From 2cb3b1eab0a4a8560cdeddd885d987345b81e6f9 Mon Sep 17 00:00:00 2001
From: Philippe Caseiro <pcaseiro@cadoles.com>
Date: Tue, 15 May 2018 12:17:25 +0200
Subject: [PATCH] Adding support for a second instance !

Redis cluster needs 6 hosts for work ... it's a lot.
To trick him each node can be Master and slave for another node.

;)
---
 creolefuncs/redis.py      |   3 +
 dicos/90_redis.xml        | 147 ++++++-
 postservice/90-redis-init |  34 +-
 tmpl/redis-cluster.conf   |  12 +-
 tmpl/redis-slave.conf     | 834 ++++++++++++++++++++++++++++++++++++++
 5 files changed, 1007 insertions(+), 23 deletions(-)
 create mode 100644 tmpl/redis-slave.conf

diff --git a/creolefuncs/redis.py b/creolefuncs/redis.py
index 87bb432..967f764 100644
--- a/creolefuncs/redis.py
+++ b/creolefuncs/redis.py
@@ -6,3 +6,6 @@
 #
 def add(num1, num2):
     return str(int(num1) + int(num2)).decode("utf-8")
+
+def intAdd(num1, num2):
+    return int(num1) + int(num2)
diff --git a/dicos/90_redis.xml b/dicos/90_redis.xml
index c0e40da..2f74723 100644
--- a/dicos/90_redis.xml
+++ b/dicos/90_redis.xml
@@ -3,12 +3,16 @@
     <files>
         <!-- System configuration -->
         <file filelist='redis' name='/etc/redis/redis.conf' mkdir='True' rm='True'/>
+        <file filelist='redisSlave' name='/etc/redis/redis-slave.conf' mkdir='True' rm='True'/>
         <file filelist='redisCl' name='/etc/redis/cluster.conf' source='redis-cluster.conf' mkdir='True' rm='True'/>
         <service servicelist="svredis">redis-server</service>
+        <service servicelist="svredisSlave">redis2-server</service>
         <service_access service='redis-server'>
             <port service_accesslist='saRedis' protocol='tcp' port_type='SymLinkOption'>redisPort</port>
             <port service_accesslist='saRedis' protocol='tcp' port_type='SymLinkOption'>redisClPort</port>
-			<tcpwrapper>redis-server</tcpwrapper>
+            <port service_accesslist='saRedisSlave' protocol='tcp' port_type='SymLinkOption'>redisPortSlave</port>
+            <port service_accesslist='saRedisSlave' protocol='tcp' port_type='SymLinkOption'>redisClPortSlave</port>
+            <tcpwrapper>redis-server</tcpwrapper>
         </service_access>
         <service_restriction service='redis-server'>
                <ip interface='auto' netmask='rdClmask' netmask_type='SymLinkOption' ip_type='SymLinkOption'>rdClIP</ip>
@@ -24,10 +28,15 @@
             <variable name='redisMode' type='string' description="Mode d'utilisation de Redis">
                 <value>Local</value>
             </variable>
-            <variable name='redisPort' type='string' description="Port d'écoute du service Redis">
+            <variable name='redisSlaveInstance' type='oui/non' description="Voulez-vous lancer une instance esclave Redis sur ce serveur ?">
+                <value>non</value>
+            </variable>
+            <!-- Instance Principale-->
+            <variable name='redisInstanceName' type='string' description="Nom de l'instance secondaire"/>
+            <variable name='redisPort' type='number' description="Port d'écoute du service Redis">
                 <value>6379</value>
             </variable>
-            <variable name='redisClPort' type='string' description="Port d'écoute du service Cluster Redis"/>
+            <variable name='redisClPort' type='number' description="Port d'écoute du service Cluster Redis"/>
             <variable name='redisMaxMemory' type='number' description="Quantité de mémoire utilisable par Redis en Mo">
                 <value>512</value>
             </variable>
@@ -37,6 +46,23 @@
             <variable name='redisTCPKeepAlive' type='number' description="Intervalle entre le dernier envoi de paquet TCP et la réponse ACK (en secondes)">
                 <value>60</value>
             </variable>
+            <!-- Instance Secondaire -->
+            <variable name='redisSlaveInstanceName' type='string' description="Nom de l'instance secondaire"/>
+            <variable name='redisSlaveInstanceMaster' type='string' description="Nom du noeud a répliquer sur l'instance secondaire"/>
+            <variable name='redisPortSlave' type='number' description="Port d'écoute du service Redis">
+                <value>6379</value>
+            </variable>
+            <variable name='redisClPortSlave' type='number' description="Port d'écoute du service Cluster Redis"/>
+            <variable name='redisMaxMemorySlave' type='number' description="Quantité de mémoire utilisable par Redis en Mo">
+                <value>512</value>
+            </variable>
+            <variable name='redisMemoryPolicySlave' type='string' description='Méthode de libération de mémoire lorsque la maximum est atteint '>
+                <value>noeviction</value>
+            </variable>
+            <variable name='redisTCPKeepAliveSlave' type='number' description="Intervalle entre le dernier envoi de paquet TCP et la réponse ACK (en secondes)">
+                <value>60</value>
+            </variable>
+            <!-- Autorisations d'accès -->
             <variable name='rdClIP' type='ip' description="Adresse IP réseau autorisée a utiliser le service Redis" multi='True'/>
             <variable name='rdClmask' type='ip' description="Masque de sous réseau"/>
 
@@ -46,11 +72,23 @@
             </variable>
             <variable name='rdClMember' type='string' description="Nom du noeud" multi='True'/>
             <variable name='rdClMemberIP' type='ip' description="Adresse IP du noeud" multi='True'/>
-            <variable name='rdClMemberPort' type='number' description="Port d'écoute du noeud" multi='True'/>
+            <variable name='rdClMemberPort' type='number' description="Port d'écoute du noeud" multi='True'>
+                <value>6379</value>
+            </variable>
             <variable name='rdClMemberRole' type='ip' description="Rôle du membre"/>
-            <variable name='rdClMemberMaster' type='string' description="Noeud source des données pour ce membre"/>
+            <variable name='rdClMemberMaster' type='string' description="Nom du neoud a répliquer sur ce membre"/>
+            <variable name='rdClMemberAsSlave' type='oui/non' description="Ce noeud dispose de 2 instances ?">
+                <value>non</value>
+            </variable>
+            <variable name='rdClMemberSlaveName' type='string' description="Nom de l'instance secondaire"/>
+            <variable name='rdClMemberSlaveIP' type='ip' description="IP de l'instance secondaire"/>
+            <variable name='rdClMemberSlavePort' type='number' description="Port de l'instance secondaire"/>
+            <variable name='rdClMemberSlaveRole' type='string' description="Rôle de l'instance secondaire" hidden='True'/>
+            <variable name='rdClMemberSlaveMaster' type='string' description="Noeud du noeud répliquer sur cette instance secondaire"/>
         </family>
         <separators>
+            <separator name='redisInstanceName'>Instance Principale</separator>
+            <separator name='redisSlaveInstanceName'>Instance Secondaire</separator>
             <separator name='rdClIP'>Autorisation d'accès au service Redis</separator>
             <separator name='redisRole'>Grappe Redis</separator>
             <separator name='rdClMemberIP'>Serveurs membres de la grappe Redis</separator>
@@ -61,24 +99,56 @@
             <param>non</param>
             <target type='filelist'>redis</target>
             <target type='family'>Redis</target>
-            <target type='service_accesslist'>saredis</target>
+            <target type='service_accesslist'>saRedis</target>
+            <target type='service_accesslist'>saRedisSlave</target>
             <target type='servicelist'>svredis</target>
         </condition>
 
+        <condition name='disabled_if_in' source='redisSlaveInstance'>
+            <param>non</param>
+            <target type='filelist'>redisSlave</target>
+            <target type='servicelist'>svredisSlave</target>
+            <target type='service_accesslist'>saRedisSlave</target>
+            <target type='variable'>redisSlaveInstanceName</target>
+            <target type='variable'>redisSlaveInstanceMaster</target>
+            <target type='variable'>redisPortSlave</target>
+            <target type='variable'>redisClPortSlave</target>
+            <target type='variable'>redisMemoryPolicySlave</target>
+            <target type='variable'>redisTCPKeepAliveSlave</target>
+            <target type='variable'>redisMaxMemorySlave</target>
+        </condition>
+
+        <condition name='disabled_if_in' source='rdClMemberAsSlave'>
+            <param>non</param>
+            <target type='variable'>rdClMemberSlaveName</target>
+            <target type='variable'>rdClMemberSlaveIP</target>
+            <target type='variable'>rdClMemberSlavePort</target>
+            <target type='variable'>rdClMemberSlaveRole</target>
+            <target type='variable'>rdClMemberSlaveMaster</target>
+        </condition>
+
         <condition name='disabled_if_in' source='redisMode'>
             <param>Local</param>
             <target type='variable'>redisRole</target>
+            <target type='variable'>redisSlaveInstance</target>
             <target type='filelist'>redisCl</target>
+            <target type='variable'>redisClPort</target>
         </condition>
 
         <condition name='disabled_if_in' source='redisRole'>
             <param>Node</param>
             <target type='filelist'>redisCl</target>
-			<target type='variable'>rdClMember</target>
-			<target type='variable'>rdClMemberIP</target>
-			<target type='variable'>rdClMemberPort</target>
-			<target type='variable'>rdClMemberRole</target>
-			<target type='variable'>rdClMemberMaster</target>
+            <target type='variable'>rdClMember</target>
+            <target type='variable'>rdClMemberIP</target>
+            <target type='variable'>rdClMemberPort</target>
+            <target type='variable'>rdClMemberRole</target>
+            <target type='variable'>rdClMemberMaster</target>
+            <target type='variable'>rdClMemberAsSlave</target>
+            <target type='variable'>rdClMemberSlaveName</target>
+            <target type='variable'>rdClMemberSlaveIP</target>
+            <target type='variable'>rdClMemberSlavePort</target>
+            <target type='variable'>rdClMemberSlaveRole</target>
+            <target type='variable'>rdClMemberSlaveMaster</target>
         </condition>
 
         <condition name='disabled_if_in' source='rdClMemberRole'>
@@ -95,6 +165,12 @@
             <slave>rdClMemberPort</slave>
             <slave>rdClMemberRole</slave>
             <slave>rdClMemberMaster</slave>
+            <slave>rdClMemberAsSlave</slave>
+            <slave>rdClMemberSlaveName</slave>
+            <slave>rdClMemberSlaveIP</slave>
+            <slave>rdClMemberSlavePort</slave>
+            <slave>rdClMemberSlaveRole</slave>
+            <slave>rdClMemberSlaveMaster</slave>
         </group>
         <check name="valid_enum" target="redisRole">
             <param>['Leader','Node']</param>
@@ -108,10 +184,57 @@
         <check name="valid_enum" target="redisMemoryPolicy">
             <param>['noeviction', 'allkeys-lru','volatile-lru','volatile-random', 'allkeys-random','volatile-ttl']</param>
         </check>
-        <fill name='add' target='redisClPort'>
+
+        <fill name='concat' target="redisSlaveInstanceName">
+            <param type='eole' name='valeur1'>redisInstanceName</param>
+            <param name='valeur2'>Second</param>
+        </fill>
+
+        <fill name='concat' target="rdClMemberSlaveName">
+            <param type='eole' name='valeur1'>rdClMember</param>
+            <param name='valeur2'>Second</param>
+        </fill>
+
+        <fill name='calc_val' target="rdClMemberSlaveIP">
+            <param type='eole' name='valeur'>rdClMemberIP</param>
+        </fill>
+        <auto name='calc_val' target='rdClMemberSlaveRole'>
+            <param>slave</param>
+        </auto>
+
+        <fill name='intAdd' target='rdClMemberSlavePort'>
+            <param type='eole' name='num1'>rdClMemberPort</param>
+            <param name='num2'>2000</param>
+        </fill>
+
+        <fill name='calc_val' target='redisInstanceName'>
+            <param type='eole' name='valeur'>nom_machine</param>
+        </fill>
+
+        <fill name='intAdd' target='redisClPort'>
             <param type='eole' name='num1'>redisPort</param>
             <param name='num2'>10000</param>
         </fill>
+
+        <fill name='intAdd' target='redisPortSlave'>
+            <param type='eole' name='num1'>redisPort</param>
+            <param name='num2'>2000</param>
+        </fill>
+
+        <fill name='intAdd' target='redisClPortSlave'>
+            <param type='eole' name='num1'>redisPortSlave</param>
+            <param name='num2'>10000</param>
+        </fill>
+        <fill name='calc_val' target='redisMaxMemorySlave'>
+            <param type='eole' name='valeur'>redisMaxMemory</param>
+        </fill>
+        <fill name='calc_val' target='redisMemoryPolicySlave'>
+            <param type='eole' name='valeur'>redisMemoryPolicy</param>
+        </fill>
+        <fill name='calc_val' target='redisTCPKeepAliveSlave'>
+            <param type='eole' name='valeur'>redisTCPKeepAlive</param>
+        </fill>
+
     </constraints>
     <help>
         <variable name='activer_redis'>Activer le service de cache Redis</variable>
diff --git a/postservice/90-redis-init b/postservice/90-redis-init
index d65418a..704a8dd 100755
--- a/postservice/90-redis-init
+++ b/postservice/90-redis-init
@@ -52,8 +52,17 @@ function getNodeID()
     else
         searchCmd="awk '/${3}:${4}@/ { print \$1  }'"
     fi
-    redisRun $1 $2 cluster nodes | eval ${searchCmd}
-    return ${?}
+	result=$(redisRun $1 $2 cluster nodes | eval ${searchCmd})
+	rcode=${?}
+
+	if [[ -z ${result} ]]
+	then
+		searchCmd="awk '/${3}:${4}@/ { print \$1   }'"
+		result=$(redisRun $1 $2 cluster nodes | eval ${searchCmd})
+		rcode=${?}
+	fi
+	echo ${result}
+	return ${rcode}
 }
 
 function redisClusterForgetAll()
@@ -112,10 +121,13 @@ declare -A PORTS
 declare -A ROLES
 declare -A MASTERS
 declare -A NIDS
+declare LeaderIP
+declare LeaderPort
 index=0
 
 while read line
 do
+	[[ ${line} =~ ^# ]] && continue
 	line=${line//::/:none:}
 	li=(${line//:/ })
 
@@ -124,7 +136,13 @@ do
     port=${li[2]}
     role=${li[3]}
     master=${li[4]}
+	ntype=${li[5]}
 
+	if [[ ${ntype} == "Leader" ]] 
+	then
+		LeaderIP=${ip}
+		LeaderPort=${port}
+	fi
     NAMES+=(${name})
     IPADDRS+=([${name}]=${ip})
 	PORTS+=([${name}]=${port})
@@ -133,12 +151,12 @@ do
 done < ${CONF}
 
 # If the cluster is "ok" don't do anything
-st=$(redisClusterIsOK ${IPADDRS["Leader"]} ${PORTS["Leader"]})
+st=$(redisClusterIsOK ${LeaderIP} ${LeaderPort})
 #[[ ${?} -eq 0 ]] && exit 0
 
 if [[ ${1} == "forget" ]]
 then
-    redisClusterForgetAll ${IPADDRS["Leader"]} ${PORTS["Leader"]}
+    redisClusterForgetAll ${LeaderIP} ${LeaderPort}
     exit ${?}
 fi
 
@@ -160,7 +178,7 @@ for node in ${NAMES[@]}
 do
     try=3
     scmd="awk '/${IPADDRS[$node]}:${PORTS[${node}]}/ {print \$8}'"
-    while [[ $(redisRun ${IPADDRS['Leader']} ${PORTS['Leader']} "cluster nodes" | eval ${scmd}) != "connected" ]]
+    while [[ $(redisRun ${LeaderIP} ${LeaderPort} "cluster nodes" | eval ${scmd}) != "connected" ]]
     do
         sleep 1
         try=$((try-1))
@@ -196,7 +214,7 @@ echo " * Configuring replication."
 NIDS+=()
 for node in ${NAMES[@]}
 do
-   NIDS+=([${node}]=$(getNodeID ${IPADDRS["Leader"]} ${PORTS["Leader"]} ${IPADDRS[${node}]} ${PORTS[${node}]}))
+   NIDS+=([${node}]=$(getNodeID ${LeaderIP} ${LeaderPort} ${IPADDRS[${node}]} ${PORTS[${node}]}))
 done
 
 for node in ${NAMES[@]}
@@ -206,12 +224,12 @@ do
     redisAddReplica ${IPADDRS[${node}]} ${PORTS[${node}]} ${NIDS[${MASTERS[${node}]}]}
 done
 
-sleep 2
+sleep 5
 
 echo
 echo "Cluster status :"
 echo
-redisRun ${IPADDRS["Leader"]} ${PORTS["Leader"]} cluster info
+redisRun ${LeaderIP} ${LeaderPort} cluster info
 echo
 
 
diff --git a/tmpl/redis-cluster.conf b/tmpl/redis-cluster.conf
index 4c9a1a2..3dc4494 100644
--- a/tmpl/redis-cluster.conf
+++ b/tmpl/redis-cluster.conf
@@ -1,10 +1,16 @@
 %if %%getVar('activer_redis','non') == 'oui' and %%getVar('redisRole','Node') == 'Leader'
-Leader:%%adresse_ip_eth0:%%{redisPort}:master::
+%%redisInstanceName:%%adresse_ip_eth0:%%{redisPort}:master::Leader:
+   %if %%getVar('redisSlaveInstance','non') == 'oui'
+%%redisSlaveInstanceName:%%adresse_ip_eth0:%%{redisPortSlave}:slave:%%{redisSlaveInstanceMaster}:Node:
+	%end if
    %for %%node in %%getVar('rdClMember',[])
       %if %%node.rdClMemberRole == 'master'
-%%{node}:%%{node.rdClMemberIP}:%%{node.rdClMemberPort}:%%{node.rdClMemberRole}::
+%%{node}:%%{node.rdClMemberIP}:%%{node.rdClMemberPort}:%%{node.rdClMemberRole}::Node:
       %else
-%%{node}:%%{node.rdClMemberIP}:%%{node.rdClMemberPort}:%%{node.rdClMemberRole}:%%{node.rdClMemberMaster}:
+%%{node}:%%{node.rdClMemberIP}:%%{node.rdClMemberPort}:%%{node.rdClMemberRole}:%%{node.rdClMemberMaster}:Node:
+      %end if
+      %if %%node.rdClMemberAsSlave == 'oui'
+%%{node.rdClMemberSlaveName}:%%{node.rdClMemberSlaveIP}:%%{node.rdClMemberSlavePort}:%%{node.rdClMemberSlaveRole}:%%{node.rdClMemberSlaveMaster}:Node:
       %end if
    %end for
 %end if
diff --git a/tmpl/redis-slave.conf b/tmpl/redis-slave.conf
new file mode 100644
index 0000000..dde3ad4
--- /dev/null
+++ b/tmpl/redis-slave.conf
@@ -0,0 +1,834 @@
+# Redis configuration file example.
+#
+# Note that in order to read the configuration file, Redis must be
+# started with the file path as first argument:
+#
+# ./redis-server /path/to/redis.conf
+
+# Note on units: when memory size is needed, it is possible to specify
+# it in the usual form of 1k 5GB 4M and so forth:
+#
+# 1k => 1000 bytes
+# 1kb => 1024 bytes
+# 1m => 1000000 bytes
+# 1mb => 1024*1024 bytes
+# 1g => 1000000000 bytes
+# 1gb => 1024*1024*1024 bytes
+#
+# units are case insensitive so 1GB 1Gb 1gB are all the same.
+
+################################## INCLUDES ###################################
+
+# Include one or more other config files here.  This is useful if you
+# have a standard template that goes to all Redis servers but also need
+# to customize a few per-server settings.  Include files can include
+# other files, so use this wisely.
+#
+# Notice option "include" won't be rewritten by command "CONFIG REWRITE"
+# from admin or Redis Sentinel. Since Redis always uses the last processed
+# line as value of a configuration directive, you'd better put includes
+# at the beginning of this file to avoid overwriting config change at runtime.
+#
+# If instead you are interested in using includes to override configuration
+# options, it is better to use include as the last line.
+#
+# include /path/to/local.conf
+# include /path/to/other.conf
+
+################################## NETWORK #####################################
+
+# By default, if no "bind" configuration directive is specified, Redis listens
+# for connections from all the network interfaces available on the server.
+# It is possible to listen to just one or multiple selected interfaces using
+# the "bind" configuration directive, followed by one or more IP addresses.
+#
+# Examples:
+#
+# bind 192.168.1.100 10.0.0.1
+# bind 127.0.0.1 ::1
+#
+# ~~~ WARNING ~~~ If the computer running Redis is directly exposed to the
+# internet, binding to all the interfaces is dangerous and will expose the
+# instance to everybody on the internet. So by default we uncomment the
+# following bind directive, that will force Redis to listen only into
+# the IPv4 lookback interface address (this means Redis will be able to
+# accept connections only from clients running into the same computer it
+# is running).
+#
+# IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES
+# JUST COMMENT THE FOLLOWING LINE.
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+bind 0.0.0.0
+
+# Protected mode is a layer of security protection, in order to avoid that
+# Redis instances left open on the internet are accessed and exploited.
+#
+# When protected mode is on and if:
+#
+# 1) The server is not binding explicitly to a set of addresses using the
+#    "bind" directive.
+# 2) No password is configured.
+#
+# The server only accepts connections from clients connecting from the
+# IPv4 and IPv6 loopback addresses 127.0.0.1 and ::1, and from Unix domain
+# sockets.
+#
+# By default protected mode is enabled. You should disable it only if
+# you are sure you want clients from other hosts to connect to Redis
+# even if no authentication is configured, nor a specific set of interfaces
+# are explicitly listed using the "bind" directive.
+protected-mode no
+
+# Accept connections on the specified port, default is 6379 (IANA #815344).
+# If port 0 is specified Redis will not listen on a TCP socket.
+port %%redisPortSlave
+
+# TCP listen() backlog.
+#
+# In high requests-per-second environments you need an high backlog in order
+# to avoid slow clients connections issues. Note that the Linux kernel
+# will silently truncate it to the value of /proc/sys/net/core/somaxconn so
+# make sure to raise both the value of somaxconn and tcp_max_syn_backlog
+# in order to get the desired effect.
+tcp-backlog 511
+
+# Unix socket.
+#
+# Specify the path for the Unix socket that will be used to listen for
+# incoming connections. There is no default, so Redis will not listen
+# on a unix socket when not specified.
+#
+# unixsocket /var/run/redis/redis.sock
+# unixsocketperm 700
+
+# Close the connection after a client is idle for N seconds (0 to disable)
+timeout 0
+
+# TCP keepalive.
+#
+# If non-zero, use SO_KEEPALIVE to send TCP ACKs to clients in absence
+# of communication. This is useful for two reasons:
+#
+# 1) Detect dead peers.
+# 2) Take the connection alive from the point of view of network
+#    equipment in the middle.
+#
+# On Linux, the specified value (in seconds) is the period used to send ACKs.
+# Note that to close the connection the double of the time is needed.
+# On other kernels the period depends on the kernel configuration.
+#
+# A reasonable value for this option is 300 seconds, which is the new
+# Redis default starting with Redis 3.2.1.
+tcp-keepalive %%redisTCPKeepAliveSlave
+
+################################# GENERAL #####################################
+
+# By default Redis does not run as a daemon. Use 'yes' if you need it.
+# Note that Redis will write a pid file in /var/run/redis.pid when daemonized.
+daemonize yes
+
+# If you run Redis from upstart or systemd, Redis can interact with your
+# supervision tree. Options:
+#   supervised no      - no supervision interaction
+#   supervised upstart - signal upstart by putting Redis into SIGSTOP mode
+#   supervised systemd - signal systemd by writing READY=1 to $NOTIFY_SOCKET
+#   supervised auto    - detect upstart or systemd method based on
+#                        UPSTART_JOB or NOTIFY_SOCKET environment variables
+# Note: these supervision methods only signal "process is ready."
+#       They do not enable continuous liveness pings back to your supervisor.
+supervised systemd
+
+# If a pid file is specified, Redis writes it where specified at startup
+# and removes it at exit.
+#
+# When the server runs non daemonized, no pid file is created if none is
+# specified in the configuration. When the server is daemonized, the pid file
+# is used even if not specified, defaulting to "/var/run/redis.pid".
+#
+# Creating a pid file is best effort: if Redis is not able to create it
+# nothing bad happens, the server will start and run normally.
+pidfile /var/run/redis/redis-server.pid
+
+# Specify the server verbosity level.
+# This can be one of:
+# debug (a lot of information, useful for development/testing)
+# verbose (many rarely useful info, but not a mess like the debug level)
+# notice (moderately verbose, what you want in production probably)
+# warning (only very important / critical messages are logged)
+loglevel notice
+
+# Specify the log file name. Also the empty string can be used to force
+# Redis to log on the standard output. Note that if you use standard
+# output for logging but daemonize, logs will be sent to /dev/null
+logfile /var/log/redis/redis-server.log
+
+# To enable logging to the system logger, just set 'syslog-enabled' to yes,
+# and optionally update the other syslog parameters to suit your needs.
+# syslog-enabled no
+
+# Specify the syslog identity.
+# syslog-ident redis
+
+# Specify the syslog facility. Must be USER or between LOCAL0-LOCAL7.
+# syslog-facility local0
+
+# Set the number of databases. The default database is DB 0, you can select
+# a different one on a per-connection basis using SELECT <dbid> where
+# dbid is a number between 0 and 'databases'-1
+databases 16
+
+################################ SNAPSHOTTING  ################################
+#
+# Save the DB on disk:
+#
+#   save <seconds> <changes>
+#
+#   Will save the DB if both the given number of seconds and the given
+#   number of write operations against the DB occurred.
+#
+#   In the example below the behaviour will be to save:
+#   after 900 sec (15 min) if at least 1 key changed
+#   after 300 sec (5 min) if at least 10 keys changed
+#   after 60 sec if at least 10000 keys changed
+#
+#   Note: you can disable saving completely by commenting out all "save" lines.
+#
+#   It is also possible to remove all the previously configured save
+#   points by adding a save directive with a single empty string argument
+#   like in the following example:
+#
+#   save ""
+
+save 900 1
+save 300 10
+save 60 10000
+
+# By default Redis will stop accepting writes if RDB snapshots are enabled
+# (at least one save point) and the latest background save failed.
+# This will make the user aware (in a hard way) that data is not persisting
+# on disk properly, otherwise chances are that no one will notice and some
+# disaster will happen.
+#
+# If the background saving process will start working again Redis will
+# automatically allow writes again.
+#
+# However if you have setup your proper monitoring of the Redis server
+# and persistence, you may want to disable this feature so that Redis will
+# continue to work as usual even if there are problems with disk,
+# permissions, and so forth.
+stop-writes-on-bgsave-error yes
+
+# Compress string objects using LZF when dump .rdb databases?
+# For default that's set to 'yes' as it's almost always a win.
+# If you want to save some CPU in the saving child set it to 'no' but
+# the dataset will likely be bigger if you have compressible values or keys.
+rdbcompression yes
+
+# Since version 5 of RDB a CRC64 checksum is placed at the end of the file.
+# This makes the format more resistant to corruption but there is a performance
+# hit to pay (around 10%) when saving and loading RDB files, so you can disable it
+# for maximum performances.
+#
+# RDB files created with checksum disabled have a checksum of zero that will
+# tell the loading code to skip the check.
+rdbchecksum yes
+
+# The filename where to dump the DB
+dbfilename dump.rdb
+
+# The working directory.
+#
+# The DB will be written inside this directory, with the filename specified
+# above using the 'dbfilename' configuration directive.
+#
+# The Append Only File will also be created inside this directory.
+#
+# Note that you must specify a directory here, not a file name.
+dir /var/lib/redis
+
+################################## SECURITY ###################################
+
+# Require clients to issue AUTH <PASSWORD> before processing any other
+# commands.  This might be useful in environments in which you do not trust
+# others with access to the host running redis-server.
+#
+# This should stay commented out for backward compatibility and because most
+# people do not need auth (e.g. they run their own servers).
+#
+# Warning: since Redis is pretty fast an outside user can try up to
+# 150k passwords per second against a good box. This means that you should
+# use a very strong password otherwise it will be very easy to break.
+#
+#requirepass redisMasterPassword
+
+# Command renaming.
+#
+# It is possible to change the name of dangerous commands in a shared
+# environment. For instance the CONFIG command may be renamed into something
+# hard to guess so that it will still be available for internal-use tools
+# but not available for general clients.
+#
+# Example:
+#
+# rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52
+#
+# It is also possible to completely kill a command by renaming it into
+# an empty string:
+#
+# rename-command CONFIG ""
+#
+# Please note that changing the name of commands that are logged into the
+# AOF file or transmitted to slaves may cause problems.
+
+################################### LIMITS ####################################
+
+# Set the max number of connected clients at the same time. By default
+# this limit is set to 10000 clients, however if the Redis server is not
+# able to configure the process file limit to allow for the specified limit
+# the max number of allowed clients is set to the current file limit
+# minus 32 (as Redis reserves a few file descriptors for internal uses).
+#
+# Once the limit is reached Redis will close all the new connections sending
+# an error 'max number of clients reached'.
+#
+# maxclients 10000
+
+# Don't use more memory than the specified amount of bytes.
+# When the memory limit is reached Redis will try to remove keys
+# according to the eviction policy selected (see maxmemory-policy).
+#
+# If Redis can't remove keys according to the policy, or if the policy is
+# set to 'noeviction', Redis will start to reply with errors to commands
+# that would use more memory, like SET, LPUSH, and so on, and will continue
+# to reply to read-only commands like GET.
+#
+# This option is usually useful when using Redis as an LRU cache, or to set
+# a hard memory limit for an instance (using the 'noeviction' policy).
+#
+# WARNING: If you have slaves attached to an instance with maxmemory on,
+# the size of the output buffers needed to feed the slaves are subtracted
+# from the used memory count, so that network problems / resyncs will
+# not trigger a loop where keys are evicted, and in turn the output
+# buffer of slaves is full with DELs of keys evicted triggering the deletion
+# of more keys, and so forth until the database is completely emptied.
+#
+# In short... if you have slaves attached it is suggested that you set a lower
+# limit for maxmemory so that there is some free RAM on the system for slave
+# output buffers (but this is not needed if the policy is 'noeviction').
+#
+maxmemory %{redisMaxMemory}mb
+
+# MAXMEMORY POLICY: how Redis will select what to remove when maxmemory
+# is reached. You can select among five behaviors:
+#
+# volatile-lru -> remove the key with an expire set using an LRU algorithm
+# allkeys-lru -> remove any key according to the LRU algorithm
+# volatile-random -> remove a random key with an expire set
+# allkeys-random -> remove a random key, any key
+# volatile-ttl -> remove the key with the nearest expire time (minor TTL)
+# noeviction -> don't expire at all, just return an error on write operations
+#
+# Note: with any of the above policies, Redis will return an error on write
+#       operations, when there are no suitable keys for eviction.
+#
+#       At the date of writing these commands are: set setnx setex append
+#       incr decr rpush lpush rpushx lpushx linsert lset rpoplpush sadd
+#       sinter sinterstore sunion sunionstore sdiff sdiffstore zadd zincrby
+#       zunionstore zinterstore hset hsetnx hmset hincrby incrby decrby
+#       getset mset msetnx exec sort
+#
+# The default is:
+#
+maxmemory-policy %%redisMemoryPolicySlave
+
+# LRU and minimal TTL algorithms are not precise algorithms but approximated
+# algorithms (in order to save memory), so you can tune it for speed or
+# accuracy. For default Redis will check five keys and pick the one that was
+# used less recently, you can change the sample size using the following
+# configuration directive.
+#
+# The default of 5 produces good enough results. 10 Approximates very closely
+# true LRU but costs a bit more CPU. 3 is very fast but not very accurate.
+#
+# maxmemory-samples 5
+
+############################## APPEND ONLY MODE ###############################
+
+# By default Redis asynchronously dumps the dataset on disk. This mode is
+# good enough in many applications, but an issue with the Redis process or
+# a power outage may result into a few minutes of writes lost (depending on
+# the configured save points).
+#
+# The Append Only File is an alternative persistence mode that provides
+# much better durability. For instance using the default data fsync policy
+# (see later in the config file) Redis can lose just one second of writes in a
+# dramatic event like a server power outage, or a single write if something
+# wrong with the Redis process itself happens, but the operating system is
+# still running correctly.
+#
+# AOF and RDB persistence can be enabled at the same time without problems.
+# If the AOF is enabled on startup Redis will load the AOF, that is the file
+# with the better durability guarantees.
+#
+# Please check http://redis.io/topics/persistence for more information.
+
+appendonly yes
+
+# The name of the append only file (default: "appendonly.aof")
+
+appendfilename "appendonly.aof"
+
+# The fsync() call tells the Operating System to actually write data on disk
+# instead of waiting for more data in the output buffer. Some OS will really flush
+# data on disk, some other OS will just try to do it ASAP.
+#
+# Redis supports three different modes:
+#
+# no: don't fsync, just let the OS flush the data when it wants. Faster.
+# always: fsync after every write to the append only log. Slow, Safest.
+# everysec: fsync only one time every second. Compromise.
+#
+# The default is "everysec", as that's usually the right compromise between
+# speed and data safety. It's up to you to understand if you can relax this to
+# "no" that will let the operating system flush the output buffer when
+# it wants, for better performances (but if you can live with the idea of
+# some data loss consider the default persistence mode that's snapshotting),
+# or on the contrary, use "always" that's very slow but a bit safer than
+# everysec.
+#
+# More details please check the following article:
+# http://antirez.com/post/redis-persistence-demystified.html
+#
+# If unsure, use "everysec".
+
+# appendfsync always
+appendfsync everysec
+# appendfsync no
+
+# When the AOF fsync policy is set to always or everysec, and a background
+# saving process (a background save or AOF log background rewriting) is
+# performing a lot of I/O against the disk, in some Linux configurations
+# Redis may block too long on the fsync() call. Note that there is no fix for
+# this currently, as even performing fsync in a different thread will block
+# our synchronous write(2) call.
+#
+# In order to mitigate this problem it's possible to use the following option
+# that will prevent fsync() from being called in the main process while a
+# BGSAVE or BGREWRITEAOF is in progress.
+#
+# This means that while another child is saving, the durability of Redis is
+# the same as "appendfsync none". In practical terms, this means that it is
+# possible to lose up to 30 seconds of log in the worst scenario (with the
+# default Linux settings).
+#
+# If you have latency problems turn this to "yes". Otherwise leave it as
+# "no" that is the safest pick from the point of view of durability.
+
+no-appendfsync-on-rewrite no
+
+# Automatic rewrite of the append only file.
+# Redis is able to automatically rewrite the log file implicitly calling
+# BGREWRITEAOF when the AOF log size grows by the specified percentage.
+#
+# This is how it works: Redis remembers the size of the AOF file after the
+# latest rewrite (if no rewrite has happened since the restart, the size of
+# the AOF at startup is used).
+#
+# This base size is compared to the current size. If the current size is
+# bigger than the specified percentage, the rewrite is triggered. Also
+# you need to specify a minimal size for the AOF file to be rewritten, this
+# is useful to avoid rewriting the AOF file even if the percentage increase
+# is reached but it is still pretty small.
+#
+# Specify a percentage of zero in order to disable the automatic AOF
+# rewrite feature.
+
+auto-aof-rewrite-percentage 100
+auto-aof-rewrite-min-size 64mb
+
+# An AOF file may be found to be truncated at the end during the Redis
+# startup process, when the AOF data gets loaded back into memory.
+# This may happen when the system where Redis is running
+# crashes, especially when an ext4 filesystem is mounted without the
+# data=ordered option (however this can't happen when Redis itself
+# crashes or aborts but the operating system still works correctly).
+#
+# Redis can either exit with an error when this happens, or load as much
+# data as possible (the default now) and start if the AOF file is found
+# to be truncated at the end. The following option controls this behavior.
+#
+# If aof-load-truncated is set to yes, a truncated AOF file is loaded and
+# the Redis server starts emitting a log to inform the user of the event.
+# Otherwise if the option is set to no, the server aborts with an error
+# and refuses to start. When the option is set to no, the user requires
+# to fix the AOF file using the "redis-check-aof" utility before to restart
+# the server.
+#
+# Note that if the AOF file will be found to be corrupted in the middle
+# the server will still exit with an error. This option only applies when
+# Redis will try to read more data from the AOF file but not enough bytes
+# will be found.
+aof-load-truncated yes
+
+################################ LUA SCRIPTING  ###############################
+
+# Max execution time of a Lua script in milliseconds.
+#
+# If the maximum execution time is reached Redis will log that a script is
+# still in execution after the maximum allowed time and will start to
+# reply to queries with an error.
+#
+# When a long running script exceeds the maximum execution time only the
+# SCRIPT KILL and SHUTDOWN NOSAVE commands are available. The first can be
+# used to stop a script that did not yet called write commands. The second
+# is the only way to shut down the server in the case a write command was
+# already issued by the script but the user doesn't want to wait for the natural
+# termination of the script.
+#
+# Set it to 0 or a negative value for unlimited execution without warnings.
+lua-time-limit 5000
+
+################################ REDIS CLUSTER  ###############################
+#
+# ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+# WARNING EXPERIMENTAL: Redis Cluster is considered to be stable code, however
+# in order to mark it as "mature" we need to wait for a non trivial percentage
+# of users to deploy it in production.
+# ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+#
+# Normal Redis instances can't be part of a Redis Cluster; only nodes that are
+# started as cluster nodes can. In order to start a Redis instance as a
+# cluster node enable the cluster support uncommenting the following:
+#
+cluster-enabled yes
+
+# Every cluster node has a cluster configuration file. This file is not
+# intended to be edited by hand. It is created and updated by Redis nodes.
+# Every Redis Cluster node requires a different cluster configuration file.
+# Make sure that instances running in the same system do not have
+# overlapping cluster configuration file names.
+#
+cluster-config-file nodes-slave.conf
+
+# Cluster node timeout is the amount of milliseconds a node must be unreachable
+# for it to be considered in failure state.
+# Most other internal time limits are multiple of the node timeout.
+#
+cluster-node-timeout 15000
+
+# A slave of a failing master will avoid to start a failover if its data
+# looks too old.
+#
+# There is no simple way for a slave to actually have a exact measure of
+# its "data age", so the following two checks are performed:
+#
+# 1) If there are multiple slaves able to failover, they exchange messages
+#    in order to try to give an advantage to the slave with the best
+#    replication offset (more data from the master processed).
+#    Slaves will try to get their rank by offset, and apply to the start
+#    of the failover a delay proportional to their rank.
+#
+# 2) Every single slave computes the time of the last interaction with
+#    its master. This can be the last ping or command received (if the master
+#    is still in the "connected" state), or the time that elapsed since the
+#    disconnection with the master (if the replication link is currently down).
+#    If the last interaction is too old, the slave will not try to failover
+#    at all.
+#
+# The point "2" can be tuned by user. Specifically a slave will not perform
+# the failover if, since the last interaction with the master, the time
+# elapsed is greater than:
+#
+#   (node-timeout * slave-validity-factor) + repl-ping-slave-period
+#
+# So for example if node-timeout is 30 seconds, and the slave-validity-factor
+# is 10, and assuming a default repl-ping-slave-period of 10 seconds, the
+# slave will not try to failover if it was not able to talk with the master
+# for longer than 310 seconds.
+#
+# A large slave-validity-factor may allow slaves with too old data to failover
+# a master, while a too small value may prevent the cluster from being able to
+# elect a slave at all.
+#
+# For maximum availability, it is possible to set the slave-validity-factor
+# to a value of 0, which means, that slaves will always try to failover the
+# master regardless of the last time they interacted with the master.
+# (However they'll always try to apply a delay proportional to their
+# offset rank).
+#
+# Zero is the only value able to guarantee that when all the partitions heal
+# the cluster will always be able to continue.
+#
+cluster-slave-validity-factor 10
+
+# Cluster slaves are able to migrate to orphaned masters, that are masters
+# that are left without working slaves. This improves the cluster ability
+# to resist to failures as otherwise an orphaned master can't be failed over
+# in case of failure if it has no working slaves.
+#
+# Slaves migrate to orphaned masters only if there are still at least a
+# given number of other working slaves for their old master. This number
+# is the "migration barrier". A migration barrier of 1 means that a slave
+# will migrate only if there is at least 1 other working slave for its master
+# and so forth. It usually reflects the number of slaves you want for every
+# master in your cluster.
+#
+# Default is 1 (slaves migrate only if their masters remain with at least
+# one slave). To disable migration just set it to a very large value.
+# A value of 0 can be set but is useful only for debugging and dangerous
+# in production.
+#
+cluster-migration-barrier 1
+
+# By default Redis Cluster nodes stop accepting queries if they detect there
+# is at least an hash slot uncovered (no available node is serving it).
+# This way if the cluster is partially down (for example a range of hash slots
+# are no longer covered) all the cluster becomes, eventually, unavailable.
+# It automatically returns available as soon as all the slots are covered again.
+#
+# However sometimes you want the subset of the cluster which is working,
+# to continue to accept queries for the part of the key space that is still
+# covered. In order to do so, just set the cluster-require-full-coverage
+# option to no.
+#
+cluster-require-full-coverage yes
+
+# In order to setup your cluster make sure to read the documentation
+# available at http://redis.io web site.
+
+################################## SLOW LOG ###################################
+
+# The Redis Slow Log is a system to log queries that exceeded a specified
+# execution time. The execution time does not include the I/O operations
+# like talking with the client, sending the reply and so forth,
+# but just the time needed to actually execute the command (this is the only
+# stage of command execution where the thread is blocked and can not serve
+# other requests in the meantime).
+#
+# You can configure the slow log with two parameters: one tells Redis
+# what is the execution time, in microseconds, to exceed in order for the
+# command to get logged, and the other parameter is the length of the
+# slow log. When a new command is logged the oldest one is removed from the
+# queue of logged commands.
+
+# The following time is expressed in microseconds, so 1000000 is equivalent
+# to one second. Note that a negative number disables the slow log, while
+# a value of zero forces the logging of every command.
+slowlog-log-slower-than 10000
+
+# There is no limit to this length. Just be aware that it will consume memory.
+# You can reclaim memory used by the slow log with SLOWLOG RESET.
+slowlog-max-len 128
+
+################################ LATENCY MONITOR ##############################
+
+# The Redis latency monitoring subsystem samples different operations
+# at runtime in order to collect data related to possible sources of
+# latency of a Redis instance.
+#
+# Via the LATENCY command this information is available to the user that can
+# print graphs and obtain reports.
+#
+# The system only logs operations that were performed in a time equal or
+# greater than the amount of milliseconds specified via the
+# latency-monitor-threshold configuration directive. When its value is set
+# to zero, the latency monitor is turned off.
+#
+# By default latency monitoring is disabled since it is mostly not needed
+# if you don't have latency issues, and collecting data has a performance
+# impact, that while very small, can be measured under big load. Latency
+# monitoring can easily be enabled at runtime using the command
+# "CONFIG SET latency-monitor-threshold <milliseconds>" if needed.
+latency-monitor-threshold 0
+
+############################# EVENT NOTIFICATION ##############################
+
+# Redis can notify Pub/Sub clients about events happening in the key space.
+# This feature is documented at http://redis.io/topics/notifications
+#
+# For instance if keyspace events notification is enabled, and a client
+# performs a DEL operation on key "foo" stored in the Database 0, two
+# messages will be published via Pub/Sub:
+#
+# PUBLISH __keyspace@0__:foo del
+# PUBLISH __keyevent@0__:del foo
+#
+# It is possible to select the events that Redis will notify among a set
+# of classes. Every class is identified by a single character:
+#
+#  K     Keyspace events, published with __keyspace@<db>__ prefix.
+#  E     Keyevent events, published with __keyevent@<db>__ prefix.
+#  g     Generic commands (non-type specific) like DEL, EXPIRE, RENAME, ...
+#  $     String commands
+#  l     List commands
+#  s     Set commands
+#  h     Hash commands
+#  z     Sorted set commands
+#  x     Expired events (events generated every time a key expires)
+#  e     Evicted events (events generated when a key is evicted for maxmemory)
+#  A     Alias for g$lshzxe, so that the "AKE" string means all the events.
+#
+#  The "notify-keyspace-events" takes as argument a string that is composed
+#  of zero or multiple characters. The empty string means that notifications
+#  are disabled.
+#
+#  Example: to enable list and generic events, from the point of view of the
+#           event name, use:
+#
+#  notify-keyspace-events Elg
+#
+#  Example 2: to get the stream of the expired keys subscribing to channel
+#             name __keyevent@0__:expired use:
+#
+#  notify-keyspace-events Ex
+#
+#  By default all notifications are disabled because most users don't need
+#  this feature and the feature has some overhead. Note that if you don't
+#  specify at least one of K or E, no events will be delivered.
+notify-keyspace-events ""
+
+############################### ADVANCED CONFIG ###############################
+
+# Hashes are encoded using a memory efficient data structure when they have a
+# small number of entries, and the biggest entry does not exceed a given
+# threshold. These thresholds can be configured using the following directives.
+hash-max-ziplist-entries 512
+hash-max-ziplist-value 64
+
+# Lists are also encoded in a special way to save a lot of space.
+# The number of entries allowed per internal list node can be specified
+# as a fixed maximum size or a maximum number of elements.
+# For a fixed maximum size, use -5 through -1, meaning:
+# -5: max size: 64 Kb  <-- not recommended for normal workloads
+# -4: max size: 32 Kb  <-- not recommended
+# -3: max size: 16 Kb  <-- probably not recommended
+# -2: max size: 8 Kb   <-- good
+# -1: max size: 4 Kb   <-- good
+# Positive numbers mean store up to _exactly_ that number of elements
+# per list node.
+# The highest performing option is usually -2 (8 Kb size) or -1 (4 Kb size),
+# but if your use case is unique, adjust the settings as necessary.
+list-max-ziplist-size -2
+
+# Lists may also be compressed.
+# Compress depth is the number of quicklist ziplist nodes from *each* side of
+# the list to *exclude* from compression.  The head and tail of the list
+# are always uncompressed for fast push/pop operations.  Settings are:
+# 0: disable all list compression
+# 1: depth 1 means "don't start compressing until after 1 node into the list,
+#    going from either the head or tail"
+#    So: [head]->node->node->...->node->[tail]
+#    [head], [tail] will always be uncompressed; inner nodes will compress.
+# 2: [head]->[next]->node->node->...->node->[prev]->[tail]
+#    2 here means: don't compress head or head->next or tail->prev or tail,
+#    but compress all nodes between them.
+# 3: [head]->[next]->[next]->node->node->...->node->[prev]->[prev]->[tail]
+# etc.
+list-compress-depth 0
+
+# Sets have a special encoding in just one case: when a set is composed
+# of just strings that happen to be integers in radix 10 in the range
+# of 64 bit signed integers.
+# The following configuration setting sets the limit in the size of the
+# set in order to use this special memory saving encoding.
+set-max-intset-entries 512
+
+# Similarly to hashes and lists, sorted sets are also specially encoded in
+# order to save a lot of space. This encoding is only used when the length and
+# elements of a sorted set are below the following limits:
+zset-max-ziplist-entries 128
+zset-max-ziplist-value 64
+
+# HyperLogLog sparse representation bytes limit. The limit includes the
+# 16 bytes header. When an HyperLogLog using the sparse representation crosses
+# this limit, it is converted into the dense representation.
+#
+# A value greater than 16000 is totally useless, since at that point the
+# dense representation is more memory efficient.
+#
+# The suggested value is ~ 3000 in order to have the benefits of
+# the space efficient encoding without slowing down too much PFADD,
+# which is O(N) with the sparse encoding. The value can be raised to
+# ~ 10000 when CPU is not a concern, but space is, and the data set is
+# composed of many HyperLogLogs with cardinality in the 0 - 15000 range.
+hll-sparse-max-bytes 3000
+
+# Active rehashing uses 1 millisecond every 100 milliseconds of CPU time in
+# order to help rehashing the main Redis hash table (the one mapping top-level
+# keys to values). The hash table implementation Redis uses (see dict.c)
+# performs a lazy rehashing: the more operation you run into a hash table
+# that is rehashing, the more rehashing "steps" are performed, so if the
+# server is idle the rehashing is never complete and some more memory is used
+# by the hash table.
+#
+# The default is to use this millisecond 10 times every second in order to
+# actively rehash the main dictionaries, freeing memory when possible.
+#
+# If unsure:
+# use "activerehashing no" if you have hard latency requirements and it is
+# not a good thing in your environment that Redis can reply from time to time
+# to queries with 2 milliseconds delay.
+#
+# use "activerehashing yes" if you don't have such hard requirements but
+# want to free memory asap when possible.
+activerehashing yes
+
+# The client output buffer limits can be used to force disconnection of clients
+# that are not reading data from the server fast enough for some reason (a
+# common reason is that a Pub/Sub client can't consume messages as fast as the
+# publisher can produce them).
+#
+# The limit can be set differently for the three different classes of clients:
+#
+# normal -> normal clients including MONITOR clients
+# slave  -> slave clients
+# pubsub -> clients subscribed to at least one pubsub channel or pattern
+#
+# The syntax of every client-output-buffer-limit directive is the following:
+#
+# client-output-buffer-limit <class> <hard limit> <soft limit> <soft seconds>
+#
+# A client is immediately disconnected once the hard limit is reached, or if
+# the soft limit is reached and remains reached for the specified number of
+# seconds (continuously).
+# So for instance if the hard limit is 32 megabytes and the soft limit is
+# 16 megabytes / 10 seconds, the client will get disconnected immediately
+# if the size of the output buffers reach 32 megabytes, but will also get
+# disconnected if the client reaches 16 megabytes and continuously overcomes
+# the limit for 10 seconds.
+#
+# By default normal clients are not limited because they don't receive data
+# without asking (in a push way), but just after a request, so only
+# asynchronous clients may create a scenario where data is requested faster
+# than it can read.
+#
+# Instead there is a default limit for pubsub and slave clients, since
+# subscribers and slaves receive data in a push fashion.
+#
+# Both the hard or the soft limit can be disabled by setting them to zero.
+client-output-buffer-limit normal 0 0 0
+client-output-buffer-limit slave 256mb 64mb 60
+client-output-buffer-limit pubsub 32mb 8mb 60
+
+# Redis calls an internal function to perform many background tasks, like
+# closing connections of clients in timeout, purging expired keys that are
+# never requested, and so forth.
+#
+# Not all tasks are performed with the same frequency, but Redis checks for
+# tasks to perform according to the specified "hz" value.
+#
+# By default "hz" is set to 10. Raising the value will use more CPU when
+# Redis is idle, but at the same time will make Redis more responsive when
+# there are many keys expiring at the same time, and timeouts may be
+# handled with more precision.
+#
+# The range is between 1 and 500, however a value over 100 is usually not
+# a good idea. Most users should use the default of 10 and raise this up to
+# 100 only in environments where very low latency is required.
+hz 10
+
+# When a child rewrites the AOF file, if the following option is enabled
+# the file will be fsync-ed every 32 MB of data generated. This is useful
+# in order to commit the file to the disk more incrementally and avoid
+# big latency spikes.
+aof-rewrite-incremental-fsync yes