline void CheckStatus(std::vector<Status>& statuses, size_t num_ok) {
+    for (size_t i = 0; i < statuses.size(); ++i) {
+      if (i < num_ok) {
+        EXPECT_OK(statuses[i]);
+      } else {
+        if (statuses[i] != Status::TimedOut()) {
+          EXPECT_EQ(statuses[i], Status::TimedOut());
+        }
+      }
+    }
+  }
+};
+
+TEST_P(DBBasicTestMultiGetDeadline, MultiGetDeadlineExceeded) {
+#ifndef USE_COROUTINES
+  if (GetParam()) {
+    ROCKSDB_GTEST_SKIP("This test requires coroutine support");
+    return;
+  }
+#endif  // USE_COROUTINES
+  std::shared_ptr<DeadlineFS> fs = std::make_shared<DeadlineFS>(env_, false);
+  std::unique_ptr<Env> env(new CompositeEnvWrapper(env_, fs));
+  Options options = CurrentOptions();
+
+  std::shared_ptr<Cache> cache = NewLRUCache(1048576);
+  BlockBasedTableOptions table_options;
+  table_options.block_cache = cache;
+  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+  options.env = env.get();
+  SetTimeElapseOnlySleepOnReopen(&options);
+  ReopenWithColumnFamilies(GetCFNames(), options);
+
+  // Test the non-batched version of MultiGet with multiple column
+  // families
+  std::vector<std::string> key_str;
+  size_t i;
+  for (i = 0; i < 5; ++i) {
+    key_str.emplace_back(Key(static_cast<int>(i)));
+  }
+  std::vector<ColumnFamilyHandle*> cfs(key_str.size());
+  ;
+  std::vector<Slice> keys(key_str.size());
+  std::vector<std::string> values(key_str.size());
+  for (i = 0; i < key_str.size(); ++i) {
+    cfs[i] = handles_[i];
+    keys[i] = Slice(key_str[i].data(), key_str[i].size());
+  }
+
+  ReadOptions ro;
+  ro.deadline = std::chrono::microseconds{env->NowMicros() + 10000};
+  ro.async_io = GetParam();
+  // Delay the first IO
+  fs->SetDelayTrigger(ro.deadline, ro.io_timeout, 0);
+
+  std::vector<Status> statuses = dbfull()->MultiGet(ro, cfs, keys, &values);
+  // The first key is successful because we check after the lookup, but
+  // subsequent keys fail due to deadline exceeded
+  CheckStatus(statuses, 1);
+
+  // Clear the cache
+  cache->SetCapacity(0);
+  cache->SetCapacity(1048576);
+  // Test non-batched Multiget with multiple column families and
+  // introducing an IO delay in one of the middle CFs
+  key_str.clear();
+  for (i = 0; i < 10; ++i) {
+    key_str.emplace_back(Key(static_cast<int>(i)));
+  }
+  cfs.resize(key_str.size());
+  keys.resize(key_str.size());
+  values.resize(key_str.size());
+  for (i = 0; i < key_str.size(); ++i) {
+    // 2 keys per CF
+    cfs[i] = handles_[i / 2];
+    keys[i] = Slice(key_str[i].data(), key_str[i].size());
+  }
+  ro.deadline = std::chrono::microseconds{env->NowMicros() + 10000};
+  fs->SetDelayTrigger(ro.deadline, ro.io_timeout, 1);
+  statuses = dbfull()->MultiGet(ro, cfs, keys, &values);
+  CheckStatus(statuses, 3);
+
+  // Test batched MultiGet with an IO delay in the first data block read.
+  // Both keys in the first CF should succeed as they're in the same data
+  // block and would form one batch, and we check for deadline between
+  // batches.
+  std::vector<PinnableSlice> pin_values(keys.size());
+  cache->SetCapacity(0);
+  cache->SetCapacity(1048576);
+  statuses.clear();
+  statuses.resize(keys.size());
+  ro.deadline = std::chrono::microseconds{env->NowMicros() + 10000};
+  fs->SetDelayTrigger(ro.deadline, ro.io_timeout, 0);
+  dbfull()->MultiGet(ro, keys.size(), cfs.data(), keys.data(),
+                     pin_values.data(), statuses.data());
+  CheckStatus(statuses, 2);
+
+  // Similar to the previous one, but an IO delay in the third CF data block
+  // read
+  for (PinnableSlice& value : pin_values) {
+    value.Reset();
+  }
+  cache->SetCapacity(0);
+  cache->SetCapacity(1048576);
+  statuses.clear();
+  statuses.resize(keys.size());
+  ro.deadline = std::chrono::microseconds{env->NowMicros() + 10000};
+  fs->SetDelayTrigger(ro.deadline, ro.io_timeout, 2);
+  dbfull()->MultiGet(ro, keys.size(), cfs.data(), keys.data(),
+                     pin_values.data(), statuses.data());
+  CheckStatus(statuses, 6);
+
+  // Similar to the previous one, but an IO delay in the last but one CF
+  for (PinnableSlice& value : pin_values) {
+    value.Reset();
+  }
+  cache->SetCapacity(0);
+  cache->SetCapacity(1048576);
+  statuses.clear();
+  statuses.resize(keys.size());
+  ro.deadline = std::chrono::microseconds{env->NowMicros() + 10000};
+  fs->SetDelayTrigger(ro.deadline, ro.io_timeout, 3);
+  dbfull()->MultiGet(ro, keys.size(), cfs.data(), keys.data(),
+                     pin_values.data(), statuses.data());
+  CheckStatus(statuses, 8);
+
+  // Test batched MultiGet with single CF and lots of keys. Inject delay
+  // into the second batch of keys. As each batch is 32, the first 64 keys,
+  // i.e first two batches, should succeed and the rest should time out
+  for (PinnableSlice& value : pin_values) {
+    value.Reset();
+  }
+  cache->SetCapacity(0);
+  cache->SetCapacity(1048576);
+  key_str.clear();
+  for (i = 0; i < 100; ++i) {
+    key_str.emplace_back(Key(static_cast<int>(i)));
+  }
+  keys.resize(key_str.size());
+  pin_values.clear();
+  pin_values.resize(key_str.size());
+  for (i = 0; i < key_str.size(); ++i) {
+    keys[i] = Slice(key_str[i].data(), key_str[i].size());
+  }
+  statuses.clear();
+  statuses.resize(keys.size());
+  ro.deadline = std::chrono::microseconds{env->NowMicros() + 10000};
+  fs->SetDelayTrigger(ro.deadline, ro.io_timeout, 1);
+  dbfull()->MultiGet(ro, handles_[0], keys.size(), keys.data(),
+                     pin_values.data(), statuses.data());
+  CheckStatus(statuses, 64);
+  Close();
+}
+
+INSTANTIATE_TEST_CASE_P(DeadlineIO, DBBasicTestMultiGetDeadline,
+                        ::testing::Bool());
+
+TEST_F(DBBasicTest, ManifestWriteFailure) {
+  Options options = GetDefaultOptions();
+  options.create_if_missing = true;
+  options.disable_auto_compactions = true;
+  options.env = env_;
+  DestroyAndReopen(options);
+  ASSERT_OK(Put("foo", "bar"));
+  ASSERT_OK(Flush());
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  SyncPoint::GetInstance()->SetCallBack(
+      "VersionSet::ProcessManifestWrites:AfterSyncManifest", [&](void* arg) {
+        ASSERT_NE(nullptr, arg);
+        auto* s = reinterpret_cast<Status*>(arg);
+        ASSERT_OK(*s);
+        // Manually overwrite return status
+        *s = Status::IOError();
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+  ASSERT_OK(Put("key", "value"));
+  ASSERT_NOK(Flush());
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  SyncPoint::GetInstance()->EnableProcessing();
+  Reopen(options);
+}
+
+TEST_F(DBBasicTest, DestroyDefaultCfHandle) {
+  Options options = GetDefaultOptions();
+  options.create_if_missing = true;
+  DestroyAndReopen(options);
+  CreateAndReopenWithCF({"pikachu"}, options);
+  for (const auto* h : handles_) {
+    ASSERT_NE(db_->DefaultColumnFamily(), h);
+  }
+
+  // We have two handles to the default column family. The two handles point to
+  // different ColumnFamilyHandle objects.
+  assert(db_->DefaultColumnFamily());
+  ASSERT_EQ(0U, db_->DefaultColumnFamily()->GetID());
+  assert(handles_[0]);
+  ASSERT_EQ(0U, handles_[0]->GetID());
+
+  // You can destroy handles_[...].
+  for (auto* h : handles_) {
+    ASSERT_OK(db_->DestroyColumnFamilyHandle(h));
+  }
+  handles_.clear();
+
+  // But you should not destroy db_->DefaultColumnFamily(), since it's going to
+  // be deleted in `DBImpl::CloseHelper()`. Before that, it may be used
+  // elsewhere internally too.
+  ColumnFamilyHandle* default_cf = db_->DefaultColumnFamily();
+  ASSERT_TRUE(db_->DestroyColumnFamilyHandle(default_cf).IsInvalidArgument());
+}
+
+TEST_F(DBBasicTest, FailOpenIfLoggerCreationFail) {
+  Options options = GetDefaultOptions();
+  options.create_if_missing = true;
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  SyncPoint::GetInstance()->SetCallBack(
+      "rocksdb::CreateLoggerFromOptions:AfterGetPath", [&](void* arg) {
+        auto* s = reinterpret_cast<Status*>(arg);
+        assert(s);
+        *s = Status::IOError("Injected");
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  Status s = TryReopen(options);
+  ASSERT_EQ(nullptr, options.info_log);
+  ASSERT_TRUE(s.IsIOError());
+
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+}
+
+#ifndef ROCKSDB_LITE
+TEST_F(DBBasicTest, VerifyFileChecksums) {
+  Options options = GetDefaultOptions();
+  options.create_if_missing = true;
+  options.env = env_;
+  DestroyAndReopen(options);
+  ASSERT_OK(Put("a", "value"));
+  ASSERT_OK(Flush());
+  ASSERT_TRUE(db_->VerifyFileChecksums(ReadOptions()).IsInvalidArgument());
+
+  options.file_checksum_gen_factory = GetFileChecksumGenCrc32cFactory();
+  Reopen(options);
+  ASSERT_OK(db_->VerifyFileChecksums(ReadOptions()));
+
+  // Write an L0 with checksum computed.
+  ASSERT_OK(Put("b", "value"));
+  ASSERT_OK(Flush());
+
+  ASSERT_OK(db_->VerifyFileChecksums(ReadOptions()));
+
+  // Does the right thing but with the wrong name -- using it should lead to an
+  // error.
+  class MisnamedFileChecksumGenerator : public FileChecksumGenCrc32c {
+   public:
+    MisnamedFileChecksumGenerator(const FileChecksumGenContext& context)
+        : FileChecksumGenCrc32c(context) {}
+
+    const char* Name() const override { return "sha1"; }
+  };
+
+  class MisnamedFileChecksumGenFactory : public FileChecksumGenCrc32cFactory {
+   public:
+    std::unique_ptr<FileChecksumGenerator> CreateFileChecksumGenerator(
+        const FileChecksumGenContext& context) override {
+      return std::unique_ptr<FileChecksumGenerator>(
+          new MisnamedFileChecksumGenerator(context));
+    }
+  };
+
+  options.file_checksum_gen_factory.reset(new MisnamedFileChecksumGenFactory());
+  Reopen(options);
+  ASSERT_TRUE(db_->VerifyFileChecksums(ReadOptions()).IsInvalidArgument());
+}
+
+// TODO: re-enable after we provide finer-grained control for WAL tracking to
+// meet the needs of different use cases, durability levels and recovery modes.
+TEST_F(DBBasicTest, DISABLED_ManualWalSync) {
+  Options options = CurrentOptions();
+  options.track_and_verify_wals_in_manifest = true;
+  options.wal_recovery_mode = WALRecoveryMode::kAbsoluteConsistency;
+  DestroyAndReopen(options);
+
+  ASSERT_OK(Put("x", "y"));
+  // This does not create a new WAL.
+  ASSERT_OK(db_->SyncWAL());
+  EXPECT_FALSE(dbfull()->GetVersionSet()->GetWalSet().GetWals().empty());
+
+  std::unique_ptr<LogFile> wal;
+  Status s = db_->GetCurrentWalFile(&wal);
+  ASSERT_OK(s);
+  Close();
+
+  EXPECT_OK(env_->DeleteFile(LogFileName(dbname_, wal->LogNumber())));
+
+  ASSERT_TRUE(TryReopen(options).IsCorruption());
+}
+#endif  // !ROCKSDB_LITE
+
+// A test class for intercepting random reads and injecting artificial
+// delays. Used for testing the deadline/timeout feature
+class DBBasicTestDeadline
+    : public DBBasicTest,
+      public testing::WithParamInterface<std::tuple<bool, bool>> {};
+
+TEST_P(DBBasicTestDeadline, PointLookupDeadline) {
+  std::shared_ptr<DeadlineFS> fs = std::make_shared<DeadlineFS>(env_, true);
+  std::unique_ptr<Env> env(new CompositeEnvWrapper(env_, fs));
+  bool set_deadline = std::get<0>(GetParam());
+  bool set_timeout = std::get<1>(GetParam());
+
+  for (int option_config = kDefault; option_config < kEnd; ++option_config) {
+    if (ShouldSkipOptions(option_config, kSkipPlainTable | kSkipMmapReads)) {
+      continue;
+    }
+    option_config_ = option_config;
+    Options options = CurrentOptions();
+    if (options.use_direct_reads) {
+      continue;
+    }
+    options.env = env.get();
+    options.disable_auto_compactions = true;
+    Cache* block_cache = nullptr;
+    // Fileter block reads currently don't cause the request to get
+    // aborted on a read timeout, so its possible those block reads
+    // may get issued even if the deadline is past
+    SyncPoint::GetInstance()->SetCallBack(
+        "BlockBasedTable::Get:BeforeFilterMatch",
+        [&](void* /*arg*/) { fs->IgnoreDeadline(true); });
+    SyncPoint::GetInstance()->SetCallBack(
+        "BlockBasedTable::Get:AfterFilterMatch",
+        [&](void* /*arg*/) { fs->IgnoreDeadline(false); });
+    // DB open will create table readers unless we reduce the table cache
+    // capacity.
+    // SanitizeOptions will set max_open_files to minimum of 20. Table cache
+    // is allocated with max_open_files - 10 as capacity. So override
+    // max_open_files to 11 so table cache capacity will become 1. This will
+    // prevent file open during DB open and force the file to be opened
+    // during MultiGet
+    SyncPoint::GetInstance()->SetCallBack(
+        "SanitizeOptions::AfterChangeMaxOpenFiles", [&](void* arg) {
+          int* max_open_files = (int*)arg;
+          *max_open_files = 11;
+        });
+    SyncPoint::GetInstance()->EnableProcessing();
+
+    SetTimeElapseOnlySleepOnReopen(&options);
+    Reopen(options);
+
+    if (options.table_factory) {
+      block_cache = options.table_factory->GetOptions<Cache>(
+          TableFactory::kBlockCacheOpts());
+    }
+
+    Random rnd(301);
+    for (int i = 0; i < 400; ++i) {
+      std::string key = "k" + std::to_string(i);
+      ASSERT_OK(Put(key, rnd.RandomString(100)));
+    }
+    ASSERT_OK(Flush());
+
+    bool timedout = true;
+    // A timeout will be forced when the IO counter reaches this value
+    int io_deadline_trigger = 0;
+    // Keep incrementing io_deadline_trigger and call Get() until there is an
+    // iteration that doesn't cause a timeout. This ensures that we cover
+    // all file reads in the point lookup path that can potentially timeout
+    // and cause the Get() to fail.
+    while (timedout) {
+      ReadOptions ro;
+      if (set_deadline) {
+        ro.deadline = std::chrono::microseconds{env->NowMicros() + 10000};
+      }
+      if (set_timeout) {
+        ro.io_timeout = std::chrono::microseconds{5000};
+      }
+      fs->SetDelayTrigger(ro.deadline, ro.io_timeout, io_deadline_trigger);
+
+      block_cache->SetCapacity(0);
+      block_cache->SetCapacity(1048576);
+
+      std::string value;
+      Status s = dbfull()->Get(ro, "k50", &value);
+      if (fs->TimedOut()) {
+        ASSERT_EQ(s, Status::TimedOut());
+      } else {
+        timedout = false;
+        ASSERT_OK(s);
+      }
+      io_deadline_trigger++;
+    }
+    // Reset the delay sequence in order to avoid false alarms during Reopen
+    fs->SetDelayTrigger(std::chrono::microseconds::zero(),
+                        std::chrono::microseconds::zero(), 0);
+  }
+  Close();
+}
+
+TEST_P(DBBasicTestDeadline, IteratorDeadline) {
+  std::shared_ptr<DeadlineFS> fs = std::make_shared<DeadlineFS>(env_, true);
+  std::unique_ptr<Env> env(new CompositeEnvWrapper(env_, fs));
+  bool set_deadline = std::get<0>(GetParam());
+  bool set_timeout = std::get<1>(GetParam());
+
+  for (int option_config = kDefault; option_config < kEnd; ++option_config) {
+    if (ShouldSkipOptions(option_config, kSkipPlainTable | kSkipMmapReads)) {
+      continue;
+    }
+    Options options = CurrentOptions();
+    if (options.use_direct_reads) {
+      continue;
+    }
+    options.env = env.get();
+    options.disable_auto_compactions = true;
+    Cache* block_cache = nullptr;
+    // DB open will create table readers unless we reduce the table cache
+    // capacity.
+    // SanitizeOptions will set max_open_files to minimum of 20. Table cache
+    // is allocated with max_open_files - 10 as capacity. So override
+    // max_open_files to 11 so table cache capacity will become 1. This will
+    // prevent file open during DB open and force the file to be opened
+    // during MultiGet
+    SyncPoint::GetInstance()->SetCallBack(
+        "SanitizeOptions::AfterChangeMaxOpenFiles", [&](void* arg) {
+          int* max_open_files = (int*)arg;
+          *max_open_files = 11;
+        });
+    SyncPoint::GetInstance()->EnableProcessing();
+
+    SetTimeElapseOnlySleepOnReopen(&options);
+    Reopen(options);
+
+    if (options.table_factory) {
+      block_cache = options.table_factory->GetOptions<Cache>(
+          TableFactory::kBlockCacheOpts());
+    }
+
+    Random rnd(301);
+    for (int i = 0; i < 400; ++i) {
+      std::string key = "k" + std::to_string(i);
+      ASSERT_OK(Put(key, rnd.RandomString(100)));
+    }
+    ASSERT_OK(Flush());
+
+    bool timedout = true;
+    // A timeout will be forced when the IO counter reaches this value
+    int io_deadline_trigger = 0;
+    // Keep incrementing io_deadline_trigger and call Get() until there is an
+    // iteration that doesn't cause a timeout. This ensures that we cover
+    // all file reads in the point lookup path that can potentially timeout
+    while (timedout) {
+      ReadOptions ro;
+      if (set_deadline) {
+        ro.deadline = std::chrono::microseconds{env->NowMicros() + 10000};
+      }
+      if (set_timeout) {
+        ro.io_timeout = std::chrono::microseconds{5000};
+      }
+      fs->SetDelayTrigger(ro.deadline, ro.io_timeout, io_deadline_trigger);
+
+      block_cache->SetCapacity(0);
+      block_cache->SetCapacity(1048576);
+
+      Iterator* iter = dbfull()->NewIterator(ro);
+      int count = 0;
+      iter->Seek("k50");
+      while (iter->Valid() && count++ < 100) {
+        iter->Next();
+      }
+      if (fs->TimedOut()) {
+        ASSERT_FALSE(iter->Valid());
+        ASSERT_EQ(iter->status(), Status::TimedOut());
+      } else {
+        timedout = false;
+        ASSERT_OK(iter->status());
+      }
+      delete iter;
+      io_deadline_trigger++;
+    }
+    // Reset the delay sequence in order to avoid false alarms during Reopen
+    fs->SetDelayTrigger(std::chrono::microseconds::zero(),
+                        std::chrono::microseconds::zero(), 0);
+  }
+  Close();
+}
+
+// Param 0: If true, set read_options.deadline
+// Param 1: If true, set read_options.io_timeout
+INSTANTIATE_TEST_CASE_P(DBBasicTestDeadline, DBBasicTestDeadline,
+                        ::testing::Values(std::make_tuple(true, false),
+                                          std::make_tuple(false, true),
+                                          std::make_tuple(true, true)));
+}  // namespace ROCKSDB_NAMESPACE
+
+int main(int argc, char** argv) {
+  ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
+  ::testing::InitGoogleTest(&argc, argv);
+  RegisterCustomObjects(argc, argv);
+  return RUN_ALL_TESTS();
+}