Adding upstream version 5:7.0.15.upstream/5%7.0.15upstream

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

37 files changed, 2907 insertions, 0 deletions

diff --git a/utils/build-static-symbols.tcl b/utils/build-static-symbols.tcl
new file mode 100644
index 0000000..e634cbe
--- /dev/null
+++ b/utils/build-static-symbols.tcl
@@ -0,0 +1,22 @@
+# Build a symbol table for static symbols of redis.c
+# Useful to get stack traces on segfault without a debugger. See redis.c
+# for more information.
+#
+# Copyright(C) 2009 Salvatore Sanfilippo, under the BSD license.
+
+set fd [open redis.c]
+set symlist {}
+while {[gets $fd line] != -1} {
+    if {[regexp {^static +[A-z0-9]+[ *]+([A-z0-9]*)\(} $line - sym]} {
+        lappend symlist $sym
+    }
+}
+set symlist [lsort -unique $symlist]
+puts "static struct redisFunctionSym symsTable\[\] = {"
+foreach sym $symlist {
+    puts "{\"$sym\",(unsigned long)$sym},"
+}
+puts "{NULL,0}"
+puts "};"
+
+close $fd
diff --git a/utils/cluster_fail_time.tcl b/utils/cluster_fail_time.tcl
new file mode 100644
index 0000000..8739949
--- /dev/null
+++ b/utils/cluster_fail_time.tcl
@@ -0,0 +1,50 @@
+# This simple script is used in order to estimate the average PFAIL->FAIL
+# state switch after a failure.
+
+set ::sleep_time 10     ; # How much to sleep to trigger PFAIL.
+set ::fail_port 30016   ; # Node to put in sleep.
+set ::other_port 30001  ; # Node to use to monitor the flag switch.
+
+proc avg vector {
+    set sum 0.0
+    foreach x $vector {
+        set sum [expr {$sum+$x}]
+    }
+    expr {$sum/[llength $vector]}
+}
+
+set samples {}
+while 1 {
+    exec redis-cli -p $::fail_port debug sleep $::sleep_time > /dev/null &
+
+    # Wait for fail? to appear.
+    while 1 {
+        set output [exec redis-cli -p $::other_port cluster nodes]
+        if {[string match {*fail\?*} $output]} break
+        after 100
+    }
+
+    puts "FAIL?"
+    set start [clock milliseconds]
+
+    # Wait for fail? to disappear.
+    while 1 {
+        set output [exec redis-cli -p $::other_port cluster nodes]
+        if {![string match {*fail\?*} $output]} break
+        after 100
+    }
+
+    puts "FAIL"
+    set now [clock milliseconds]
+    set elapsed [expr {$now-$start}]
+    puts $elapsed
+    lappend samples $elapsed
+
+    puts "AVG([llength $samples]): [avg $samples]"
+
+    # Wait for the instance to be available again.
+    exec redis-cli -p $::fail_port ping
+
+    # Wait for the fail flag to be cleared.
+    after 2000
+}
diff --git a/utils/corrupt_rdb.c b/utils/corrupt_rdb.c
new file mode 100644
index 0000000..df9c93e
--- /dev/null
+++ b/utils/corrupt_rdb.c
@@ -0,0 +1,45 @@
+/* Trivia program to corrupt an RDB file in order to check the RDB check
+ * program behavior and effectiveness.
+ *
+ * Copyright (C) 2016 Salvatore Sanfilippo.
+ * This software is released in the 3-clause BSD license. */
+
+#include <stdio.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <time.h>
+
+int main(int argc, char **argv) {
+    struct stat stat;
+    int fd, cycles;
+
+    if (argc != 3) {
+        fprintf(stderr,"Usage: <filename> <cycles>\n");
+        exit(1);
+    }
+
+    srand(time(NULL));
+    char *filename = argv[1];
+    cycles = atoi(argv[2]);
+    fd = open(filename,O_RDWR);
+    if (fd == -1) {
+        perror("open");
+        exit(1);
+    }
+    fstat(fd,&stat);
+
+    while(cycles--) {
+        unsigned char buf[32];
+        unsigned long offset = rand()%stat.st_size;
+        int writelen = 1+rand()%31;
+        int j;
+
+        for (j = 0; j < writelen; j++) buf[j] = (char)rand();
+        lseek(fd,offset,SEEK_SET);
+        printf("Writing %d bytes at offset %lu\n", writelen, offset);
+        write(fd,buf,writelen);
+    }
+    return 0;
+}
diff --git a/utils/create-cluster/.gitignore b/utils/create-cluster/.gitignore
new file mode 100644
index 0000000..a34b639
--- /dev/null
+++ b/utils/create-cluster/.gitignore
@@ -0,0 +1,6 @@
+config.sh
+*.rdb
+*.aof
+*.conf
+*.log
+appendonlydir-*
diff --git a/utils/create-cluster/README b/utils/create-cluster/README
new file mode 100644
index 0000000..bcd7459
--- /dev/null
+++ b/utils/create-cluster/README
@@ -0,0 +1,27 @@
+create-cluster is a small script used to easily start a big number of Redis
+instances configured to run in cluster mode. Its main goal is to allow manual
+testing in a condition which is not easy to replicate with the Redis cluster
+unit tests, for example when a lot of instances are needed in order to trigger
+a given bug.
+
+The tool can also be used just to easily create a number of instances in a
+Redis Cluster in order to experiment a bit with the system.
+
+USAGE
+---
+
+To create a cluster, follow these steps:
+
+1. Edit create-cluster and change the start / end port, depending on the
+number of instances you want to create.
+2. Use "./create-cluster start" in order to run the instances.
+3. Use "./create-cluster create" in order to execute redis-cli --cluster create, so that
+an actual Redis cluster will be created. (If you're accessing your setup via a local container, ensure that the CLUSTER_HOST value is changed to your local IP)
+4. Now you are ready to play with the cluster. AOF files and logs for each instances are created in the current directory.
+
+In order to stop a cluster:
+
+1. Use "./create-cluster stop" to stop all the instances. After you stopped the instances you can use "./create-cluster start" to restart them if you change your mind.
+2. Use "./create-cluster clean" to remove all the AOF / log files to restart with a clean environment.
+
+Use the command "./create-cluster help" to get the full list of features.
diff --git a/utils/create-cluster/create-cluster b/utils/create-cluster/create-cluster
new file mode 100755
index 0000000..d97ee2b
--- /dev/null
+++ b/utils/create-cluster/create-cluster
@@ -0,0 +1,125 @@
+#!/bin/bash
+
+SCRIPT_DIR="$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
+
+# Settings
+BIN_PATH="$SCRIPT_DIR/../../src/"
+CLUSTER_HOST=127.0.0.1
+PORT=30000
+TIMEOUT=2000
+NODES=6
+REPLICAS=1
+PROTECTED_MODE=yes
+ADDITIONAL_OPTIONS=""
+
+# You may want to put the above config parameters into config.sh in order to
+# override the defaults without modifying this script.
+
+if [ -a config.sh ]
+then
+    source "config.sh"
+fi
+
+# Computed vars
+ENDPORT=$((PORT+NODES))
+
+if [ "$1" == "start" ]
+then
+    while [ $((PORT < ENDPORT)) != "0" ]; do
+        PORT=$((PORT+1))
+        echo "Starting $PORT"
+        $BIN_PATH/redis-server --port $PORT --protected-mode $PROTECTED_MODE --cluster-enabled yes --cluster-config-file nodes-${PORT}.conf --cluster-node-timeout $TIMEOUT --appendonly yes --appendfilename appendonly-${PORT}.aof --appenddirname appendonlydir-${PORT} --dbfilename dump-${PORT}.rdb --logfile ${PORT}.log --daemonize yes ${ADDITIONAL_OPTIONS}
+    done
+    exit 0
+fi
+
+if [ "$1" == "create" ]
+then
+    HOSTS=""
+    while [ $((PORT < ENDPORT)) != "0" ]; do
+        PORT=$((PORT+1))
+        HOSTS="$HOSTS $CLUSTER_HOST:$PORT"
+    done
+    OPT_ARG=""
+    if [ "$2" == "-f" ]; then
+        OPT_ARG="--cluster-yes"
+    fi
+    $BIN_PATH/redis-cli --cluster create $HOSTS --cluster-replicas $REPLICAS $OPT_ARG
+    exit 0
+fi
+
+if [ "$1" == "stop" ]
+then
+    while [ $((PORT < ENDPORT)) != "0" ]; do
+        PORT=$((PORT+1))
+        echo "Stopping $PORT"
+        $BIN_PATH/redis-cli -p $PORT shutdown nosave
+    done
+    exit 0
+fi
+
+if [ "$1" == "watch" ]
+then
+    PORT=$((PORT+1))
+    while [ 1 ]; do
+        clear
+        date
+        $BIN_PATH/redis-cli -p $PORT cluster nodes | head -30
+        sleep 1
+    done
+    exit 0
+fi
+
+if [ "$1" == "tail" ]
+then
+    INSTANCE=$2
+    PORT=$((PORT+INSTANCE))
+    tail -f ${PORT}.log
+    exit 0
+fi
+
+if [ "$1" == "tailall" ]
+then
+    tail -f *.log
+    exit 0
+fi
+
+if [ "$1" == "call" ]
+then
+    while [ $((PORT < ENDPORT)) != "0" ]; do
+        PORT=$((PORT+1))
+        $BIN_PATH/redis-cli -p $PORT $2 $3 $4 $5 $6 $7 $8 $9
+    done
+    exit 0
+fi
+
+if [ "$1" == "clean" ]
+then
+    echo "Cleaning *.log"
+    rm -rf *.log
+    echo "Cleaning appendonlydir-*"
+    rm -rf appendonlydir-*
+    echo "Cleaning dump-*.rdb"
+    rm -rf dump-*.rdb
+    echo "Cleaning nodes-*.conf"
+    rm -rf nodes-*.conf
+    exit 0
+fi
+
+if [ "$1" == "clean-logs" ]
+then
+    echo "Cleaning *.log"
+    rm -rf *.log
+    exit 0
+fi
+
+echo "Usage: $0 [start|create|stop|watch|tail|tailall|clean|clean-logs|call]"
+echo "start       -- Launch Redis Cluster instances."
+echo "create [-f] -- Create a cluster using redis-cli --cluster create."
+echo "stop        -- Stop Redis Cluster instances."
+echo "watch       -- Show CLUSTER NODES output (first 30 lines) of first node."
+echo "tail <id>   -- Run tail -f of instance at base port + ID."
+echo "tailall     -- Run tail -f for all the log files at once."
+echo "clean       -- Remove all instances data, logs, configs."
+echo "clean-logs  -- Remove just instances logs."
+echo "call <cmd>  -- Call a command (up to 7 arguments) on all nodes."
diff --git a/utils/gen-test-certs.sh b/utils/gen-test-certs.sh
new file mode 100755
index 0000000..6bc9d86
--- /dev/null
+++ b/utils/gen-test-certs.sh
@@ -0,0 +1,58 @@
+#!/bin/bash
+
+# Generate some test certificates which are used by the regression test suite:
+#
+#   tests/tls/ca.{crt,key}          Self signed CA certificate.
+#   tests/tls/redis.{crt,key}       A certificate with no key usage/policy restrictions.
+#   tests/tls/client.{crt,key}      A certificate restricted for SSL client usage.
+#   tests/tls/server.{crt,key}      A certificate restricted for SSL server usage.
+#   tests/tls/redis.dh              DH Params file.
+
+generate_cert() {
+    local name=$1
+    local cn="$2"
+    local opts="$3"
+
+    local keyfile=tests/tls/${name}.key
+    local certfile=tests/tls/${name}.crt
+
+    [ -f $keyfile ] || openssl genrsa -out $keyfile 2048
+    openssl req \
+        -new -sha256 \
+        -subj "/O=Redis Test/CN=$cn" \
+        -key $keyfile | \
+        openssl x509 \
+            -req -sha256 \
+            -CA tests/tls/ca.crt \
+            -CAkey tests/tls/ca.key \
+            -CAserial tests/tls/ca.txt \
+            -CAcreateserial \
+            -days 365 \
+            $opts \
+            -out $certfile
+}
+
+mkdir -p tests/tls
+[ -f tests/tls/ca.key ] || openssl genrsa -out tests/tls/ca.key 4096
+openssl req \
+    -x509 -new -nodes -sha256 \
+    -key tests/tls/ca.key \
+    -days 3650 \
+    -subj '/O=Redis Test/CN=Certificate Authority' \
+    -out tests/tls/ca.crt
+
+cat > tests/tls/openssl.cnf <<_END_
+[ server_cert ]
+keyUsage = digitalSignature, keyEncipherment
+nsCertType = server
+
+[ client_cert ]
+keyUsage = digitalSignature, keyEncipherment
+nsCertType = client
+_END_
+
+generate_cert server "Server-only" "-extfile tests/tls/openssl.cnf -extensions server_cert"
+generate_cert client "Client-only" "-extfile tests/tls/openssl.cnf -extensions client_cert"
+generate_cert redis "Generic-cert"
+
+[ -f tests/tls/redis.dh ] || openssl dhparam -out tests/tls/redis.dh 2048
diff --git a/utils/generate-command-code.py b/utils/generate-command-code.py
new file mode 100755
index 0000000..605bde4
--- /dev/null
+++ b/utils/generate-command-code.py
@@ -0,0 +1,489 @@
+#!/usr/bin/env python3
+import glob
+import json
+import os
+
+ARG_TYPES = {
+    "string": "ARG_TYPE_STRING",
+    "integer": "ARG_TYPE_INTEGER",
+    "double": "ARG_TYPE_DOUBLE",
+    "key": "ARG_TYPE_KEY",
+    "pattern": "ARG_TYPE_PATTERN",
+    "unix-time": "ARG_TYPE_UNIX_TIME",
+    "pure-token": "ARG_TYPE_PURE_TOKEN",
+    "oneof": "ARG_TYPE_ONEOF",
+    "block": "ARG_TYPE_BLOCK",
+}
+
+GROUPS = {
+    "generic": "COMMAND_GROUP_GENERIC",
+    "string": "COMMAND_GROUP_STRING",
+    "list": "COMMAND_GROUP_LIST",
+    "set": "COMMAND_GROUP_SET",
+    "sorted_set": "COMMAND_GROUP_SORTED_SET",
+    "hash": "COMMAND_GROUP_HASH",
+    "pubsub": "COMMAND_GROUP_PUBSUB",
+    "transactions": "COMMAND_GROUP_TRANSACTIONS",
+    "connection": "COMMAND_GROUP_CONNECTION",
+    "server": "COMMAND_GROUP_SERVER",
+    "scripting": "COMMAND_GROUP_SCRIPTING",
+    "hyperloglog": "COMMAND_GROUP_HYPERLOGLOG",
+    "cluster": "COMMAND_GROUP_CLUSTER",
+    "sentinel": "COMMAND_GROUP_SENTINEL",
+    "geo": "COMMAND_GROUP_GEO",
+    "stream": "COMMAND_GROUP_STREAM",
+    "bitmap": "COMMAND_GROUP_BITMAP",
+}
+
+RESP2_TYPES = {
+    "simple-string": "RESP2_SIMPLE_STRING",
+    "error": "RESP2_ERROR",
+    "integer": "RESP2_INTEGER",
+    "bulk-string": "RESP2_BULK_STRING",
+    "null-bulk-string": "RESP2_NULL_BULK_STRING",
+    "array": "RESP2_ARRAY",
+    "null-array": "RESP2_NULL_ARRAY",
+}
+
+RESP3_TYPES = {
+    "simple-string": "RESP3_SIMPLE_STRING",
+    "error": "RESP3_ERROR",
+    "integer": "RESP3_INTEGER",
+    "double": "RESP3_DOUBLE",
+    "bulk-string": "RESP3_BULK_STRING",
+    "array": "RESP3_ARRAY",
+    "map": "RESP3_MAP",
+    "set": "RESP3_SET",
+    "bool": "RESP3_BOOL",
+    "null": "RESP3_NULL",
+}
+
+
+def get_optional_desc_string(desc, field, force_uppercase=False):
+    v = desc.get(field, None)
+    if v and force_uppercase:
+        v = v.upper()
+    ret = "\"%s\"" % v if v else "NULL"
+    return ret.replace("\n", "\\n")
+
+
+def check_command_args_key_specs(args, command_key_specs_index_set, command_arg_key_specs_index_set):
+    if not args:
+        return True
+
+    for arg in args:
+        if arg.key_spec_index is not None:
+            assert isinstance(arg.key_spec_index, int)
+
+            if arg.key_spec_index not in command_key_specs_index_set:
+                print("command: %s arg: %s key_spec_index error" % (command.fullname(), arg.name))
+                return False
+
+            command_arg_key_specs_index_set.add(arg.key_spec_index)
+
+        if not check_command_args_key_specs(arg.subargs, command_key_specs_index_set, command_arg_key_specs_index_set):
+            return False
+
+    return True
+
+def check_command_key_specs(command):
+    if not command.key_specs:
+        return True
+
+    assert isinstance(command.key_specs, list)
+
+    for cmd_key_spec in command.key_specs:
+        if "flags" not in cmd_key_spec:
+            print("command: %s key_specs missing flags" % command.fullname())
+            return False
+
+        if "NOT_KEY" in cmd_key_spec["flags"]:
+            # Like SUNSUBSCRIBE / SPUBLISH / SSUBSCRIBE
+            return True
+
+    command_key_specs_index_set = set(range(len(command.key_specs)))
+    command_arg_key_specs_index_set = set()
+
+    # Collect key_spec used for each arg, including arg.subarg
+    if not check_command_args_key_specs(command.args, command_key_specs_index_set, command_arg_key_specs_index_set):
+        return False
+
+    # Check if we have key_specs not used
+    if command_key_specs_index_set != command_arg_key_specs_index_set:
+        print("command: %s may have unused key_spec" % command.fullname())
+        return False
+
+    return True
+
+
+# Globals
+subcommands = {}  # container_name -> dict(subcommand_name -> Subcommand) - Only subcommands
+commands = {}  # command_name -> Command - Only commands
+
+
+class KeySpec(object):
+    def __init__(self, spec):
+        self.spec = spec
+
+    def struct_code(self):
+        def _flags_code():
+            s = ""
+            for flag in self.spec.get("flags", []):
+                s += "CMD_KEY_%s|" % flag
+            return s[:-1] if s else 0
+
+        def _begin_search_code():
+            if self.spec["begin_search"].get("index"):
+                return "KSPEC_BS_INDEX,.bs.index={%d}" % (
+                    self.spec["begin_search"]["index"]["pos"]
+                )
+            elif self.spec["begin_search"].get("keyword"):
+                return "KSPEC_BS_KEYWORD,.bs.keyword={\"%s\",%d}" % (
+                    self.spec["begin_search"]["keyword"]["keyword"],
+                    self.spec["begin_search"]["keyword"]["startfrom"],
+                )
+            elif "unknown" in self.spec["begin_search"]:
+                return "KSPEC_BS_UNKNOWN,{{0}}"
+            else:
+                print("Invalid begin_search! value=%s" % self.spec["begin_search"])
+                exit(1)
+
+        def _find_keys_code():
+            if self.spec["find_keys"].get("range"):
+                return "KSPEC_FK_RANGE,.fk.range={%d,%d,%d}" % (
+                    self.spec["find_keys"]["range"]["lastkey"],
+                    self.spec["find_keys"]["range"]["step"],
+                    self.spec["find_keys"]["range"]["limit"]
+                )
+            elif self.spec["find_keys"].get("keynum"):
+                return "KSPEC_FK_KEYNUM,.fk.keynum={%d,%d,%d}" % (
+                    self.spec["find_keys"]["keynum"]["keynumidx"],
+                    self.spec["find_keys"]["keynum"]["firstkey"],
+                    self.spec["find_keys"]["keynum"]["step"]
+                )
+            elif "unknown" in self.spec["find_keys"]:
+                return "KSPEC_FK_UNKNOWN,{{0}}"
+            else:
+                print("Invalid find_keys! value=%s" % self.spec["find_keys"])
+                exit(1)
+
+        return "%s,%s,%s,%s" % (
+            get_optional_desc_string(self.spec, "notes"),
+            _flags_code(),
+            _begin_search_code(),
+            _find_keys_code()
+        )
+
+
+class Argument(object):
+    def __init__(self, parent_name, desc):
+        self.desc = desc
+        self.name = self.desc["name"].lower()
+        self.type = self.desc["type"]
+        self.key_spec_index = self.desc.get("key_spec_index", None)
+        self.parent_name = parent_name
+        self.subargs = []
+        self.subargs_name = None
+        if self.type in ["oneof", "block"]:
+            for subdesc in self.desc["arguments"]:
+                self.subargs.append(Argument(self.fullname(), subdesc))
+
+    def fullname(self):
+        return ("%s %s" % (self.parent_name, self.name)).replace("-", "_")
+
+    def struct_name(self):
+        return "%s_Arg" % (self.fullname().replace(" ", "_"))
+
+    def subarg_table_name(self):
+        assert self.subargs
+        return "%s_Subargs" % (self.fullname().replace(" ", "_"))
+
+    def struct_code(self):
+        """
+        Output example:
+        "expiration",ARG_TYPE_ONEOF,NULL,NULL,NULL,CMD_ARG_OPTIONAL,.value.subargs=SET_expiration_Subargs
+        """
+
+        def _flags_code():
+            s = ""
+            if self.desc.get("optional", False):
+                s += "CMD_ARG_OPTIONAL|"
+            if self.desc.get("multiple", False):
+                s += "CMD_ARG_MULTIPLE|"
+            if self.desc.get("multiple_token", False):
+                assert self.desc.get("multiple", False)  # Sanity
+                s += "CMD_ARG_MULTIPLE_TOKEN|"
+            return s[:-1] if s else "CMD_ARG_NONE"
+
+        s = "\"%s\",%s,%d,%s,%s,%s,%s" % (
+            self.name,
+            ARG_TYPES[self.type],
+            self.desc.get("key_spec_index", -1),
+            get_optional_desc_string(self.desc, "token", force_uppercase=True),
+            get_optional_desc_string(self.desc, "summary"),
+            get_optional_desc_string(self.desc, "since"),
+            _flags_code(),
+        )
+        if "deprecated_since" in self.desc:
+            s += ",.deprecated_since=\"%s\"" % self.desc["deprecated_since"]
+        if self.subargs:
+            s += ",.subargs=%s" % self.subarg_table_name()
+
+        return s
+
+    def write_internal_structs(self, f):
+        if self.subargs:
+            for subarg in self.subargs:
+                subarg.write_internal_structs(f)
+
+            f.write("/* %s argument table */\n" % self.fullname())
+            f.write("struct redisCommandArg %s[] = {\n" % self.subarg_table_name())
+            for subarg in self.subargs:
+                f.write("{%s},\n" % subarg.struct_code())
+            f.write("{0}\n")
+            f.write("};\n\n")
+
+
+class Command(object):
+    def __init__(self, name, desc):
+        self.name = name.upper()
+        self.desc = desc
+        self.group = self.desc["group"]
+        self.key_specs = self.desc.get("key_specs", [])
+        self.subcommands = []
+        self.args = []
+        for arg_desc in self.desc.get("arguments", []):
+            self.args.append(Argument(self.fullname(), arg_desc))
+
+    def fullname(self):
+        return self.name.replace("-", "_").replace(":", "")
+
+    def return_types_table_name(self):
+        return "%s_ReturnInfo" % self.fullname().replace(" ", "_")
+
+    def subcommand_table_name(self):
+        assert self.subcommands
+        return "%s_Subcommands" % self.name
+
+    def history_table_name(self):
+        return "%s_History" % (self.fullname().replace(" ", "_"))
+
+    def tips_table_name(self):
+        return "%s_tips" % (self.fullname().replace(" ", "_"))
+
+    def arg_table_name(self):
+        return "%s_Args" % (self.fullname().replace(" ", "_"))
+
+    def struct_name(self):
+        return "%s_Command" % (self.fullname().replace(" ", "_"))
+
+    def history_code(self):
+        if not self.desc.get("history"):
+            return ""
+        s = ""
+        for tupl in self.desc["history"]:
+            s += "{\"%s\",\"%s\"},\n" % (tupl[0], tupl[1])
+        s += "{0}"
+        return s
+
+    def tips_code(self):
+        if not self.desc.get("command_tips"):
+            return ""
+        s = ""
+        for hint in self.desc["command_tips"]:
+            s += "\"%s\",\n" % hint.lower()
+        s += "NULL"
+        return s
+
+    def struct_code(self):
+        """
+        Output example:
+        "set","Set the string value of a key","O(1)","1.0.0",CMD_DOC_NONE,NULL,NULL,COMMAND_GROUP_STRING,SET_History,SET_tips,setCommand,-3,"write denyoom @string",{{"write read",KSPEC_BS_INDEX,.bs.index={1},KSPEC_FK_RANGE,.fk.range={0,1,0}}},.args=SET_Args
+        """
+
+        def _flags_code():
+            s = ""
+            for flag in self.desc.get("command_flags", []):
+                s += "CMD_%s|" % flag
+            return s[:-1] if s else 0
+
+        def _acl_categories_code():
+            s = ""
+            for cat in self.desc.get("acl_categories", []):
+                s += "ACL_CATEGORY_%s|" % cat
+            return s[:-1] if s else 0
+
+        def _doc_flags_code():
+            s = ""
+            for flag in self.desc.get("doc_flags", []):
+                s += "CMD_DOC_%s|" % flag
+            return s[:-1] if s else "CMD_DOC_NONE"
+
+        def _key_specs_code():
+            s = ""
+            for spec in self.key_specs:
+                s += "{%s}," % KeySpec(spec).struct_code()
+            return s[:-1]
+
+        s = "\"%s\",%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%d,%s,%s," % (
+            self.name.lower(),
+            get_optional_desc_string(self.desc, "summary"),
+            get_optional_desc_string(self.desc, "complexity"),
+            get_optional_desc_string(self.desc, "since"),
+            _doc_flags_code(),
+            get_optional_desc_string(self.desc, "replaced_by"),
+            get_optional_desc_string(self.desc, "deprecated_since"),
+            GROUPS[self.group],
+            self.history_table_name(),
+            self.tips_table_name(),
+            self.desc.get("function", "NULL"),
+            self.desc["arity"],
+            _flags_code(),
+            _acl_categories_code()
+        )
+
+        specs = _key_specs_code()
+        if specs:
+            s += "{%s}," % specs
+
+        if self.desc.get("get_keys_function"):
+            s += "%s," % self.desc["get_keys_function"]
+
+        if self.subcommands:
+            s += ".subcommands=%s," % self.subcommand_table_name()
+
+        if self.args:
+            s += ".args=%s," % self.arg_table_name()
+
+        return s[:-1]
+
+    def write_internal_structs(self, f):
+        if self.subcommands:
+            subcommand_list = sorted(self.subcommands, key=lambda cmd: cmd.name)
+            for subcommand in subcommand_list:
+                subcommand.write_internal_structs(f)
+
+            f.write("/* %s command table */\n" % self.fullname())
+            f.write("struct redisCommand %s[] = {\n" % self.subcommand_table_name())
+            for subcommand in subcommand_list:
+                f.write("{%s},\n" % subcommand.struct_code())
+            f.write("{0}\n")
+            f.write("};\n\n")
+
+        f.write("/********** %s ********************/\n\n" % self.fullname())
+
+        f.write("/* %s history */\n" % self.fullname())
+        code = self.history_code()
+        if code:
+            f.write("commandHistory %s[] = {\n" % self.history_table_name())
+            f.write("%s\n" % code)
+            f.write("};\n\n")
+        else:
+            f.write("#define %s NULL\n\n" % self.history_table_name())
+
+        f.write("/* %s tips */\n" % self.fullname())
+        code = self.tips_code()
+        if code:
+            f.write("const char *%s[] = {\n" % self.tips_table_name())
+            f.write("%s\n" % code)
+            f.write("};\n\n")
+        else:
+            f.write("#define %s NULL\n\n" % self.tips_table_name())
+
+        if self.args:
+            for arg in self.args:
+                arg.write_internal_structs(f)
+
+            f.write("/* %s argument table */\n" % self.fullname())
+            f.write("struct redisCommandArg %s[] = {\n" % self.arg_table_name())
+            for arg in self.args:
+                f.write("{%s},\n" % arg.struct_code())
+            f.write("{0}\n")
+            f.write("};\n\n")
+
+
+class Subcommand(Command):
+    def __init__(self, name, desc):
+        self.container_name = desc["container"].upper()
+        super(Subcommand, self).__init__(name, desc)
+
+    def fullname(self):
+        return "%s %s" % (self.container_name, self.name.replace("-", "_").replace(":", ""))
+
+
+def create_command(name, desc):
+    if desc.get("container"):
+        cmd = Subcommand(name.upper(), desc)
+        subcommands.setdefault(desc["container"].upper(), {})[name] = cmd
+    else:
+        cmd = Command(name.upper(), desc)
+        commands[name.upper()] = cmd
+
+
+# MAIN
+
+# Figure out where the sources are
+srcdir = os.path.abspath(os.path.dirname(os.path.abspath(__file__)) + "/../src")
+
+# Create all command objects
+print("Processing json files...")
+for filename in glob.glob('%s/commands/*.json' % srcdir):
+    with open(filename, "r") as f:
+        try:
+            d = json.load(f)
+            for name, desc in d.items():
+                create_command(name, desc)
+        except json.decoder.JSONDecodeError as err:
+            print("Error processing %s: %s" % (filename, err))
+            exit(1)
+
+# Link subcommands to containers
+print("Linking container command to subcommands...")
+for command in commands.values():
+    assert command.group
+    if command.name not in subcommands:
+        continue
+    for subcommand in subcommands[command.name].values():
+        assert not subcommand.group or subcommand.group == command.group
+        subcommand.group = command.group
+        command.subcommands.append(subcommand)
+
+check_command_error_counter = 0  # An error counter is used to count errors in command checking.
+
+print("Checking all commands...")
+for command in commands.values():
+    if not check_command_key_specs(command):
+        check_command_error_counter += 1
+
+if check_command_error_counter != 0:
+    print("Error: There are errors in the commands check, please check the above logs.")
+    exit(1)
+
+print("Generating commands.c...")
+with open("%s/commands.c" % srcdir, "w") as f:
+    f.write("/* Automatically generated by %s, do not edit. */\n\n" % os.path.basename(__file__))
+    f.write("#include \"server.h\"\n")
+    f.write(
+"""
+/* We have fabulous commands from
+ * the fantastic
+ * Redis Command Table! */\n
+"""
+    )
+
+    command_list = sorted(commands.values(), key=lambda cmd: (cmd.group, cmd.name))
+    for command in command_list:
+        command.write_internal_structs(f)
+
+    f.write("/* Main command table */\n")
+    f.write("struct redisCommand redisCommandTable[] = {\n")
+    curr_group = None
+    for command in command_list:
+        if curr_group != command.group:
+            curr_group = command.group
+            f.write("/* %s */\n" % curr_group)
+        f.write("{%s},\n" % command.struct_code())
+    f.write("{0}\n")
+    f.write("};\n")
+
+print("All done, exiting.")
diff --git a/utils/generate-command-help.rb b/utils/generate-command-help.rb
new file mode 100755
index 0000000..1042ce6
--- /dev/null
+++ b/utils/generate-command-help.rb
@@ -0,0 +1,151 @@
+#!/usr/bin/env ruby -w
+# Usage: generate-command-help.r [path/to/commands.json]
+#    or: generate-commands-json.py | generate-command-help.rb -
+#
+# Defaults to downloading commands.json from the redis-doc repo if not provided
+# or STDINed.
+
+GROUPS = [
+  "generic",
+  "string",
+  "list",
+  "set",
+  "sorted-set",
+  "hash",
+  "pubsub",
+  "transactions",
+  "connection",
+  "server",
+  "scripting",
+  "hyperloglog",
+  "cluster",
+  "geo",
+  "stream",
+  "bitmap"
+].freeze
+
+GROUPS_BY_NAME = Hash[*
+  GROUPS.each_with_index.map do |n,i|
+    [n,i]
+  end.flatten
+].freeze
+
+def argument arg
+  if "block" == arg["type"]
+    name = arg["arguments"].map do |entry|
+      argument entry
+    end.join " "
+  elsif "oneof" == arg["type"]
+    name = arg["arguments"].map do |entry|
+      argument entry
+    end.join "|"
+  elsif "pure-token" == arg["type"]
+    name = nil    # prepended later
+  else
+    name = arg["name"].is_a?(Array) ? arg["name"].join(" ") : arg["name"]
+  end
+  if arg["multiple"]
+    if arg["multiple_token"]
+      name = "#{name} [#{arg["token"]} #{name} ...]"
+    else
+      name = "#{name} [#{name} ...]"
+    end
+  end
+  if arg["token"]
+    name = [arg["token"], name].compact.join " "
+  end
+  if arg["optional"]
+    name = "[#{name}]"
+  end
+  name
+end
+
+def arguments command
+  return "" unless command["arguments"]
+  command["arguments"].map do |arg|
+    argument arg
+  end.join " "
+end
+
+def commands
+  return @commands if @commands
+
+  require "rubygems"
+  require "net/http"
+  require "net/https"
+  require "json"
+  require "uri"
+  if ARGV.length > 0
+    if ARGV[0] == '-'
+      data = STDIN.read
+    elsif FileTest.exist? ARGV[0]
+      data = File.read(ARGV[0])
+    else
+      raise Exception.new "File not found: #{ARGV[0]}"
+    end
+  else
+    url = URI.parse "https://raw.githubusercontent.com/redis/redis-doc/master/commands.json"
+    client = Net::HTTP.new url.host, url.port
+    client.use_ssl = true
+    response = client.get url.path
+    if !response.is_a?(Net::HTTPSuccess)
+      response.error!
+      return
+    else
+      data = response.body
+    end
+  end
+  @commands = JSON.parse(data)
+end
+
+def generate_groups
+  GROUPS.map do |n|
+    "\"#{n}\""
+  end.join(",\n    ");
+end
+
+def generate_commands
+  commands.to_a.sort do |x,y|
+    x[0] <=> y[0]
+  end.map do |key, command|
+    group = GROUPS_BY_NAME[command["group"]]
+    if group.nil?
+      STDERR.puts "Please update groups array in #{__FILE__}"
+      raise "Unknown group #{command["group"]}"
+    end
+
+    ret = <<-SPEC
+{ "#{key}",
+    "#{arguments(command)}",
+    "#{command["summary"]}",
+    #{group},
+    "#{command["since"]}" }
+    SPEC
+    ret.strip
+  end.join(",\n    ")
+end
+
+# Write to stdout
+puts <<-HELP_H
+/* Automatically generated by #{__FILE__}, do not edit. */
+
+#ifndef __REDIS_HELP_H
+#define __REDIS_HELP_H
+
+static char *commandGroups[] = {
+    #{generate_groups}
+};
+
+struct commandHelp {
+  char *name;
+  char *params;
+  char *summary;
+  int group;
+  char *since;
+} commandHelp[] = {
+    #{generate_commands}
+};
+
+#endif
+HELP_H
+
diff --git a/utils/generate-commands-json.py b/utils/generate-commands-json.py
new file mode 100755
index 0000000..23782ea
--- /dev/null
+++ b/utils/generate-commands-json.py
@@ -0,0 +1,136 @@
+#!/usr/bin/env python3
+import argparse
+import json
+import os
+import subprocess
+from collections import OrderedDict
+from sys import argv
+
+
+def convert_flags_to_boolean_dict(flags):
+    """Return a dict with a key set to `True` per element in the flags list."""
+    return {f: True for f in flags}
+
+
+def set_if_not_none_or_empty(dst, key, value):
+    """Set 'key' in 'dst' if 'value' is not `None` or an empty list."""
+    if value is not None and (type(value) is not list or len(value)):
+        dst[key] = value
+
+
+def convert_argument(arg):
+    """Transform an argument."""
+    arg.update(convert_flags_to_boolean_dict(arg.pop('flags', [])))
+    set_if_not_none_or_empty(arg, 'arguments',
+                             [convert_argument(x) for x in arg.pop('arguments', [])])
+    return arg
+
+
+def convert_keyspec(spec):
+    """Transform a key spec."""
+    spec.update(convert_flags_to_boolean_dict(spec.pop('flags', [])))
+    return spec
+
+
+def convert_entry_to_objects_array(cmd, docs):
+    """Transform the JSON output of `COMMAND` to a friendlier format.
+
+    cmd is the output of `COMMAND` as follows:
+    1. Name (lower case, e.g. "lolwut")
+    2. Arity
+    3. Flags
+    4-6. First/last/step key specification (deprecated as of Redis v7.0)
+    7. ACL categories
+    8. hints (as of Redis 7.0)
+    9. key-specs (as of Redis 7.0)
+    10. subcommands (as of Redis 7.0)
+
+    docs is the output of `COMMAND DOCS`, which holds a map of additional metadata
+
+    This returns a list with a dict for the command and per each of its
+    subcommands. Each dict contains one key, the command's full name, with a
+    value of a dict that's set with the command's properties and meta
+    information."""
+    assert len(cmd) >= 9
+    obj = {}
+    rep = [obj]
+    name = cmd[0].upper()
+    arity = cmd[1]
+    command_flags = cmd[2]
+    acl_categories = cmd[6]
+    hints = cmd[7]
+    keyspecs = cmd[8]
+    subcommands = cmd[9] if len(cmd) > 9 else []
+    key = name.replace('|', ' ')
+
+    subcommand_docs = docs.pop('subcommands', [])
+    rep.extend([convert_entry_to_objects_array(x, subcommand_docs[x[0]])[0] for x in subcommands])
+
+    # The command's value is ordered so the interesting stuff that we care about
+    # is at the start. Optional `None` and empty list values are filtered out.
+    value = OrderedDict()
+    value['summary'] = docs.pop('summary')
+    value['since'] = docs.pop('since')
+    value['group'] = docs.pop('group')
+    set_if_not_none_or_empty(value, 'complexity', docs.pop('complexity', None))
+    set_if_not_none_or_empty(value, 'deprecated_since', docs.pop('deprecated_since', None))
+    set_if_not_none_or_empty(value, 'replaced_by', docs.pop('replaced_by', None))
+    set_if_not_none_or_empty(value, 'history', docs.pop('history', []))
+    set_if_not_none_or_empty(value, 'acl_categories', acl_categories)
+    value['arity'] = arity
+    set_if_not_none_or_empty(value, 'key_specs',
+                             [convert_keyspec(x) for x in keyspecs])
+    set_if_not_none_or_empty(value, 'arguments',
+                             [convert_argument(x) for x in docs.pop('arguments', [])])
+    set_if_not_none_or_empty(value, 'command_flags', command_flags)
+    set_if_not_none_or_empty(value, 'doc_flags', docs.pop('doc_flags', []))
+    set_if_not_none_or_empty(value, 'hints', hints)
+
+    # All remaining docs key-value tuples, if any, are appended to the command
+    # to be future-proof.
+    while len(docs) > 0:
+        (k, v) = docs.popitem()
+        value[k] = v
+
+    obj[key] = value
+    return rep
+
+
+# Figure out where the sources are
+srcdir = os.path.abspath(os.path.dirname(os.path.abspath(__file__)) + "/../src")
+
+# MAIN
+if __name__ == '__main__':
+    opts = {
+        'description': 'Transform the output from `redis-cli --json` using COMMAND and COMMAND DOCS to a single commands.json format.',
+        'epilog': f'Usage example: {argv[0]} --cli src/redis-cli --port 6379 > commands.json'
+    }
+    parser = argparse.ArgumentParser(**opts)
+    parser.add_argument('--host', type=str, default='localhost')
+    parser.add_argument('--port', type=int, default=6379)
+    parser.add_argument('--cli', type=str, default='%s/redis-cli' % srcdir)
+    args = parser.parse_args()
+
+    payload = OrderedDict()
+    cmds = []
+
+    p = subprocess.Popen([args.cli, '-h', args.host, '-p', str(args.port), '--json', 'command'], stdout=subprocess.PIPE)
+    stdout, stderr = p.communicate()
+    commands = json.loads(stdout)
+
+    p = subprocess.Popen([args.cli, '-h', args.host, '-p', str(args.port), '--json', 'command', 'docs'],
+                         stdout=subprocess.PIPE)
+    stdout, stderr = p.communicate()
+    docs = json.loads(stdout)
+
+    for entry in commands:
+        cmd = convert_entry_to_objects_array(entry, docs[entry[0]])
+        cmds.extend(cmd)
+
+    # The final output is a dict of all commands, ordered by name.
+    cmds.sort(key=lambda x: list(x.keys())[0])
+    for cmd in cmds:
+        name = list(cmd.keys())[0]
+        payload[name] = cmd[name]
+
+    print(json.dumps(payload, indent=4))
diff --git a/utils/generate-module-api-doc.rb b/utils/generate-module-api-doc.rb
new file mode 100755
index 0000000..8829434
--- /dev/null
+++ b/utils/generate-module-api-doc.rb
@@ -0,0 +1,205 @@
+#!/usr/bin/env ruby
+# coding: utf-8
+# gendoc.rb -- Converts the top-comments inside module.c to modules API
+#              reference documentation in markdown format.
+
+# Convert the C comment to markdown
+def markdown(s)
+    s = s.gsub(/\*\/$/,"")
+    s = s.gsub(/^ ?\* ?/,"")
+    s = s.gsub(/^\/\*\*? ?/,"")
+    s.chop! while s[-1] == "\n" || s[-1] == " "
+    lines = s.split("\n")
+    newlines = []
+    # Fix some markdown
+    lines.each{|l|
+        # Rewrite RM_Xyz() to RedisModule_Xyz().
+        l = l.gsub(/(?<![A-Z_])RM_(?=[A-Z])/, 'RedisModule_')
+        # Fix more markdown, except in code blocks indented by 4 spaces, which we
+        # don't want to mess with.
+        if not l.start_with?('    ')
+            # Add backquotes around RedisModule functions and type where missing.
+            l = l.gsub(/(?<!`)RedisModule[A-z]+(?:\*?\(\))?/){|x| "`#{x}`"}
+            # Add backquotes around c functions like malloc() where missing.
+            l = l.gsub(/(?<![`A-z.])[a-z_]+\(\)/, '`\0`')
+            # Add backquotes around macro and var names containing underscores.
+            l = l.gsub(/(?<![`A-z\*])[A-Za-z]+_[A-Za-z0-9_]+/){|x| "`#{x}`"}
+            # Link URLs preceded by space or newline (not already linked)
+            l = l.gsub(/(^| )(https?:\/\/[A-Za-z0-9_\/\.\-]+[A-Za-z0-9\/])/,
+                       '\1[\2](\2)')
+            # Replace double-dash with unicode ndash
+            l = l.gsub(/ -- /, ' – ')
+        end
+        # Link function names to their definition within the page
+        l = l.gsub(/`(RedisModule_[A-z0-9]+)[()]*`/) {|x|
+            $index[$1] ? "[#{x}](\##{$1})" : x
+        }
+        newlines << l
+    }
+    return newlines.join("\n")
+end
+
+# Linebreak a prototype longer than 80 characters on the commas, but only
+# between balanced parentheses so that we don't linebreak args which are
+# function pointers, and then aligning each arg under each other.
+def linebreak_proto(proto, indent)
+    if proto.bytesize <= 80
+        return proto
+    end
+    parts = proto.split(/,\s*/);
+    if parts.length == 1
+        return proto;
+    end
+    align_pos = proto.index("(") + 1;
+    align = " " * align_pos
+    result = parts.shift;
+    bracket_balance = 0;
+    parts.each{|part|
+        if bracket_balance == 0
+            result += ",\n" + indent + align
+        else
+            result += ", "
+        end
+        result += part
+        bracket_balance += part.count("(") - part.count(")")
+    }
+    return result;
+end
+
+# Given the source code array and the index at which an exported symbol was
+# detected, extracts and outputs the documentation.
+def docufy(src,i)
+    m = /RM_[A-z0-9]+/.match(src[i])
+    name = m[0]
+    name = name.sub("RM_","RedisModule_")
+    proto = src[i].sub("{","").strip+";\n"
+    proto = proto.sub("RM_","RedisModule_")
+    proto = linebreak_proto(proto, "    ");
+    # Add a link target with the function name. (We don't trust the exact id of
+    # the generated one, which depends on the Markdown implementation.)
+    puts "<span id=\"#{name}\"></span>\n\n"
+    puts "### `#{name}`\n\n"
+    puts "    #{proto}\n"
+    puts "**Available since:** #{$since[name] or "unreleased"}\n\n"
+    comment = ""
+    while true
+        i = i-1
+        comment = src[i]+comment
+        break if src[i] =~ /\/\*/
+    end
+    comment = markdown(comment)
+    puts comment+"\n\n"
+end
+
+# Print a comment from line until */ is found, as markdown.
+def section_doc(src, i)
+    name = get_section_heading(src, i)
+    comment = "<span id=\"#{section_name_to_id(name)}\"></span>\n\n"
+    while true
+         # append line, except if it's a horizontal divider
+        comment = comment + src[i] if src[i] !~ /^[\/ ]?\*{1,2} ?-{50,}/
+        break if src[i] =~ /\*\//
+        i = i+1
+    end
+    comment = markdown(comment)
+    puts comment+"\n\n"
+end
+
+# generates an id suitable for links within the page
+def section_name_to_id(name)
+    return "section-" +
+           name.strip.downcase.gsub(/[^a-z0-9]+/, '-').gsub(/^-+|-+$/, '')
+end
+
+# Returns the name of the first section heading in the comment block for which
+# is_section_doc(src, i) is true
+def get_section_heading(src, i)
+    if src[i] =~ /^\/\*\*? \#+ *(.*)/
+        heading = $1
+    elsif src[i+1] =~ /^ ?\* \#+ *(.*)/
+        heading = $1
+    end
+    return heading.gsub(' -- ', ' – ')
+end
+
+# Returns true if the line is the start of a generic documentation section. Such
+# section must start with the # symbol, i.e. a markdown heading, on the first or
+# the second line.
+def is_section_doc(src, i)
+    return src[i] =~ /^\/\*\*? \#/ ||
+           (src[i] =~ /^\/\*/ && src[i+1] =~ /^ ?\* \#/)
+end
+
+def is_func_line(src, i)
+  line = src[i]
+  return line =~ /RM_/ &&
+         line[0] != ' ' && line[0] != '#' && line[0] != '/' &&
+         src[i-1] =~ /\*\//
+end
+
+puts "---\n"
+puts "title: \"Modules API reference\"\n"
+puts "linkTitle: \"API reference\"\n"
+puts "weight: 1\n"
+puts "description: >\n"
+puts "    Reference for the Redis Modules API\n"
+puts "aliases:\n"
+puts "    - /topics/modules-api-ref\n"
+puts "---\n"
+puts "\n"
+puts "<!-- This file is generated from module.c using\n"
+puts "     utils/generate-module-api-doc.rb -->\n\n"
+src = File.open(File.dirname(__FILE__) ++ "/../src/module.c").to_a
+
+# Build function index
+$index = {}
+src.each_with_index do |line,i|
+    if is_func_line(src, i)
+        line =~ /RM_([A-z0-9]+)/
+        name = "RedisModule_#{$1}"
+        $index[name] = true
+    end
+end
+
+# Populate the 'since' map (name => version) if we're in a git repo.
+$since = {}
+git_dir = File.dirname(__FILE__) ++ "/../.git"
+if File.directory?(git_dir) && `which git` != ""
+    `git --git-dir="#{git_dir}" tag --sort=v:refname`.each_line do |version|
+        next if version !~ /^(\d+)\.\d+\.\d+?$/ || $1.to_i < 4
+        version.chomp!
+        `git --git-dir="#{git_dir}" cat-file blob "#{version}:src/module.c"`.each_line do |line|
+            if line =~ /^\w.*[ \*]RM_([A-z0-9]+)/
+                name = "RedisModule_#{$1}"
+                if ! $since[name]
+                    $since[name] = version
+                end
+            end
+        end
+    end
+end
+
+# Print TOC
+puts "## Sections\n\n"
+src.each_with_index do |_line,i|
+    if is_section_doc(src, i)
+        name = get_section_heading(src, i)
+        puts "* [#{name}](\##{section_name_to_id(name)})\n"
+    end
+end
+puts "* [Function index](#section-function-index)\n\n"
+
+# Docufy: Print function prototype and markdown docs
+src.each_with_index do |_line,i|
+    if is_func_line(src, i)
+        docufy(src, i)
+    elsif is_section_doc(src, i)
+        section_doc(src, i)
+    end
+end
+
+# Print function index
+puts "<span id=\"section-function-index\"></span>\n\n"
+puts "## Function index\n\n"
+$index.keys.sort.each{|x| puts "* [`#{x}`](\##{x})\n"}
+puts "\n"
diff --git a/utils/graphs/commits-over-time/README.md b/utils/graphs/commits-over-time/README.md
new file mode 100644
index 0000000..b28019e
--- /dev/null
+++ b/utils/graphs/commits-over-time/README.md
@@ -0,0 +1,16 @@
+This Tcl script is what I used in order to generate the graph you
+can find at http://antirez.com/news/98. It's really quick & dirty, more
+a trow away program than anything else, but probably could be reused or
+modified in the future in order to visualize other similar data or an
+updated version of the same data.
+
+The usage is trivial:
+
+    ./genhtml.tcl > output.html
+
+The generated HTML is quite broken but good enough to grab a screenshot
+from the browser. Feel free to improve it if you got time / interest.
+
+Note that the code filtering the tags, and the hardcoded branch name, does
+not make the script, as it is, able to analyze a different repository.
+However the changes needed are trivial.
diff --git a/utils/graphs/commits-over-time/genhtml.tcl b/utils/graphs/commits-over-time/genhtml.tcl
new file mode 100755
index 0000000..c4b4e09
--- /dev/null
+++ b/utils/graphs/commits-over-time/genhtml.tcl
@@ -0,0 +1,96 @@
+#!/usr/bin/env tclsh
+
+# Load commits history as "sha1 unixtime".
+set commits [exec git log unstable {--pretty="%H %at"}]
+set raw_tags [exec git tag]
+
+# Load all the tags that are about stable releases.
+foreach tag $raw_tags {
+    if {[string match v*-stable $tag]} {
+        set tag [string range $tag 1 end-7]
+        puts $tag
+    }
+    if {[regexp {^[0-9]+.[0-9]+.[0-9]+$} $tag]} {
+        lappend tags $tag
+    }
+}
+
+# For each tag, create a list of "name unixtime"
+foreach tag $tags {
+    set taginfo [exec git log $tag -n 1 "--pretty=\"$tag %at\""]
+    set taginfo [string trim $taginfo {"}]
+    lappend labels $taginfo
+}
+
+# For each commit, check the amount of code changed and create an array
+# mapping the commit to the number of lines affected.
+foreach c $commits {
+    set stat [exec git show --oneline --numstat [lindex $c 0]]
+    set linenum 0
+    set affected 0
+    foreach line [split $stat "\n"] {
+        incr linenum
+        if {$linenum == 1 || [string match *deps/* $line]} continue
+        if {[catch {llength $line} numfields]} continue
+        if {$numfields == 0} continue
+        catch {
+            incr affected [lindex $line 0]
+            incr affected [lindex $line 1]
+        }
+    }
+    set commit_to_affected([lindex $c 0]) $affected
+}
+
+set base_time [lindex [lindex $commits end] 1]
+puts [clock format $base_time]
+
+# Generate a graph made of HTML DIVs.
+puts {<html>
+<style>
+.box {
+    position:absolute;
+    width:10px;
+    height:5px;
+    border:1px black solid;
+    background-color:#44aa33;
+    opacity: 0.04;
+}
+.label {
+    position:absolute;
+    background-color:#dddddd;
+    font-family:helvetica;
+    font-size:12px;
+    padding:2px;
+    color:#666;
+    border:1px #aaa solid;
+    border-radius: 5px;
+}
+#outer {
+    position:relative;
+    width:1500;
+    height:500;
+    border:1px #aaa solid;
+}
+</style>
+<div id="outer">
+}
+foreach c $commits {
+    set sha [lindex $c 0]
+    set t [expr {([lindex $c 1]-$base_time)/(3600*24*2)}]
+    set affected [expr $commit_to_affected($sha)]
+    set left $t
+    set height [expr {log($affected)*20}]
+    puts "<div class=\"box\" style=\"left:$left; bottom:0; height:$height\"></div>"
+}
+
+set bottom -30
+foreach l $labels {
+    set name [lindex $l 0]
+    set t [expr {([lindex $l 1]-$base_time)/(3600*24*2)}]
+    set left $t
+    if {$left < 0} continue
+    incr bottom -20
+    if  {$bottom == -210} {set bottom -30}
+    puts "<div class=\"label\" style=\"left:$left; bottom:$bottom\">$name</div>"
+}
+puts {</div></html>}
diff --git a/utils/hyperloglog/.gitignore b/utils/hyperloglog/.gitignore
new file mode 100644
index 0000000..2211df6
--- /dev/null
+++ b/utils/hyperloglog/.gitignore
@@ -0,0 +1 @@
+*.txt
diff --git a/utils/hyperloglog/hll-err.rb b/utils/hyperloglog/hll-err.rb
new file mode 100644
index 0000000..2c71ac5
--- /dev/null
+++ b/utils/hyperloglog/hll-err.rb
@@ -0,0 +1,27 @@
+# hll-err.rb - Copyright (C) 2014 Salvatore Sanfilippo
+# BSD license, See the COPYING file for more information.
+#
+# Check error of HyperLogLog Redis implementation for different set sizes.
+
+require 'rubygems'
+require 'redis'
+require 'digest/sha1'
+
+r = Redis.new
+r.del('hll')
+i = 0
+while true do
+    100.times {
+        elements = []
+        1000.times {
+            ele = Digest::SHA1.hexdigest(i.to_s)
+            elements << ele
+            i += 1
+        }
+        r.pfadd('hll',elements)
+    }
+    approx = r.pfcount('hll')
+    abs_err = (approx-i).abs
+    rel_err = 100.to_f*abs_err/i
+    puts "#{i} vs #{approx}: #{rel_err}%"
+end
diff --git a/utils/hyperloglog/hll-gnuplot-graph.rb b/utils/hyperloglog/hll-gnuplot-graph.rb
new file mode 100644
index 0000000..6c7596d
--- /dev/null
+++ b/utils/hyperloglog/hll-gnuplot-graph.rb
@@ -0,0 +1,88 @@
+# hll-err.rb - Copyright (C) 2014 Salvatore Sanfilippo
+# BSD license, See the COPYING file for more information.
+#
+# This program is suited to output average and maximum errors of
+# the Redis HyperLogLog implementation in a format suitable to print
+# graphs using gnuplot.
+
+require 'rubygems'
+require 'redis'
+require 'digest/sha1'
+
+# Generate an array of [cardinality,relative_error] pairs
+# in the 0 - max range, with the specified step.
+#
+# 'r' is the Redis object used to perform the queries.
+# 'seed' must be different every time you want a test performed
+# with a different set. The function guarantees that if 'seed' is the
+# same, exactly the same dataset is used, and when it is different,
+# a totally unrelated different data set is used (without any common
+# element in practice).
+def run_experiment(r,seed,max,step)
+    r.del('hll')
+    i = 0
+    samples = []
+    step = 1000 if step > 1000
+    while i < max do
+        elements = []
+        step.times {
+            ele = Digest::SHA1.hexdigest(i.to_s+seed.to_s)
+            elements << ele
+            i += 1
+        }
+        r.pfadd('hll',elements)
+        approx = r.pfcount('hll')
+        err = approx-i
+        rel_err = 100.to_f*err/i
+        samples << [i,rel_err]
+    end
+    samples
+end
+
+def filter_samples(numsets,max,step,filter)
+    r = Redis.new
+    dataset = {}
+    (0...numsets).each{|i|
+        dataset[i] = run_experiment(r,i,max,step)
+        STDERR.puts "Set #{i}"
+    }
+    dataset[0].each_with_index{|ele,index|
+        if filter == :max
+            card=ele[0]
+            err=ele[1].abs
+            (1...numsets).each{|i|
+                err = dataset[i][index][1] if err < dataset[i][index][1]
+            }
+            puts "#{card} #{err}"
+        elsif filter == :avg
+            card=ele[0]
+            err = 0
+            (0...numsets).each{|i|
+                err += dataset[i][index][1]
+            }
+            err /= numsets
+            puts "#{card} #{err}"
+        elsif filter == :absavg
+            card=ele[0]
+            err = 0
+            (0...numsets).each{|i|
+                err += dataset[i][index][1].abs
+            }
+            err /= numsets
+            puts "#{card} #{err}"
+        elsif filter == :all
+            (0...numsets).each{|i|
+                card,err = dataset[i][index]
+                puts "#{card} #{err}"
+            }
+        else
+            raise "Unknown filter #{filter}"
+        end
+    }
+end
+
+if ARGV.length != 4
+    puts "Usage: hll-gnuplot-graph <samples> <max> <step> (max|avg|absavg|all)"
+    exit 1
+end
+filter_samples(ARGV[0].to_i,ARGV[1].to_i,ARGV[2].to_i,ARGV[3].to_sym)
diff --git a/utils/install_server.sh b/utils/install_server.sh
new file mode 100755
index 0000000..efda7da
--- /dev/null
+++ b/utils/install_server.sh
@@ -0,0 +1,291 @@
+#!/bin/sh
+
+# Copyright 2011 Dvir Volk <dvirsk at gmail dot com>. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+#   1. Redistributions of source code must retain the above copyright notice,
+#   this list of conditions and the following disclaimer.
+#
+#   2. Redistributions in binary form must reproduce the above copyright
+#   notice, this list of conditions and the following disclaimer in the
+#   documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+# WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+# EVENT SHALL Dvir Volk OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
+# OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+# EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+################################################################################
+#
+# Service installer for redis server, runs interactively by default.
+#
+# To run this script non-interactively (for automation/provisioning purposes),
+# feed the variables into the script. Any missing variables will be prompted!
+# Tip: Environment variables also support command substitution (see REDIS_EXECUTABLE)
+#
+# Example:
+#
+# sudo REDIS_PORT=1234 \
+# 		 REDIS_CONFIG_FILE=/etc/redis/1234.conf \
+# 		 REDIS_LOG_FILE=/var/log/redis_1234.log \
+# 		 REDIS_DATA_DIR=/var/lib/redis/1234 \
+# 		 REDIS_EXECUTABLE=`command -v redis-server` ./utils/install_server.sh
+#
+# This generates a redis config file and an /etc/init.d script, and installs them.
+#
+# /!\ This script should be run as root
+#
+# NOTE: This script will not work on Mac OSX.
+#       It supports Debian and Ubuntu Linux.
+#
+################################################################################
+
+die () {
+	echo "ERROR: $1. Aborting!"
+	exit 1
+}
+
+
+#Absolute path to this script
+SCRIPT=$(readlink -f $0)
+#Absolute path this script is in
+SCRIPTPATH=$(dirname $SCRIPT)
+
+#Initial defaults
+_REDIS_PORT=6379
+_MANUAL_EXECUTION=false
+
+echo "Welcome to the redis service installer"
+echo "This script will help you easily set up a running redis server"
+echo
+
+#check for root user
+if [ "$(id -u)" -ne 0 ] ; then
+	echo "You must run this script as root. Sorry!"
+	exit 1
+fi
+
+#bail if this system is managed by systemd
+_pid_1_exe="$(readlink -f /proc/1/exe)"
+if [ "${_pid_1_exe##*/}" = systemd ]
+then
+	echo "This systems seems to use systemd."
+	echo "Please take a look at the provided example service unit files in this directory, and adapt and install them. Sorry!"
+	exit 1
+fi
+unset _pid_1_exe
+
+if ! echo $REDIS_PORT | egrep -q '^[0-9]+$' ; then
+	_MANUAL_EXECUTION=true
+	#Read the redis port
+	read  -p "Please select the redis port for this instance: [$_REDIS_PORT] " REDIS_PORT
+	if ! echo $REDIS_PORT | egrep -q '^[0-9]+$' ; then
+		echo "Selecting default: $_REDIS_PORT"
+		REDIS_PORT=$_REDIS_PORT
+	fi
+fi
+
+if [ -z "$REDIS_CONFIG_FILE" ] ; then
+	_MANUAL_EXECUTION=true
+	#read the redis config file
+	_REDIS_CONFIG_FILE="/etc/redis/$REDIS_PORT.conf"
+	read -p "Please select the redis config file name [$_REDIS_CONFIG_FILE] " REDIS_CONFIG_FILE
+	if [ -z "$REDIS_CONFIG_FILE" ] ; then
+		REDIS_CONFIG_FILE=$_REDIS_CONFIG_FILE
+		echo "Selected default - $REDIS_CONFIG_FILE"
+	fi
+fi
+
+if [ -z "$REDIS_LOG_FILE" ] ; then
+	_MANUAL_EXECUTION=true
+	#read the redis log file path
+	_REDIS_LOG_FILE="/var/log/redis_$REDIS_PORT.log"
+	read -p "Please select the redis log file name [$_REDIS_LOG_FILE] " REDIS_LOG_FILE
+	if [ -z "$REDIS_LOG_FILE" ] ; then
+		REDIS_LOG_FILE=$_REDIS_LOG_FILE
+		echo "Selected default - $REDIS_LOG_FILE"
+	fi
+fi
+
+if [ -z "$REDIS_DATA_DIR" ] ; then
+	_MANUAL_EXECUTION=true
+	#get the redis data directory
+	_REDIS_DATA_DIR="/var/lib/redis/$REDIS_PORT"
+	read -p "Please select the data directory for this instance [$_REDIS_DATA_DIR] " REDIS_DATA_DIR
+	if [ -z "$REDIS_DATA_DIR" ] ; then
+		REDIS_DATA_DIR=$_REDIS_DATA_DIR
+		echo "Selected default - $REDIS_DATA_DIR"
+	fi
+fi
+
+if [ ! -x "$REDIS_EXECUTABLE" ] ; then
+	_MANUAL_EXECUTION=true
+	#get the redis executable path
+	_REDIS_EXECUTABLE=`command -v redis-server`
+	read -p "Please select the redis executable path [$_REDIS_EXECUTABLE] " REDIS_EXECUTABLE
+	if [ ! -x "$REDIS_EXECUTABLE" ] ; then
+		REDIS_EXECUTABLE=$_REDIS_EXECUTABLE
+
+		if [ ! -x "$REDIS_EXECUTABLE" ] ; then
+			echo "Mmmmm...  it seems like you don't have a redis executable. Did you run make install yet?"
+			exit 1
+		fi
+	fi
+fi
+
+#check the default for redis cli
+CLI_EXEC=`command -v redis-cli`
+if [ -z "$CLI_EXEC" ] ; then
+	CLI_EXEC=`dirname $REDIS_EXECUTABLE`"/redis-cli"
+fi
+
+echo "Selected config:"
+
+echo "Port           : $REDIS_PORT"
+echo "Config file    : $REDIS_CONFIG_FILE"
+echo "Log file       : $REDIS_LOG_FILE"
+echo "Data dir       : $REDIS_DATA_DIR"
+echo "Executable     : $REDIS_EXECUTABLE"
+echo "Cli Executable : $CLI_EXEC"
+
+if $_MANUAL_EXECUTION == true ; then
+	read -p "Is this ok? Then press ENTER to go on or Ctrl-C to abort." _UNUSED_
+fi
+
+mkdir -p `dirname "$REDIS_CONFIG_FILE"` || die "Could not create redis config directory"
+mkdir -p `dirname "$REDIS_LOG_FILE"` || die "Could not create redis log dir"
+mkdir -p "$REDIS_DATA_DIR" || die "Could not create redis data directory"
+
+#render the templates
+TMP_FILE="/tmp/${REDIS_PORT}.conf"
+DEFAULT_CONFIG="${SCRIPTPATH}/../redis.conf"
+INIT_TPL_FILE="${SCRIPTPATH}/redis_init_script.tpl"
+INIT_SCRIPT_DEST="/etc/init.d/redis_${REDIS_PORT}"
+PIDFILE="/var/run/redis_${REDIS_PORT}.pid"
+
+if [ ! -f "$DEFAULT_CONFIG" ]; then
+	echo "Mmmmm... the default config is missing. Did you switch to the utils directory?"
+	exit 1
+fi
+
+#Generate config file from the default config file as template
+#changing only the stuff we're controlling from this script
+echo "## Generated by install_server.sh ##" > $TMP_FILE
+
+read -r SED_EXPR <<-EOF
+s#^port .\+#port ${REDIS_PORT}#; \
+s#^logfile .\+#logfile ${REDIS_LOG_FILE}#; \
+s#^dir .\+#dir ${REDIS_DATA_DIR}#; \
+s#^pidfile .\+#pidfile ${PIDFILE}#; \
+s#^daemonize no#daemonize yes#;
+EOF
+sed "$SED_EXPR" $DEFAULT_CONFIG >> $TMP_FILE
+
+#cat $TPL_FILE | while read line; do eval "echo \"$line\"" >> $TMP_FILE; done
+cp $TMP_FILE $REDIS_CONFIG_FILE || die "Could not write redis config file $REDIS_CONFIG_FILE"
+
+#Generate sample script from template file
+rm -f $TMP_FILE
+
+#we hard code the configs here to avoid issues with templates containing env vars
+#kinda lame but works!
+REDIS_INIT_HEADER=\
+"#!/bin/sh\n
+#Configurations injected by install_server below....\n\n
+EXEC=$REDIS_EXECUTABLE\n
+CLIEXEC=$CLI_EXEC\n
+PIDFILE=\"$PIDFILE\"\n
+CONF=\"$REDIS_CONFIG_FILE\"\n\n
+REDISPORT=\"$REDIS_PORT\"\n\n
+###############\n\n"
+
+REDIS_CHKCONFIG_INFO=\
+"# REDHAT chkconfig header\n\n
+# chkconfig: - 58 74\n
+# description: redis_${REDIS_PORT} is the redis daemon.\n
+### BEGIN INIT INFO\n
+# Provides: redis_6379\n
+# Required-Start: \$network \$local_fs \$remote_fs\n
+# Required-Stop: \$network \$local_fs \$remote_fs\n
+# Default-Start: 2 3 4 5\n
+# Default-Stop: 0 1 6\n
+# Should-Start: \$syslog \$named\n
+# Should-Stop: \$syslog \$named\n
+# Short-Description: start and stop redis_${REDIS_PORT}\n
+# Description: Redis daemon\n
+### END INIT INFO\n\n"
+
+if command -v chkconfig >/dev/null; then
+	#if we're a box with chkconfig on it we want to include info for chkconfig
+	echo "$REDIS_INIT_HEADER" "$REDIS_CHKCONFIG_INFO" > $TMP_FILE && cat $INIT_TPL_FILE >> $TMP_FILE || die "Could not write init script to $TMP_FILE"
+else
+	#combine the header and the template (which is actually a static footer)
+	echo "$REDIS_INIT_HEADER" > $TMP_FILE && cat $INIT_TPL_FILE >> $TMP_FILE || die "Could not write init script to $TMP_FILE"
+fi
+
+###
+# Generate sample script from template file
+# - No need to check which system we are on. The init info are comments and
+#   do not interfere with update_rc.d systems. Additionally:
+#     Ubuntu/debian by default does not come with chkconfig, but does issue a
+#     warning if init info is not available.
+
+cat > ${TMP_FILE} <<EOT
+#!/bin/sh
+#Configurations injected by install_server below....
+
+EXEC=$REDIS_EXECUTABLE
+CLIEXEC=$CLI_EXEC
+PIDFILE=$PIDFILE
+CONF="$REDIS_CONFIG_FILE"
+REDISPORT="$REDIS_PORT"
+###############
+# SysV Init Information
+# chkconfig: - 58 74
+# description: redis_${REDIS_PORT} is the redis daemon.
+### BEGIN INIT INFO
+# Provides: redis_${REDIS_PORT}
+# Required-Start: \$network \$local_fs \$remote_fs
+# Required-Stop: \$network \$local_fs \$remote_fs
+# Default-Start: 2 3 4 5
+# Default-Stop: 0 1 6
+# Should-Start: \$syslog \$named
+# Should-Stop: \$syslog \$named
+# Short-Description: start and stop redis_${REDIS_PORT}
+# Description: Redis daemon
+### END INIT INFO
+
+EOT
+cat ${INIT_TPL_FILE} >> ${TMP_FILE}
+
+#copy to /etc/init.d
+cp $TMP_FILE $INIT_SCRIPT_DEST && \
+	chmod +x $INIT_SCRIPT_DEST || die "Could not copy redis init script to  $INIT_SCRIPT_DEST"
+echo "Copied $TMP_FILE => $INIT_SCRIPT_DEST"
+
+#Install the service
+echo "Installing service..."
+if command -v chkconfig >/dev/null 2>&1; then
+	# we're chkconfig, so lets add to chkconfig and put in runlevel 345
+	chkconfig --add redis_${REDIS_PORT} && echo "Successfully added to chkconfig!"
+	chkconfig --level 345 redis_${REDIS_PORT} on && echo "Successfully added to runlevels 345!"
+elif command -v update-rc.d >/dev/null 2>&1; then
+	#if we're not a chkconfig box assume we're able to use update-rc.d
+	update-rc.d redis_${REDIS_PORT} defaults && echo "Success!"
+else
+	echo "No supported init tool found."
+fi
+
+/etc/init.d/redis_$REDIS_PORT start || die "Failed starting service..."
+
+#tada
+echo "Installation successful!"
+exit 0
diff --git a/utils/lru/README b/utils/lru/README
new file mode 100644
index 0000000..f043b29
--- /dev/null
+++ b/utils/lru/README
@@ -0,0 +1,19 @@
+The test-lru.rb program can be used in order to check the behavior of the
+Redis approximated LRU algorithm against the theoretical output of true
+LRU algorithm.
+
+In order to use the program you need to recompile Redis setting the define
+REDIS_LRU_CLOCK_RESOLUTION to 1, by editing the file server.h.
+This allows to execute the program in a fast way since the 1 ms resolution
+is enough for all the objects to have a different enough time stamp during
+the test.
+
+The program is executed like this:
+
+    ruby test-lru.rb /tmp/lru.html
+
+You can optionally specify a number of times to run, so that the program
+will output averages of different runs, by adding an additional argument.
+For instance in order to run the test 10 times use:
+
+    ruby test-lru.rb /tmp/lru.html 10
diff --git a/utils/lru/lfu-simulation.c b/utils/lru/lfu-simulation.c
new file mode 100644
index 0000000..60105e5
--- /dev/null
+++ b/utils/lru/lfu-simulation.c
@@ -0,0 +1,158 @@
+#include <stdio.h>
+#include <time.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+int decr_every = 1;
+int keyspace_size = 1000000;
+time_t switch_after = 30; /* Switch access pattern after N seconds. */
+
+struct entry {
+    /* Field that the LFU Redis implementation will have (we have
+     * 24 bits of total space in the object->lru field). */
+    uint8_t counter;    /* Logarithmic counter. */
+    uint16_t decrtime;  /* (Reduced precision) time of last decrement. */
+
+    /* Fields only useful for visualization. */
+    uint64_t hits;      /* Number of real accesses. */
+    time_t ctime;       /* Key creation time. */
+};
+
+#define to_16bit_minutes(x) ((x/60) & 65535)
+#define LFU_INIT_VAL 5
+
+/* Compute the difference in minutes between two 16 bit minutes times
+ * obtained with to_16bit_minutes(). Since they can wrap around if
+ * we detect the overflow we account for it as if the counter wrapped
+ * a single time. */
+uint16_t minutes_diff(uint16_t now, uint16_t prev) {
+    if (now >= prev) return now-prev;
+    return 65535-prev+now;
+}
+
+/* Increment a counter logarithmically: the greatest is its value, the
+ * less likely is that the counter is really incremented.
+ * The maximum value of the counter is saturated at 255. */
+uint8_t log_incr(uint8_t counter) {
+    if (counter == 255) return counter;
+    double r = (double)rand()/RAND_MAX;
+    double baseval = counter-LFU_INIT_VAL;
+    if (baseval < 0) baseval = 0;
+    double limit = 1.0/(baseval*10+1);
+    if (r < limit) counter++;
+    return counter;
+}
+
+/* Simulate an access to an entry. */
+void access_entry(struct entry *e) {
+    e->counter = log_incr(e->counter);
+    e->hits++;
+}
+
+/* Return the entry LFU value and as a side effect decrement the
+ * entry value if the decrement time was reached. */
+uint8_t scan_entry(struct entry *e) {
+    if (minutes_diff(to_16bit_minutes(time(NULL)),e->decrtime)
+        >= decr_every)
+    {
+        if (e->counter) {
+            if (e->counter > LFU_INIT_VAL*2) {
+                e->counter /= 2;
+            } else {
+                e->counter--;
+            }
+        }
+        e->decrtime = to_16bit_minutes(time(NULL));
+    }
+    return e->counter;
+}
+
+/* Print the entry info. */
+void show_entry(long pos, struct entry *e) {
+    char *tag = "normal       ";
+
+    if (pos >= 10 && pos <= 14) tag = "new no access";
+    if (pos >= 15 && pos <= 19) tag = "new accessed ";
+    if (pos >= keyspace_size -5) tag= "old no access";
+
+    printf("%ld] <%s> frequency:%d decrtime:%d [%lu hits | age:%ld sec]\n",
+        pos, tag, e->counter, e->decrtime, (unsigned long)e->hits,
+            time(NULL) - e->ctime);
+}
+
+int main(void) {
+    time_t start = time(NULL);
+    time_t new_entry_time = start;
+    time_t display_time = start;
+    struct entry *entries = malloc(sizeof(*entries)*keyspace_size);
+    long j;
+
+    /* Initialize. */
+    for (j = 0; j < keyspace_size; j++) {
+        entries[j].counter = LFU_INIT_VAL;
+        entries[j].decrtime = to_16bit_minutes(start);
+        entries[j].hits = 0;
+        entries[j].ctime = time(NULL);
+    }
+
+    while(1) {
+        time_t now = time(NULL);
+        long idx;
+
+        /* Scan N random entries (simulates the eviction under maxmemory). */
+        for (j = 0; j < 3; j++) {
+            scan_entry(entries+(rand()%keyspace_size));
+        }
+
+        /* Access a random entry: use a power-law access pattern up to
+         * 'switch_after' seconds. Then revert to flat access pattern. */
+        if (now-start < switch_after) {
+            /* Power law. */
+            idx = 1;
+            while((rand() % 21) != 0 && idx < keyspace_size) idx *= 2;
+            if (idx > keyspace_size) idx = keyspace_size;
+            idx = rand() % idx;
+        } else {
+            /* Flat. */
+            idx = rand() % keyspace_size;
+        }
+
+        /* Never access entries between position 10 and 14, so that
+         * we simulate what happens to new entries that are never
+         * accessed VS new entries which are accessed in positions
+         * 15-19.
+         *
+         * Also never access last 5 entry, so that we have keys which
+         * are never recreated (old), and never accessed. */
+        if ((idx < 10 || idx > 14) && (idx < keyspace_size-5))
+            access_entry(entries+idx);
+
+        /* Simulate the addition of new entries at positions between
+         * 10 and 19, a random one every 10 seconds. */
+        if (new_entry_time <= now) {
+            idx = 10+(rand()%10);
+            entries[idx].counter = LFU_INIT_VAL;
+            entries[idx].decrtime = to_16bit_minutes(time(NULL));
+            entries[idx].hits = 0;
+            entries[idx].ctime = time(NULL);
+            new_entry_time = now+10;
+        }
+
+        /* Show the first 20 entries and the last 20 entries. */
+        if (display_time != now) {
+            printf("=============================\n");
+            printf("Current minutes time: %d\n", (int)to_16bit_minutes(now));
+            printf("Access method: %s\n",
+                (now-start < switch_after) ? "power-law" : "flat");
+
+            for (j = 0; j < 20; j++)
+                show_entry(j,entries+j);
+
+            for (j = keyspace_size-20; j < keyspace_size; j++)
+                show_entry(j,entries+j);
+            display_time = now;
+        }
+    }
+    return 0;
+}
+
diff --git a/utils/lru/test-lru.rb b/utils/lru/test-lru.rb
new file mode 100644
index 0000000..d511e20
--- /dev/null
+++ b/utils/lru/test-lru.rb
@@ -0,0 +1,223 @@
+require 'rubygems'
+require 'redis'
+
+$runs = []; # Remember the error rate of each run for average purposes.
+$o = {};    # Options set parsing arguments
+
+def testit(filename)
+    r = Redis.new
+    r.config("SET","maxmemory","2000000")
+    if $o[:ttl]
+        r.config("SET","maxmemory-policy","volatile-ttl")
+    else
+        r.config("SET","maxmemory-policy","allkeys-lru")
+    end
+    r.config("SET","maxmemory-samples",5)
+    r.config("RESETSTAT")
+    r.flushall
+
+    html = ""
+    html << <<EOF
+    <html>
+    <body>
+    <style>
+    .box {
+        width:5px;
+        height:5px;
+        float:left;
+        margin: 1px;
+    }
+
+    .old {
+        border: 1px black solid;
+    }
+
+    .new {
+        border: 1px green solid;
+    }
+
+    .otherdb {
+        border: 1px red solid;
+    }
+
+    .ex {
+        background-color: #666;
+    }
+    </style>
+    <pre>
+EOF
+
+    # Fill the DB up to the first eviction.
+    oldsize = r.dbsize
+    id = 0
+    while true
+        id += 1
+        begin
+            r.set(id,"foo")
+        rescue
+            break
+        end
+        newsize = r.dbsize
+        break if newsize == oldsize # A key was evicted? Stop.
+        oldsize = newsize
+    end
+
+    inserted = r.dbsize
+    first_set_max_id = id
+    html << "#{r.dbsize} keys inserted.\n"
+
+    # Access keys sequentially, so that in theory the first part will be expired
+    # and the latter part will not, according to perfect LRU.
+
+    if $o[:ttl]
+        STDERR.puts "Set increasing expire value"
+        (1..first_set_max_id).each{|id|
+            r.expire(id,1000+id)
+            STDERR.print(".") if (id % 150) == 0
+        }
+    else
+        STDERR.puts "Access keys sequentially"
+        (1..first_set_max_id).each{|id|
+            r.get(id)
+            sleep 0.001
+            STDERR.print(".") if (id % 150) == 0
+        }
+    end
+    STDERR.puts
+
+    # Insert more 50% keys. We expect that the new keys will rarely be expired
+    # since their last access time is recent compared to the others.
+    #
+    # Note that we insert the first 100 keys of the new set into DB1 instead
+    # of DB0, so that we can try how cross-DB eviction works.
+    half = inserted/2
+    html << "Insert enough keys to evict half the keys we inserted.\n"
+    add = 0
+
+    otherdb_start_idx = id+1
+    otherdb_end_idx = id+100
+    while true
+        add += 1
+        id += 1
+        if id >= otherdb_start_idx && id <= otherdb_end_idx
+            r.select(1)
+            r.set(id,"foo")
+            r.select(0)
+        else
+            r.set(id,"foo")
+        end
+        break if r.info['evicted_keys'].to_i >= half
+    end
+
+    html << "#{add} additional keys added.\n"
+    html << "#{r.dbsize} keys in DB.\n"
+
+    # Check if evicted keys respect LRU
+    # We consider errors from 1 to N progressively more serious as they violate
+    # more the access pattern.
+
+    errors = 0
+    e = 1
+    error_per_key = 100000.0/first_set_max_id
+    half_set_size = first_set_max_id/2
+    maxerr = 0
+    (1..(first_set_max_id/2)).each{|id|
+        if id >= otherdb_start_idx && id <= otherdb_end_idx
+            r.select(1)
+            exists = r.exists(id)
+            r.select(0)
+        else
+            exists = r.exists(id)
+        end
+        if id < first_set_max_id/2
+            thiserr = error_per_key * ((half_set_size-id).to_f/half_set_size)
+            maxerr += thiserr
+            errors += thiserr if exists
+        elsif id >= first_set_max_id/2
+            thiserr = error_per_key * ((id-half_set_size).to_f/half_set_size)
+            maxerr += thiserr
+            errors += thiserr if !exists
+        end
+    }
+    errors = errors*100/maxerr
+
+    STDERR.puts "Test finished with #{errors}% error! Generating HTML on stdout."
+
+    html << "#{errors}% error!\n"
+    html << "</pre>"
+    $runs << errors
+
+    # Generate the graphical representation
+    (1..id).each{|id|
+        # Mark first set and added items in a different way.
+        c = "box"
+        if id >= otherdb_start_idx && id <= otherdb_end_idx
+            c << " otherdb"
+        elsif id <= first_set_max_id
+            c << " old"
+        else
+            c << " new"
+        end
+
+        # Add class if exists
+        if id >= otherdb_start_idx && id <= otherdb_end_idx
+            r.select(1)
+            exists = r.exists(id)
+            r.select(0)
+        else
+            exists = r.exists(id)
+        end
+
+        c << " ex" if exists
+        html << "<div title=\"#{id}\" class=\"#{c}\"></div>"
+    }
+
+    # Close HTML page
+
+    html << <<EOF
+    </body>
+    </html>
+EOF
+
+    f = File.open(filename,"w")
+    f.write(html)
+    f.close
+end
+
+def print_avg
+    avg = ($runs.reduce {|a,b| a+b}) / $runs.length
+    puts "#{$runs.length} runs, AVG is #{avg}"
+end
+
+if ARGV.length < 1
+    STDERR.puts "Usage: ruby test-lru.rb <html-output-filename> [--runs <count>] [--ttl]"
+    STDERR.puts "Options:"
+    STDERR.puts "  --runs <count>    Execute the test <count> times."
+    STDERR.puts "  --ttl             Set keys with increasing TTL values"
+    STDERR.puts "                    (starting from 1000 seconds) in order to"
+    STDERR.puts "                    test the volatile-lru policy."
+    exit 1
+end
+
+filename = ARGV[0]
+$o[:numruns] = 1
+
+# Options parsing
+i = 1
+while i < ARGV.length
+    if ARGV[i] == '--runs'
+        $o[:numruns] = ARGV[i+1].to_i
+        i+= 1
+    elsif ARGV[i] == '--ttl'
+        $o[:ttl] = true
+    else
+        STDERR.puts "Unknown option #{ARGV[i]}"
+        exit 1
+    end
+    i+= 1
+end
+
+$o[:numruns].times {
+    testit(filename)
+    print_avg if $o[:numruns] != 1
+}
diff --git a/utils/redis-copy.rb b/utils/redis-copy.rb
new file mode 100644
index 0000000..7c5c52d
--- /dev/null
+++ b/utils/redis-copy.rb
@@ -0,0 +1,35 @@
+# redis-copy.rb - Copyright (C) 2009-2010 Salvatore Sanfilippo
+# BSD license, See the COPYING file for more information.
+#
+# Copy the whole dataset from one Redis instance to another one
+#
+# WARNING: this utility is deprecated and serves as a legacy adapter
+#          for the more-robust redis-copy gem.
+
+require 'shellwords'
+
+def redisCopy(opts={})
+  src = "#{opts[:srchost]}:#{opts[:srcport]}"
+  dst = "#{opts[:dsthost]}:#{opts[:dstport]}"
+  `redis-copy #{src.shellescape} #{dst.shellescape}`
+rescue Errno::ENOENT
+  $stderr.puts 'This utility requires the redis-copy executable',
+               'from the redis-copy gem on https://rubygems.org',
+               'To install it, run `gem install redis-copy`.'
+  exit 1
+end
+
+$stderr.puts "This utility is deprecated. Use the redis-copy gem instead."
+if ARGV.length != 4
+    puts "Usage: redis-copy.rb <srchost> <srcport> <dsthost> <dstport>"
+    exit 1
+end
+puts "WARNING: it's up to you to FLUSHDB the destination host before to continue, press any key when ready."
+STDIN.gets
+srchost = ARGV[0]
+srcport = ARGV[1]
+dsthost = ARGV[2]
+dstport = ARGV[3]
+puts "Copying #{srchost}:#{srcport} into #{dsthost}:#{dstport}"
+redisCopy(:srchost => srchost, :srcport => srcport.to_i,
+          :dsthost => dsthost, :dstport => dstport.to_i)
diff --git a/utils/redis-sha1.rb b/utils/redis-sha1.rb
new file mode 100644
index 0000000..6a8b4f3
--- /dev/null
+++ b/utils/redis-sha1.rb
@@ -0,0 +1,52 @@
+# redis-sha1.rb - Copyright (C) 2009 Salvatore Sanfilippo
+# BSD license, See the COPYING file for more information.
+#
+# Performs the SHA1 sum of the whole dataset.
+# This is useful to spot bugs in persistence related code and to make sure
+# Slaves and Masters are in SYNC.
+#
+# If you hack this code make sure to sort keys and set elements as this are
+# unsorted elements. Otherwise the sum may differ with equal dataset.
+
+require 'rubygems'
+require 'redis'
+require 'digest/sha1'
+
+def redisSha1(opts={})
+    sha1=""
+    r = Redis.new(opts)
+    r.keys('*').sort.each{|k|
+        vtype = r.type?(k)
+        if vtype == "string"
+            len = 1
+            sha1 = Digest::SHA1.hexdigest(sha1+k)
+            sha1 = Digest::SHA1.hexdigest(sha1+r.get(k))
+        elsif vtype == "list"
+            len = r.llen(k)
+            if len != 0
+                sha1 = Digest::SHA1.hexdigest(sha1+k)
+                sha1 = Digest::SHA1.hexdigest(sha1+r.list_range(k,0,-1).join("\x01"))
+            end
+        elsif vtype == "set"
+            len = r.scard(k)
+            if len != 0
+                sha1 = Digest::SHA1.hexdigest(sha1+k)
+                sha1 = Digest::SHA1.hexdigest(sha1+r.set_members(k).to_a.sort.join("\x02"))
+            end
+        elsif vtype == "zset"
+            len = r.zcard(k)
+            if len != 0
+                sha1 = Digest::SHA1.hexdigest(sha1+k)
+                sha1 = Digest::SHA1.hexdigest(sha1+r.zrange(k,0,-1).join("\x01"))
+            end
+        end
+        # puts "#{k} => #{sha1}" if len != 0
+    }
+    sha1
+end
+
+host = ARGV[0] || "127.0.0.1"
+port = ARGV[1] || "6379"
+db = ARGV[2] || "0"
+puts "Performing SHA1 of Redis server #{host} #{port} DB: #{db}"
+p "Dataset SHA1: #{redisSha1(:host => host, :port => port.to_i, :db => db)}"
diff --git a/utils/redis_init_script b/utils/redis_init_script
new file mode 100755
index 0000000..006db87
--- /dev/null
+++ b/utils/redis_init_script
@@ -0,0 +1,50 @@
+#!/bin/sh
+#
+# Simple Redis init.d script conceived to work on Linux systems
+# as it does use of the /proc filesystem.
+
+### BEGIN INIT INFO
+# Provides:     redis_6379
+# Default-Start:        2 3 4 5
+# Default-Stop:         0 1 6
+# Short-Description:    Redis data structure server
+# Description:          Redis data structure server. See https://redis.io
+### END INIT INFO
+
+REDISPORT=6379
+EXEC=/usr/local/bin/redis-server
+CLIEXEC=/usr/local/bin/redis-cli
+
+PIDFILE=/var/run/redis_${REDISPORT}.pid
+CONF="/etc/redis/${REDISPORT}.conf"
+
+case "$1" in
+    start)
+        if [ -f $PIDFILE ]
+        then
+                echo "$PIDFILE exists, process is already running or crashed"
+        else
+                echo "Starting Redis server..."
+                $EXEC $CONF
+        fi
+        ;;
+    stop)
+        if [ ! -f $PIDFILE ]
+        then
+                echo "$PIDFILE does not exist, process is not running"
+        else
+                PID=$(cat $PIDFILE)
+                echo "Stopping ..."
+                $CLIEXEC -p $REDISPORT shutdown
+                while [ -x /proc/${PID} ]
+                do
+                    echo "Waiting for Redis to shutdown ..."
+                    sleep 1
+                done
+                echo "Redis stopped"
+        fi
+        ;;
+    *)
+        echo "Please use start or stop as first argument"
+        ;;
+esac
diff --git a/utils/redis_init_script.tpl b/utils/redis_init_script.tpl
new file mode 100755
index 0000000..2e5b613
--- /dev/null
+++ b/utils/redis_init_script.tpl
@@ -0,0 +1,44 @@
+
+case "$1" in
+    start)
+        if [ -f $PIDFILE ]
+        then
+            echo "$PIDFILE exists, process is already running or crashed"
+        else
+            echo "Starting Redis server..."
+            $EXEC $CONF
+        fi
+        ;;
+    stop)
+        if [ ! -f $PIDFILE ]
+        then
+            echo "$PIDFILE does not exist, process is not running"
+        else
+            PID=$(cat $PIDFILE)
+            echo "Stopping ..."
+            $CLIEXEC -p $REDISPORT shutdown
+            while [ -x /proc/${PID} ]
+            do
+                echo "Waiting for Redis to shutdown ..."
+                sleep 1
+            done
+            echo "Redis stopped"
+        fi
+        ;;
+    status)
+        PID=$(cat $PIDFILE)
+        if [ ! -x /proc/${PID} ]
+        then
+            echo 'Redis is not running'
+        else
+            echo "Redis is running ($PID)"
+        fi
+        ;;
+    restart)
+        $0 stop
+        $0 start
+        ;;
+    *)
+        echo "Please use start, stop, restart or status as first argument"
+        ;;
+esac
diff --git a/utils/releasetools/01_create_tarball.sh b/utils/releasetools/01_create_tarball.sh
new file mode 100755
index 0000000..366a61e
--- /dev/null
+++ b/utils/releasetools/01_create_tarball.sh
@@ -0,0 +1,14 @@
+#!/bin/sh
+if [ $# != "1" ]
+then
+    echo "Usage: ./utils/releasetools/01_create_tarball.sh <version_tag>"
+    exit 1
+fi
+
+TAG=$1
+TARNAME="redis-${TAG}.tar"
+echo "Generating /tmp/${TARNAME}"
+git archive $TAG --prefix redis-${TAG}/ > /tmp/$TARNAME || exit 1
+echo "Gizipping the archive"
+rm -f /tmp/$TARNAME.gz
+gzip -9 /tmp/$TARNAME
diff --git a/utils/releasetools/02_upload_tarball.sh b/utils/releasetools/02_upload_tarball.sh
new file mode 100755
index 0000000..ef1e777
--- /dev/null
+++ b/utils/releasetools/02_upload_tarball.sh
@@ -0,0 +1,23 @@
+#!/bin/bash
+if [ $# != "1" ]
+then
+    echo "Usage: ./utils/releasetools/02_upload_tarball.sh <version_tag>"
+    exit 1
+fi
+
+echo "Uploading..."
+scp /tmp/redis-${1}.tar.gz ubuntu@host.redis.io:/var/www/download/releases/
+echo "Updating web site... "
+echo "Please check the github action tests for the release."
+echo "Press any key if it is a stable release, or Ctrl+C to abort"
+read x
+ssh ubuntu@host.redis.io "cd /var/www/download;
+                          rm -rf redis-${1}.tar.gz;
+                          wget http://download.redis.io/releases/redis-${1}.tar.gz;
+                          tar xvzf redis-${1}.tar.gz;
+                          rm -rf redis-stable;
+                          mv redis-${1} redis-stable;
+                          tar cvzf redis-stable.tar.gz redis-stable;
+                          rm -rf redis-${1}.tar.gz;
+                          shasum -a 256 redis-stable.tar.gz > redis-stable.tar.gz.SHA256SUM;
+                          "
diff --git a/utils/releasetools/03_test_release.sh b/utils/releasetools/03_test_release.sh
new file mode 100755
index 0000000..493d0b7
--- /dev/null
+++ b/utils/releasetools/03_test_release.sh
@@ -0,0 +1,28 @@
+#!/bin/sh
+set -e
+if [ $# != "1" ]
+then
+    echo "Usage: ./utils/releasetools/03_test_release.sh <version_tag>"
+    exit 1
+fi
+
+TAG=$1
+TARNAME="redis-${TAG}.tar.gz"
+DOWNLOADURL="http://download.redis.io/releases/${TARNAME}"
+
+echo "Doing sanity test on the actual tarball"
+
+cd /tmp
+rm -rf test_release_tmp_dir
+mkdir test_release_tmp_dir
+cd test_release_tmp_dir
+rm -f $TARNAME
+rm -rf redis-${TAG}
+wget $DOWNLOADURL
+tar xvzf $TARNAME
+cd redis-${TAG}
+make
+./runtest
+./runtest-sentinel
+./runtest-cluster
+./runtest-moduleapi
diff --git a/utils/releasetools/04_release_hash.sh b/utils/releasetools/04_release_hash.sh
new file mode 100755
index 0000000..d932928
--- /dev/null
+++ b/utils/releasetools/04_release_hash.sh
@@ -0,0 +1,13 @@
+#!/bin/bash
+if [ $# != "1" ]
+then
+    echo "Usage: ./utils/releasetools/04_release_hash.sh <version_tag>"
+    exit 1
+fi
+
+SHA=$(curl -s http://download.redis.io/releases/redis-${1}.tar.gz | shasum -a 256 | cut -f 1 -d' ')
+ENTRY="hash redis-${1}.tar.gz sha256 $SHA http://download.redis.io/releases/redis-${1}.tar.gz"
+echo $ENTRY >> ../redis-hashes/README
+echo "Press any key to commit, Ctrl-C to abort)."
+read yes
+(cd ../redis-hashes; git commit -a -m "${1} hash."; git push)
diff --git a/utils/releasetools/changelog.tcl b/utils/releasetools/changelog.tcl
new file mode 100755
index 0000000..2288794
--- /dev/null
+++ b/utils/releasetools/changelog.tcl
@@ -0,0 +1,35 @@
+#!/usr/bin/env tclsh
+
+if {[llength $::argv] != 2 && [llength $::argv] != 3} {
+    puts "Usage: $::argv0 <branch> <version> \[<num-commits>\]"
+    exit 1
+}
+
+set branch [lindex $::argv 0]
+set ver [lindex $::argv 1]
+if {[llength $::argv] == 3} {
+    set count [lindex ::$argv 2]
+} else {
+    set count 100
+}
+
+set template {
+================================================================================
+Redis %ver%     Released %date%
+================================================================================
+
+Upgrade urgency <URGENCY>: <DESCRIPTION>
+}
+
+set template [string trim $template]
+append template "\n\n"
+set date [clock format [clock seconds]]
+set template [string map [list %ver% $ver %date% $date] $template]
+
+append template [exec git log $branch~$count..$branch "--format=format:%an in commit %h:%n %s" --shortstat]
+
+#Older, more verbose version.
+#
+#append template [exec git log $branch~30..$branch "--format=format:+-------------------------------------------------------------------------------%n| %s%n| By %an, %ai%n+--------------------------------------------------------------------------------%nhttps://github.com/redis/redis/commit/%H%n%n%b" --stat]
+
+puts $template
diff --git a/utils/speed-regression.tcl b/utils/speed-regression.tcl
new file mode 100755
index 0000000..bf35c7d
--- /dev/null
+++ b/utils/speed-regression.tcl
@@ -0,0 +1,130 @@
+#!/usr/bin/env tclsh8.5
+# Copyright (C) 2011 Salvatore Sanfilippo
+# Released under the BSD license like Redis itself
+
+source ../tests/support/redis.tcl
+set ::port 12123
+set ::tests {PING,SET,GET,INCR,LPUSH,LPOP,SADD,SPOP,LRANGE_100,LRANGE_600,MSET}
+set ::datasize 16
+set ::requests 100000
+
+proc run-tests branches {
+    set runs {}
+    set branch_id 0
+    foreach b $branches {
+        cd ../src
+        puts "Benchmarking $b"
+        exec -ignorestderr git checkout $b 2> /dev/null
+        exec -ignorestderr make clean 2> /dev/null
+        puts "  compiling..."
+        exec -ignorestderr make 2> /dev/null
+
+        if {$branch_id == 0} {
+            puts "  copy redis-benchmark from unstable to /tmp..."
+            exec -ignorestderr cp ./redis-benchmark /tmp
+            incr branch_id
+            continue
+        }
+
+        # Start the Redis server
+        puts "  starting the server... [exec ./redis-server -v]"
+        set pids [exec echo "port $::port\nloglevel warning\n" | ./redis-server - > /dev/null 2> /dev/null &]
+        puts "  pids: $pids"
+        after 1000
+        puts "  running the benchmark"
+
+        set r [redis 127.0.0.1 $::port]
+        set i [$r info]
+        puts "  redis INFO shows version: [lindex [split $i] 0]"
+        $r close
+
+        set output [exec /tmp/redis-benchmark -n $::requests -t $::tests -d $::datasize --csv -p $::port]
+        lappend runs $b $output
+        puts "  killing server..."
+        catch {exec kill -9 [lindex $pids 0]}
+        catch {exec kill -9 [lindex $pids 1]}
+        incr branch_id
+    }
+    return $runs
+}
+
+proc get-result-with-name {output name} {
+    foreach line [split $output "\n"] {
+        lassign [split $line ","] key value
+        set key [string tolower [string range $key 1 end-1]]
+        set value [string range $value 1 end-1]
+        if {$key eq [string tolower $name]} {
+            return $value
+        }
+    }
+    return "n/a"
+}
+
+proc get-test-names output {
+    set names {}
+    foreach line [split $output "\n"] {
+        lassign [split $line ","] key value
+        set key [string tolower [string range $key 1 end-1]]
+        lappend names $key
+    }
+    return $names
+}
+
+proc combine-results {results} {
+    set tests [get-test-names [lindex $results 1]]
+    foreach test $tests {
+        puts $test
+        foreach {branch output} $results {
+            puts [format "%-20s %s" \
+                $branch [get-result-with-name $output $test]]
+        }
+        puts {}
+    }
+}
+
+proc main {} {
+    # Note: the first branch is only used in order to get the redis-benchmark
+    # executable. Tests are performed starting from the second branch.
+    set branches {
+        slowset 2.2.0 2.4.0 unstable slowset
+    }
+    set results [run-tests $branches]
+    puts "\n"
+    puts "# Test results: datasize=$::datasize requests=$::requests"
+    puts [combine-results $results]
+}
+
+# Force the user to run the script from the 'utils' directory.
+if {![file exists speed-regression.tcl]} {
+    puts "Please make sure to run speed-regression.tcl while inside /utils."
+    puts "Example: cd utils; ./speed-regression.tcl"
+    exit 1
+}
+
+# Make sure there is not already a server running on port 12123
+set is_not_running [catch {set r [redis 127.0.0.1 $::port]}]
+if {!$is_not_running} {
+    puts "Sorry, you have a running server on port $::port"
+    exit 1
+}
+
+# parse arguments
+for {set j 0} {$j < [llength $argv]} {incr j} {
+    set opt [lindex $argv $j]
+    set arg [lindex $argv [expr $j+1]]
+    if {$opt eq {--tests}} {
+        set ::tests $arg
+        incr j
+    } elseif {$opt eq {--datasize}} {
+        set ::datasize $arg
+        incr j
+    } elseif {$opt eq {--requests}} {
+        set ::requests $arg
+        incr j
+    } else {
+        puts "Wrong argument: $opt"
+        exit 1
+    }
+}
+
+main
diff --git a/utils/srandmember/README.md b/utils/srandmember/README.md
new file mode 100644
index 0000000..d3da1e8
--- /dev/null
+++ b/utils/srandmember/README.md
@@ -0,0 +1,14 @@
+The utilities in this directory plot the distribution of SRANDMEMBER to
+evaluate how fair it is.
+
+See http://theshfl.com/redis_sets for more information on the topic that lead
+to such investigation fix.
+
+showdist.rb -- shows the distribution of the frequency elements are returned.
+               The x axis is the number of times elements were returned, and
+               the y axis is how many elements were returned with such
+               frequency.
+
+showfreq.rb -- shows the frequency each element was returned.
+               The x axis is the element number.
+               The y axis is the times it was returned.
diff --git a/utils/srandmember/showdist.rb b/utils/srandmember/showdist.rb
new file mode 100644
index 0000000..2435857
--- /dev/null
+++ b/utils/srandmember/showdist.rb
@@ -0,0 +1,33 @@
+require 'redis'
+
+r = Redis.new
+r.select(9)
+r.del("myset");
+r.sadd("myset",(0..999).to_a)
+freq = {}
+100.times {
+    res = r.pipelined {
+        1000.times {
+            r.srandmember("myset")
+        }
+    }
+    res.each{|ele|
+        freq[ele] = 0 if freq[ele] == nil
+        freq[ele] += 1
+    }
+}
+
+# Convert into frequency distribution
+dist = {}
+freq.each{|item,count|
+    dist[count] = 0 if dist[count] == nil
+    dist[count] += 1
+}
+
+min = dist.keys.min
+max = dist.keys.max
+(min..max).each{|x|
+    count = dist[x]
+    count = 0 if count == nil
+    puts "#{x} -> #{"*"*count}"
+}
diff --git a/utils/srandmember/showfreq.rb b/utils/srandmember/showfreq.rb
new file mode 100644
index 0000000..625519c
--- /dev/null
+++ b/utils/srandmember/showfreq.rb
@@ -0,0 +1,23 @@
+require 'redis'
+
+r = Redis.new
+r.select(9)
+r.del("myset");
+r.sadd("myset",(0..999).to_a)
+freq = {}
+500.times {
+    res = r.pipelined {
+        1000.times {
+            r.srandmember("myset")
+        }
+    }
+    res.each{|ele|
+        freq[ele] = 0 if freq[ele] == nil
+        freq[ele] += 1
+    }
+}
+
+# Print the frequency each element was yield to process it with gnuplot
+freq.each{|item,count|
+    puts "#{item} #{count}"
+}
diff --git a/utils/systemd-redis_multiple_servers@.service b/utils/systemd-redis_multiple_servers@.service
new file mode 100644
index 0000000..108ccfc
--- /dev/null
+++ b/utils/systemd-redis_multiple_servers@.service
@@ -0,0 +1,37 @@
+# example systemd template service unit file for multiple redis-servers
+#
+# You can use this file as a blueprint for your actual template service unit
+# file, if you intend to run multiple independent redis-server instances in
+# parallel using systemd's "template unit files" feature. If you do, you will
+# want to choose a better basename for your service unit by renaming this file
+# when copying it.
+#
+# Please take a look at the provided "systemd-redis_server.service" example
+# service unit file, too, if you choose to use this approach at managing
+# multiple redis-server instances via systemd.
+
+[Unit]
+Description=Redis data structure server - instance %i
+Documentation=https://redis.io/documentation
+# This template unit assumes your redis-server configuration file(s)
+# to live at /etc/redis/redis_server_<INSTANCE_NAME>.conf
+AssertPathExists=/etc/redis/redis_server_%i.conf
+#Before=your_application.service another_example_application.service
+#AssertPathExists=/var/lib/redis
+
+[Service]
+ExecStart=/usr/local/bin/redis-server /etc/redis/redis_server_%i.conf
+LimitNOFILE=10032
+NoNewPrivileges=yes
+#OOMScoreAdjust=-900
+#PrivateTmp=yes
+Type=notify
+TimeoutStartSec=infinity
+TimeoutStopSec=infinity
+UMask=0077
+#User=redis
+#Group=redis
+#WorkingDirectory=/var/lib/redis
+
+[Install]
+WantedBy=multi-user.target
diff --git a/utils/systemd-redis_server.service b/utils/systemd-redis_server.service
new file mode 100644
index 0000000..cf15864
--- /dev/null
+++ b/utils/systemd-redis_server.service
@@ -0,0 +1,43 @@
+# example systemd service unit file for redis-server
+#
+# In order to use this as a template for providing a redis service in your
+# environment, _at the very least_ make sure to adapt the redis configuration
+# file you intend to use as needed (make sure to set "supervised systemd"), and
+# to set sane TimeoutStartSec and TimeoutStopSec property values in the unit's
+# "[Service]" section to fit your needs.
+#
+# Some properties, such as User= and Group=, are highly desirable for virtually
+# all deployments of redis, but cannot be provided in a manner that fits all
+# expectable environments. Some of these properties have been commented out in
+# this example service unit file, but you are highly encouraged to set them to
+# fit your needs.
+#
+# Please refer to systemd.unit(5), systemd.service(5), and systemd.exec(5) for
+# more information.
+
+[Unit]
+Description=Redis data structure server
+Documentation=https://redis.io/documentation
+#Before=your_application.service another_example_application.service
+#AssertPathExists=/var/lib/redis
+Wants=network-online.target
+After=network-online.target
+
+[Service]
+ExecStart=/usr/local/bin/redis-server --supervised systemd --daemonize no
+## Alternatively, have redis-server load a configuration file:
+#ExecStart=/usr/local/bin/redis-server /path/to/your/redis.conf
+LimitNOFILE=10032
+NoNewPrivileges=yes
+#OOMScoreAdjust=-900
+#PrivateTmp=yes
+Type=notify
+TimeoutStartSec=infinity
+TimeoutStopSec=infinity
+UMask=0077
+#User=redis
+#Group=redis
+#WorkingDirectory=/var/lib/redis
+
+[Install]
+WantedBy=multi-user.target
diff --git a/utils/tracking_collisions.c b/utils/tracking_collisions.c
new file mode 100644
index 0000000..f521111
--- /dev/null
+++ b/utils/tracking_collisions.c
@@ -0,0 +1,76 @@
+/* This is a small program used in order to understand the collision rate
+ * of CRC64 (ISO version) VS other stronger hashing functions in the context
+ * of hashing keys for the Redis "tracking" feature (client side caching
+ * assisted by the server).
+ *
+ * The program attempts to hash keys with common names in the form of
+ *
+ *  prefix:<counter>
+ *
+ * And counts the resulting collisions generated in the 24 bits of output
+ * needed for the tracking feature invalidation table (16 millions + entries)
+ *
+ * Compile with:
+ *
+ *  cc -O2 ./tracking_collisions.c ../src/crc64.c ../src/sha1.c
+ *  ./a.out
+ *
+ * --------------------------------------------------------------------------
+ *
+ * Copyright (C) 2019 Salvatore Sanfilippo
+ * This code is released under the BSD 2 clause license.
+ */
+
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdio.h>
+#include "../src/crc64.h"
+#include "../src/sha1.h"
+
+#define TABLE_SIZE (1<<24)
+int Table[TABLE_SIZE];
+
+uint64_t crc64Hash(char *key, size_t len) {
+    return crc64(0,(unsigned char*)key,len);
+}
+
+uint64_t sha1Hash(char *key, size_t len) {
+    SHA1_CTX ctx;
+    unsigned char hash[20];
+
+    SHA1Init(&ctx);
+    SHA1Update(&ctx,(unsigned char*)key,len);
+    SHA1Final(hash,&ctx);
+    uint64_t hash64;
+    memcpy(&hash64,hash,sizeof(hash64));
+    return hash64;
+}
+
+/* Test the hashing function provided as callback and return the
+ * number of collisions found. */
+unsigned long testHashingFunction(uint64_t (*hash)(char *, size_t)) {
+    unsigned long collisions = 0;
+    memset(Table,0,sizeof(Table));
+    char *prefixes[] = {"object", "message", "user", NULL};
+    for (int i = 0; prefixes[i] != NULL; i++) {
+        for (int j = 0; j < TABLE_SIZE/2; j++) {
+            char keyname[128];
+            size_t keylen = snprintf(keyname,sizeof(keyname),"%s:%d",
+                                     prefixes[i],j);
+            uint64_t bucket = hash(keyname,keylen) % TABLE_SIZE;
+            if (Table[bucket]) {
+                collisions++;
+            } else {
+                Table[bucket] = 1;
+            }
+        }
+    }
+    return collisions;
+}
+
+int main(void) {
+    printf("SHA1 : %lu\n", testHashingFunction(sha1Hash));
+    printf("CRC64: %lu\n", testHashingFunction(crc64Hash));
+    return 0;
+}
diff --git a/utils/whatisdoing.sh b/utils/whatisdoing.sh
new file mode 100755
index 0000000..68d7f7c
--- /dev/null
+++ b/utils/whatisdoing.sh
@@ -0,0 +1,24 @@
+# This script is from http://poormansprofiler.org/
+#
+# NOTE: Instead of using this script, you should use the Redis
+# Software Watchdog, which provides a similar functionality but in
+# a more reliable / easy to use way.
+#
+# Check https://redis.io/topics/latency for more information.
+
+#!/bin/bash
+nsamples=1
+sleeptime=0
+pid=$(ps auxww | grep '[r]edis-server' | awk '{print $2}')
+
+for x in $(seq 1 $nsamples)
+  do
+    gdb -ex "set pagination 0" -ex "thread apply all bt" -batch -p $pid
+    sleep $sleeptime
+  done | \
+awk '
+  BEGIN { s = ""; } 
+  /Thread/ { print s; s = ""; } 
+  /^\#/ { if (s != "" ) { s = s "," $4} else { s = $4 } } 
+  END { print s }' | \
+sort | uniq -c | sort -r -n -k 1,1