1 files changed, 225 insertions, 0 deletions
diff --git a/src/rocksdb/db_stress_tool/db_stress_common.cc b/src/rocksdb/db_stress_tool/db_stress_common.cc
new file mode 100644
index 000000000..953cfe505
--- /dev/null
+++ b/src/rocksdb/db_stress_tool/db_stress_common.cc
@@ -0,0 +1,225 @@
+//  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.
+//
+
+#ifdef GFLAGS
+#include "db_stress_tool/db_stress_common.h"
+#include <cmath>
+
+ROCKSDB_NAMESPACE::DbStressEnvWrapper* db_stress_env = nullptr;
+enum ROCKSDB_NAMESPACE::CompressionType compression_type_e =
+    ROCKSDB_NAMESPACE::kSnappyCompression;
+enum ROCKSDB_NAMESPACE::CompressionType bottommost_compression_type_e =
+    ROCKSDB_NAMESPACE::kSnappyCompression;
+enum ROCKSDB_NAMESPACE::ChecksumType checksum_type_e =
+    ROCKSDB_NAMESPACE::kCRC32c;
+enum RepFactory FLAGS_rep_factory = kSkipList;
+std::vector<double> sum_probs(100001);
+int64_t zipf_sum_size = 100000;
+
+namespace ROCKSDB_NAMESPACE {
+
+// Zipfian distribution is generated based on a pre-calculated array.
+// It should be used before start the stress test.
+// First, the probability distribution function (PDF) of this Zipfian follows
+// power low. P(x) = 1/(x^alpha).
+// So we calculate the PDF when x is from 0 to zipf_sum_size in first for loop
+// and add the PDF value togetger as c. So we get the total probability in c.
+// Next, we calculate inverse CDF of Zipfian and store the value of each in
+// an array (sum_probs). The rank is from 0 to zipf_sum_size. For example, for
+// integer k, its Zipfian CDF value is sum_probs[k].
+// Third, when we need to get an integer whose probability follows Zipfian
+// distribution, we use a rand_seed [0,1] which follows uniform distribution
+// as a seed and search it in the sum_probs via binary search. When we find
+// the closest sum_probs[i] of rand_seed, i is the integer that in
+// [0, zipf_sum_size] following Zipfian distribution with parameter alpha.
+// Finally, we can scale i to [0, max_key] scale.
+// In order to avoid that hot keys are close to each other and skew towards 0,
+// we use Rando64 to shuffle it.
+void InitializeHotKeyGenerator(double alpha) {
+  double c = 0;
+  for (int64_t i = 1; i <= zipf_sum_size; i++) {
+    c = c + (1.0 / std::pow(static_cast<double>(i), alpha));
+  }
+  c = 1.0 / c;
+
+  sum_probs[0] = 0;
+  for (int64_t i = 1; i <= zipf_sum_size; i++) {
+    sum_probs[i] =
+        sum_probs[i - 1] + c / std::pow(static_cast<double>(i), alpha);
+  }
+}
+
+// Generate one key that follows the Zipfian distribution. The skewness
+// is decided by the parameter alpha. Input is the rand_seed [0,1] and
+// the max of the key to be generated. If we directly return tmp_zipf_seed,
+// the closer to 0, the higher probability will be. To randomly distribute
+// the hot keys in [0, max_key], we use Random64 to shuffle it.
+int64_t GetOneHotKeyID(double rand_seed, int64_t max_key) {
+  int64_t low = 1, mid, high = zipf_sum_size, zipf = 0;
+  while (low <= high) {
+    mid = (low + high) / 2;
+    if (sum_probs[mid] >= rand_seed && sum_probs[mid - 1] < rand_seed) {
+      zipf = mid;
+      break;
+    } else if (sum_probs[mid] >= rand_seed) {
+      high = mid - 1;
+    } else {
+      low = mid + 1;
+    }
+  }
+  int64_t tmp_zipf_seed = zipf * max_key / zipf_sum_size;
+  Random64 rand_local(tmp_zipf_seed);
+  return rand_local.Next() % max_key;
+}
+
+void PoolSizeChangeThread(void* v) {
+  assert(FLAGS_compaction_thread_pool_adjust_interval > 0);
+  ThreadState* thread = reinterpret_cast<ThreadState*>(v);
+  SharedState* shared = thread->shared;
+
+  while (true) {
+    {
+      MutexLock l(shared->GetMutex());
+      if (shared->ShouldStopBgThread()) {
+        shared->IncBgThreadsFinished();
+        if (shared->BgThreadsFinished()) {
+          shared->GetCondVar()->SignalAll();
+        }
+        return;
+      }
+    }
+
+    auto thread_pool_size_base = FLAGS_max_background_compactions;
+    auto thread_pool_size_var = FLAGS_compaction_thread_pool_variations;
+    int new_thread_pool_size =
+        thread_pool_size_base - thread_pool_size_var +
+        thread->rand.Next() % (thread_pool_size_var * 2 + 1);
+    if (new_thread_pool_size < 1) {
+      new_thread_pool_size = 1;
+    }
+    db_stress_env->SetBackgroundThreads(new_thread_pool_size,
+                                        ROCKSDB_NAMESPACE::Env::Priority::LOW);
+    // Sleep up to 3 seconds
+    db_stress_env->SleepForMicroseconds(
+        thread->rand.Next() % FLAGS_compaction_thread_pool_adjust_interval *
+            1000 +
+        1);
+  }
+}
+
+void DbVerificationThread(void* v) {
+  assert(FLAGS_continuous_verification_interval > 0);
+  auto* thread = reinterpret_cast<ThreadState*>(v);
+  SharedState* shared = thread->shared;
+  StressTest* stress_test = shared->GetStressTest();
+  assert(stress_test != nullptr);
+  while (true) {
+    {
+      MutexLock l(shared->GetMutex());
+      if (shared->ShouldStopBgThread()) {
+        shared->IncBgThreadsFinished();
+        if (shared->BgThreadsFinished()) {
+          shared->GetCondVar()->SignalAll();
+        }
+        return;
+      }
+    }
+    if (!shared->HasVerificationFailedYet()) {
+      stress_test->ContinuouslyVerifyDb(thread);
+    }
+    db_stress_env->SleepForMicroseconds(
+        thread->rand.Next() % FLAGS_continuous_verification_interval * 1000 +
+        1);
+  }
+}
+
+void PrintKeyValue(int cf, uint64_t key, const char* value, size_t sz) {
+  if (!FLAGS_verbose) {
+    return;
+  }
+  std::string tmp;
+  tmp.reserve(sz * 2 + 16);
+  char buf[4];
+  for (size_t i = 0; i < sz; i++) {
+    snprintf(buf, 4, "%X", value[i]);
+    tmp.append(buf);
+  }
+  fprintf(stdout, "[CF %d] %" PRIi64 " == > (%" ROCKSDB_PRIszt ") %s\n", cf,
+          key, sz, tmp.c_str());
+}
+
+// Note that if hot_key_alpha != 0, it generates the key based on Zipfian
+// distribution. Keys are randomly scattered to [0, FLAGS_max_key]. It does
+// not ensure the order of the keys being generated and the keys does not have
+// the active range which is related to FLAGS_active_width.
+int64_t GenerateOneKey(ThreadState* thread, uint64_t iteration) {
+  const double completed_ratio =
+      static_cast<double>(iteration) / FLAGS_ops_per_thread;
+  const int64_t base_key = static_cast<int64_t>(
+      completed_ratio * (FLAGS_max_key - FLAGS_active_width));
+  int64_t rand_seed = base_key + thread->rand.Next() % FLAGS_active_width;
+  int64_t cur_key = rand_seed;
+  if (FLAGS_hot_key_alpha != 0) {
+    // If set the Zipfian distribution Alpha to non 0, use Zipfian
+    double float_rand =
+        (static_cast<double>(thread->rand.Next() % FLAGS_max_key)) /
+        FLAGS_max_key;
+    cur_key = GetOneHotKeyID(float_rand, FLAGS_max_key);
+  }
+  return cur_key;
+}
+
+// Note that if hot_key_alpha != 0, it generates the key based on Zipfian
+// distribution. Keys being generated are in random order.
+// If user want to generate keys based on uniform distribution, user needs to
+// set hot_key_alpha == 0. It will generate the random keys in increasing
+// order in the key array (ensure key[i] >= key[i+1]) and constrained in a
+// range related to FLAGS_active_width.
+std::vector<int64_t> GenerateNKeys(ThreadState* thread, int num_keys,
+                                   uint64_t iteration) {
+  const double completed_ratio =
+      static_cast<double>(iteration) / FLAGS_ops_per_thread;
+  const int64_t base_key = static_cast<int64_t>(
+      completed_ratio * (FLAGS_max_key - FLAGS_active_width));
+  std::vector<int64_t> keys;
+  keys.reserve(num_keys);
+  int64_t next_key = base_key + thread->rand.Next() % FLAGS_active_width;
+  keys.push_back(next_key);
+  for (int i = 1; i < num_keys; ++i) {
+    // Generate the key follows zipfian distribution
+    if (FLAGS_hot_key_alpha != 0) {
+      double float_rand =
+          (static_cast<double>(thread->rand.Next() % FLAGS_max_key)) /
+          FLAGS_max_key;
+      next_key = GetOneHotKeyID(float_rand, FLAGS_max_key);
+    } else {
+      // This may result in some duplicate keys
+      next_key = next_key + thread->rand.Next() %
+                                (FLAGS_active_width - (next_key - base_key));
+    }
+    keys.push_back(next_key);
+  }
+  return keys;
+}
+
+size_t GenerateValue(uint32_t rand, char* v, size_t max_sz) {
+  size_t value_sz =
+      ((rand % kRandomValueMaxFactor) + 1) * FLAGS_value_size_mult;
+  assert(value_sz <= max_sz && value_sz >= sizeof(uint32_t));
+  (void)max_sz;
+  *((uint32_t*)v) = rand;
+  for (size_t i = sizeof(uint32_t); i < value_sz; i++) {
+    v[i] = (char)(rand ^ i);
+  }
+  v[value_sz] = '\0';
+  return value_sz;  // the size of the value set.
+}
+}  // namespace ROCKSDB_NAMESPACE
+#endif  // GFLAGS