Info:

Redis server generator to create multiple Redis servers in standalone, replication (+ optional sentinel setup) and cluster enabled configurations on local listener 127.0.0.1 with starting port STARTPORT=6479 and incrementally created additional redis servers via integer passed on redis-generator.sh command line. Written for CentOS 7 only with centminmod.com LEMP stacks specifically though should work on any CentOS 7 or RHEL 7 based system.

Redis Source Install Support

• Optional redis source install support has been added. Example of using redis-generator.sh with redis 4.x source installed.

Requirements:

• Redis 6.2.0+ or higher branch is required and must be installed prior to using redis-generator.sh
• Remi YUM repository if you want to install redis server via Remi YUM repo for latest Redis 6.0 branch. centminmod.com auto installer already installs Remi YUM repo.
• Optional: stunnel for secure TLS encrypted redis remote connections.

yum list stunnel -q
Installed Packages
stunnel.x86_64      5.41-1.el7.centos      installed

rpm -qa --changelog stunnel | head -3
* Sun Jul 16 2017 George Liu <centminmod.com>
- custom stunnel 5.41 rpm built for centminmod.com

Redis Server Install:

For Centmin Mod LEMP web stacks, installing redis 6.2.x branch is simple as using these SSH command steps or using redis-install.sh script:

redis-install.sh script

./redis-install.sh install

Manual install steps provided you have installed Remi YUM repository first - which Centmin Mod LEMP stacks already have done.

yum -y install redis --enablerepo=remi --disableplugin=priorities
sed -i 's|LimitNOFILE=.*|LimitNOFILE=262144|' /etc/systemd/system/redis.service.d/limit.conf
mkdir -p /var/run/redis
chown redis:redis /var/run/redis
chmod 755 /var/run/redis
systemctl daemon-reload
systemctl start redis
systemctl enable redis
echo "vm.overcommit_memory = 1" >> /etc/sysctl.conf
echo never > /sys/kernel/mm/transparent_hugepage/enabled
echo "echo never > /sys/kernel/mm/transparent_hugepage/enabled" >> /etc/rc.local
sysctl -p

If redis isn't installed redis-generator.sh will alert you

./redis-generator.sh 

/usr/lib/systemd/system/redis.service not found
Script is for CentOS 7 only and requires redis
server installed first

Redis 6 Server Changes:

Updating from Redis 5.x to Redis 6.x may result in additional Redis servers created via redis-generator.sh not being able to start up properly - particularly on server reboot. This is due to changes with Redis 6.x and probably CentOS 7.8 systemd updates/changes. The below outlined changes will fix this startup issue for Redis 6 servers on CentOS 7.

1. Redis systemd service file's listed RuntimeDirectory=redis option seems to now actually work on CentOS 7.8 (maybe due to systemd changes/updates ?) to create the Redis runtime directory at /var/run/redis. Prior, this didn't work with Redis 5.x, so had created /etc/tmpfiles.d/redis.conf to create the runtime directory. But now that Redis 6 systemd service file's RuntimeDirectory=redis runtime option works, it will conflict with previously created /etc/tmpfiles.d/redis.conf so this file needs removal so as to not conflict and prevent the additional Redis generated instances from booting up on server reboots. redis-generator.sh has been updated with this fix for newly generated Redis server instances. But for existing Redis servers, you will need to manually remove /etc/tmpfiles.d/redis.conf.

cd  /etc/tmpfiles.d/
rm -f  /etc/tmpfiles.d/redis.conf

2. Redis systemd service files for additional Redis servers created via redis-generator.sh on Redis 6 updated servers need an additional changes in their service file as at July 2020:

Example /usr/lib/systemd/system/redis6479.service service file for Redis on port 6479 now has it's own runtime directory at /var/run/6479

change from

RuntimeDirectory=redis

change to

RuntimeDirectory=redis6479
RuntimeDirectoryMode=0755
ExecStartPost=/bin/sh -c "echo $MAINPID > /var/run/redis6479/redis_6479.pid"

and Redis 6479 port server's redis config file has daemonize no set

grep ^daemonize /etc/redis6479/redis6479.conf
daemonize no

Usage:

Default is to create the redis servers via TCP ports. You can edit UNIXSOCKET='y' variable to enable using Unix sockets instead

./redis-generator.sh

* Usage: where X equal postive integer for number of redis
servers to create with incrementing TCP redis ports
starting at STARTPORT=6479.
* prep - standalone prep command installs redis-cluster-tool
* prepupdate - standalone prep update command updates redis-cluster-tool
* multi X - no. of standalone redis instances to create
* multi-cache X - no. of standalone redis instances + disable ondisk persistence
* clusterprep X - no. of cluster enabled config instances
* clustermake 6 - to enable cluster mode + create cluster
* clustermake 9 - flag to enable cluster mode + create cluster
* replication X - create redis replication
* replication X 6579 - create replication with custom start port 6579
* replication-cache X - create redis replication + disable ondisk persistence
* replication-cache X 6579 - create replication with custom start port 6579
* delete X - no. of redis instances to delete
* delete X 6579 - no. of redis instances to delete + custom start port 6579

./redis-generator.sh prep
./redis-generator.sh prepupdate
./redis-generator.sh multi X
./redis-generator.sh multi-cache X
./redis-generator.sh clusterprep X
./redis-generator.sh clustermake 6
./redis-generator.sh clustermake 9
./redis-generator.sh replication X
./redis-generator.sh replication X 6579
./redis-generator.sh replication-cache X
./redis-generator.sh replication-cache X 6579
./redis-generator.sh delete X
./redis-generator.sh delete X 6579

For clustermake options you need to install redis-cluster-tool via prep command

./redis-generator.sh prep

When you create 2 redis servers via command:

./redis-generator.sh multi 2

You will create:

• 2 redis server starting at STARTPORT=6479 for redis on 6479 and 6480 TCP ports.
• redis systemd files for controlling each redis server at /usr/lib/systemd/system/redis6479.service and /usr/lib/systemd/system/redis6480.service
• redis pid files at /var/run/redis/redis_6479.pid and /var/run/redis/redis_6480.pid
• dedicated redis directories for each redis server instance at /etc/redis6479 and /etc/redis6480
• main /usr/bin/redis-server binary gets symlinked to dedicated redis directories at /etc/redis6479/redis-server and /etc/redis6480/redis-server
• dedicated redis config files at /etc/redis6479/redis6479.conf and /etc/redis6479/redis6480.conf
• each config file will have dbfilename as dump6479.rdb and dump6480.rdb with commented out unix sockets at /var/run/redis/redis6479.sock and /var/run/redis6480/redis6480.sock
• dedicated redis data directories at /var/lib/redis6479 and /var/lib/redis6480
• if cluster flag is used, each redis config file will reference a cluster-config-file in format of cluster-config-file nodes-150317-003235.conf where date/timestamped

If you want to create multiple redis grouped clusters, you could make a copy of redis-generator.sh as redis-generator2.sh and just edit the STARTPORT=6479 starting port variable to say STARTPORT=6579

./redis-generator.sh multi 2
./redis-generator2.sh multi 2

This would create 2x2 sets of redis servers where one set uses TCP ports 6479 and 6480 and other set uses TCP ports 6579 and 6580

ps aufxw | grep redis-server | grep -v grep
redis    20835  0.1  0.1 142896  2476 ?        Ssl  02:09   0:00 /etc/redis6479/redis-server 127.0.0.1:6479
redis    20902  0.2  0.1 142896  2476 ?        Ssl  02:09   0:00 /etc/redis6480/redis-server 127.0.0.1:6480
redis    20989  0.1  0.1 142896  2476 ?        Ssl  02:09   0:00 /etc/redis6579/redis-server 127.0.0.1:6579
redis    21056  0.1  0.1 142896  2476 ?        Ssl  02:09   0:00 /etc/redis6580/redis-server 127.0.0.1:6580

Install & Update redis-cluster-tool:

redis-cluster-tool is used to join multiple cluster enabled redis server configs created via redis-generator.sh into a redis cluster

To install redis-cluster-tool

./redis-generator.sh prep

To update redis-cluster tool

./redis-generator.sh prepupdate

Examples:

Below are various examples. For specific redis 9 node cluster setup with auto run of redis-cluster-tool example, check this example.

With DEBUG_REDISGEN='y' for dry run debug run checks

./redis-generator.sh multi 2              

Creating redis servers starting at TCP = 6479...
-------------------------------------------------------
creating redis server: redis6479.service [increment value: 0]
redis TCP port: 6479
create systemd redis6479.service
cp -a /usr/lib/systemd/system/redis.service /usr/lib/systemd/system/redis6479.service
create /etc/redis6479/redis6479.conf config file
mkdir -p /etc/redis6479
cp -a /etc/redis/redis.conf /etc/redis6479/redis6479.conf
mkdir -p /etc/systemd/system/redis6479.service.d/
\cp -af /etc/systemd/system/redis.service.d/limit.conf /etc/systemd/system/redis6479.service.d/limit.conf
sed -i "s|^port 6379|port 6479|" /etc/redis6479/redis6479.conf
mkdir -p /var/lib/redis6479
chown -R redis:redis /var/lib/redis6479
\cp -af /usr/bin/redis-server /etc/redis6479/redis-server
sed -i "s|\/usr\/bin\/redis-server|\/etc\/redis6479\/redis-server|" /usr/lib/systemd/system/redis6479.service
sed -i "s|dir \/var\/lib\/redis\/|dir \/var\/lib\/redis6479|" /etc/redis6479/redis6479.conf
sed -i 's|^daemonize no|daemonize yes|' /etc/redis6479/redis6479.conf
sed -i "s|cluster-config-file nodes-6379.conf|cluster-config-file nodes-6479.conf|" /etc/redis6479/redis6479.conf
sed -i "s|unixsocket \/tmp\/redis.sock|unixsocket \/var\/run\/redis\/redis6479.sock|" /etc/redis6479/redis6479.conf
sed -i "s|pidfile \/var\/run\/redis_6379.pid|pidfile \/var\/run\/redis\/redis_6479.pid|" /etc/redis6479/redis6479.conf
sed -i "s|\/var\/log\/redis\/redis.log|\/var\/log\/redis\/redis6479.log|" /etc/redis6479/redis6479.conf
sed -i "s|dbfilename dump.rdb|dbfilename dump6479.rdb|" /etc/redis6479/redis6479.conf
sed -i "s|appendfilename "appendonly.aof"|appendfilename "appendonly6479.aof"|" /etc/redis6479/redis6479.conf
echo "#masterauth abc123" >> /etc/redis6479/redis6479.conf
sed -i "s|\/etc\/redis.conf|\/etc\/redis6479\/redis6479.conf|" /usr/lib/systemd/system/redis6479.service
systemctl daemon-reload
systemctl restart redis6479
systemctl enable redis6479
Redis TCP 6479 Info:
redis-cli -h 127.0.0.1 -p 6479 INFO SERVER | egrep 'redis_version|redis_mode|process_id|tcp_port|uptime|executable|config_file'
-------------------------------------------------------
creating redis server: redis6480.service [increment value: 1]
redis TCP port: 6480
create systemd redis6480.service
cp -a /usr/lib/systemd/system/redis.service /usr/lib/systemd/system/redis6480.service
create /etc/redis6480/redis6480.conf config file
mkdir -p /etc/redis6480
cp -a /etc/redis/redis.conf /etc/redis6480/redis6480.conf
mkdir -p /etc/systemd/system/redis6480.service.d/
\cp -af /etc/systemd/system/redis.service.d/limit.conf /etc/systemd/system/redis6480.service.d/limit.conf
sed -i "s|^port 6379|port 6480|" /etc/redis6480/redis6480.conf
mkdir -p /var/lib/redis6480
chown -R redis:redis /var/lib/redis6480
\cp -af /usr/bin/redis-server /etc/redis6480/redis-server
sed -i "s|\/usr\/bin\/redis-server|\/etc\/redis6480\/redis-server|" /usr/lib/systemd/system/redis6480.service
sed -i "s|dir \/var\/lib\/redis\/|dir \/var\/lib\/redis6480|" /etc/redis6480/redis6480.conf
sed -i 's|^daemonize no|daemonize yes|' /etc/redis6480/redis6480.conf
sed -i "s|cluster-config-file nodes-6379.conf|cluster-config-file nodes-6480.conf|" /etc/redis6480/redis6480.conf
sed -i "s|unixsocket \/tmp\/redis.sock|unixsocket \/var\/run\/redis\/redis6480.sock|" /etc/redis6480/redis6480.conf
sed -i "s|pidfile \/var\/run\/redis_6379.pid|pidfile \/var\/run\/redis\/redis_6480.pid|" /etc/redis6480/redis6480.conf
sed -i "s|\/var\/log\/redis\/redis.log|\/var\/log\/redis\/redis6480.log|" /etc/redis6480/redis6480.conf
sed -i "s|dbfilename dump.rdb|dbfilename dump6480.rdb|" /etc/redis6480/redis6480.conf
sed -i "s|appendfilename "appendonly.aof"|appendfilename "appendonly6480.aof"|" /etc/redis6480/redis6480.conf
echo "#masterauth abc123" >> /etc/redis6480/redis6480.conf
sed -i "s|\/etc\/redis.conf|\/etc\/redis6480\/redis6480.conf|" /usr/lib/systemd/system/redis6480.service
systemctl daemon-reload
systemctl restart redis6480
systemctl enable redis6480
Redis TCP 6480 Info:
redis-cli -h 127.0.0.1 -p 6480 INFO SERVER | egrep 'redis_version|redis_mode|process_id|tcp_port|uptime|executable|config_file'

With DEBUG_REDISGEN='n' for live run and generation of redis servers with X = 1 meaning create 2x redis servers on starting port 6479 and 6480 (port incremented by 1)

./redis-generator.sh multi 2

Creating redis servers starting at TCP = 6479...
-------------------------------------------------------
creating redis server: redis6479.service [increment value: 0]
redis TCP port: 6479
create systemd redis6479.service
cp -a /usr/lib/systemd/system/redis.service /usr/lib/systemd/system/redis6479.service
create /etc/redis6479/redis6479.conf config file
mkdir -p /etc/redis6479
cp -a /etc/redis/redis.conf /etc/redis6479/redis6479.conf
-rw-r----- 1 redis root 46K Feb 13 08:07 /etc/redis6479/redis6479.conf
-rw-r--r-- 1 root  root 249 Sep 14 08:43 /usr/lib/systemd/system/redis6479.service
Created symlink from /etc/systemd/system/multi-user.target.wants/redis6479.service to /usr/lib/systemd/system/redis6479.service.
## Redis TCP 6479 Info ##
redis_version:3.2.8
redis_mode:standalone
process_id:11670
tcp_port:6479
uptime_in_seconds:0
uptime_in_days:0
executable:/etc/redis6479/redis-server
config_file:/etc/redis6479/redis6479.conf
-------------------------------------------------------
creating redis server: redis6480.service [increment value: 1]
redis TCP port: 6480
create systemd redis6480.service
cp -a /usr/lib/systemd/system/redis.service /usr/lib/systemd/system/redis6480.service
create /etc/redis6480/redis6480.conf config file
mkdir -p /etc/redis6480
cp -a /etc/redis/redis.conf /etc/redis6480/redis6480.conf
-rw-r----- 1 redis root 46K Feb 13 08:07 /etc/redis6480/redis6480.conf
-rw-r--r-- 1 root  root 249 Sep 14 08:43 /usr/lib/systemd/system/redis6480.service
Created symlink from /etc/systemd/system/multi-user.target.wants/redis6480.service to /usr/lib/systemd/system/redis6480.service.
## Redis TCP 6480 Info ##
redis_version:3.2.8
redis_mode:standalone
process_id:11738
tcp_port:6480
uptime_in_seconds:0
uptime_in_days:0
executable:/etc/redis6480/redis-server
config_file:/etc/redis6480/redis6480.conf

systemctl status redis6479
● redis6479.service - Redis persistent key-value database
   Loaded: loaded (/usr/lib/systemd/system/redis6479.service; enabled; vendor preset: disabled)
  Drop-In: /etc/systemd/system/redis6479.service.d
           └─limit.conf
   Active: active (running) since Wed 2017-03-15 17:43:50 UTC; 25s ago
 Main PID: 11670 (redis-server)
   CGroup: /system.slice/redis6479.service
           └─11670 /etc/redis6479/redis-server 127.0.0.1:6479

Mar 15 17:43:50 centos7.localdomain systemd[1]: Started Redis persistent key-value database.
Mar 15 17:43:50 centos7.localdomain systemd[1]: Starting Redis persistent key-value database...

systemctl status redis6480
● redis6480.service - Redis persistent key-value database
   Loaded: loaded (/usr/lib/systemd/system/redis6480.service; enabled; vendor preset: disabled)
  Drop-In: /etc/systemd/system/redis6480.service.d
           └─limit.conf
   Active: active (running) since Wed 2017-03-15 17:43:50 UTC; 27s ago
 Main PID: 11738 (redis-server)
   CGroup: /system.slice/redis6480.service
           └─11738 /etc/redis6480/redis-server 127.0.0.1:6480

Mar 15 17:43:50 centos7.localdomain systemd[1]: Started Redis persistent key-value database.
Mar 15 17:43:50 centos7.localdomain systemd[1]: Starting Redis persistent key-value database...

To remove created redis servers, append delete flag on end:

./redis-generator.sh delete 2

-------------------------------------------------------
Deleting redis6479.service ...
Removed symlink /etc/systemd/system/multi-user.target.wants/redis6479.service.
-------------------------------------------------------
Deleting redis6480.service ...
Removed symlink /etc/systemd/system/multi-user.target.wants/redis6480.service.
Deletion completed

Create 2 redis servers with UNIXSOCKET='y' enabled for redis Unix socket usage instead of TCP ports

./redis-generator.sh multi 2 

Creating redis servers starting at TCP = 6479...
-------------------------------------------------------
creating redis server: redis6479.service [increment value: 0]
redis TCP port: 6479
create systemd redis6479.service
cp -a /usr/lib/systemd/system/redis.service /usr/lib/systemd/system/redis6479.service
create /etc/redis6479/redis6479.conf config file
mkdir -p /etc/redis6479
cp -a /etc/redis/redis.conf /etc/redis6479/redis6479.conf
-rw-r----- 1 redis root 46K Feb 13 08:07 /etc/redis6479/redis6479.conf
-rw-r--r-- 1 root  root 249 Sep 14 08:43 /usr/lib/systemd/system/redis6479.service
Created symlink from /etc/systemd/system/multi-user.target.wants/redis6479.service to /usr/lib/systemd/system/redis6479.service.
## Redis TCP 6479 Info ##
redis_version:3.2.8
redis_mode:standalone
process_id:11919
tcp_port:0
uptime_in_seconds:0
uptime_in_days:0
executable:/etc/redis6479/redis-server
config_file:/etc/redis6479/redis6479.conf
-------------------------------------------------------
creating redis server: redis6480.service [increment value: 1]
redis TCP port: 6480
create systemd redis6480.service
cp -a /usr/lib/systemd/system/redis.service /usr/lib/systemd/system/redis6480.service
create /etc/redis6480/redis6480.conf config file
mkdir -p /etc/redis6480
cp -a /etc/redis/redis.conf /etc/redis6480/redis6480.conf
-rw-r----- 1 redis root 46K Feb 13 08:07 /etc/redis6480/redis6480.conf
-rw-r--r-- 1 root  root 249 Sep 14 08:43 /usr/lib/systemd/system/redis6480.service
Created symlink from /etc/systemd/system/multi-user.target.wants/redis6480.service to /usr/lib/systemd/system/redis6480.service.
## Redis TCP 6480 Info ##
redis_version:3.2.8
redis_mode:standalone
process_id:11990
tcp_port:0
uptime_in_seconds:0
uptime_in_days:0
executable:/etc/redis6480/redis-server
config_file:/etc/redis6480/redis6480.conf

redis server via Unix socket /var/run/redis/redis6479.sock

redis-cli -s /var/run/redis/redis6479.sock INFO SERVER
# Server
redis_version:3.2.8
redis_git_sha1:00000000
redis_git_dirty:0
redis_build_id:dd923e72e9efa6d8
redis_mode:standalone
os:Linux 3.10.0-514.10.2.el7.x86_64 x86_64
arch_bits:64
multiplexing_api:epoll
gcc_version:4.8.5
process_id:11919
run_id:2f72840fbe18342fdf57a24ff681997f9f08c26c
tcp_port:0
uptime_in_seconds:27
uptime_in_days:0
hz:10
lru_clock:13204966
executable:/etc/redis6479/redis-server
config_file:/etc/redis6479/redis6479.conf

Create 2 redis server master + slave replication on ports 6479 and 6480

./redis-generator.sh replication 2

Creating redis servers starting at TCP = 6479...
-------------------------------------------------------
creating redis server: redis6479.service [increment value: 0]
redis TCP port: 6479
create systemd redis6479.service
cp -a /usr/lib/systemd/system/redis.service /usr/lib/systemd/system/redis6479.service
create /etc/redis6479/redis6479.conf config file
mkdir -p /etc/redis6479
cp -a /etc/redis/redis.conf /etc/redis6479/redis6479.conf
-rw-r----- 1 redis root 46K Feb 13 08:07 /etc/redis6479/redis6479.conf
-rw-r--r-- 1 root  root 249 Sep 14 08:43 /usr/lib/systemd/system/redis6479.service
Created symlink from /etc/systemd/system/multi-user.target.wants/redis6479.service to /usr/lib/systemd/system/redis6479.service.
## Redis TCP 6479 Info ##
redis_version:3.2.8
redis_mode:standalone
process_id:12724
tcp_port:6479
uptime_in_seconds:0
uptime_in_days:0
executable:/etc/redis6479/redis-server
config_file:/etc/redis6479/redis6479.conf
# Replication
role:master
connected_slaves:0
master_repl_offset:0
repl_backlog_active:0
repl_backlog_size:1048576
repl_backlog_first_byte_offset:0
repl_backlog_histlen:0
-------------------------------------------------------
creating redis server: redis6480.service [increment value: 1]
redis TCP port: 6480
create systemd redis6480.service
cp -a /usr/lib/systemd/system/redis.service /usr/lib/systemd/system/redis6480.service
create /etc/redis6480/redis6480.conf config file
mkdir -p /etc/redis6480
cp -a /etc/redis/redis.conf /etc/redis6480/redis6480.conf
-rw-r----- 1 redis root 46K Feb 13 08:07 /etc/redis6480/redis6480.conf
-rw-r--r-- 1 root  root 249 Sep 14 08:43 /usr/lib/systemd/system/redis6480.service
Created symlink from /etc/systemd/system/multi-user.target.wants/redis6480.service to /usr/lib/systemd/system/redis6480.service.
## Redis TCP 6480 Info ##
redis_version:3.2.8
redis_mode:standalone
process_id:12794
tcp_port:6480
uptime_in_seconds:0
uptime_in_days:0
executable:/etc/redis6480/redis-server
config_file:/etc/redis6480/redis6480.conf
# Replication
role:slave
master_host:127.0.0.1
master_port:6479
master_link_status:up
master_last_io_seconds_ago:2
master_sync_in_progress:0
slave_repl_offset:1
slave_priority:100
slave_read_only:1
connected_slaves:0
master_repl_offset:0
repl_backlog_active:0
repl_backlog_size:1048576
repl_backlog_first_byte_offset:0
repl_backlog_histlen:0

Latest version of redis-generator.sh also supports specifying the custom STARTPORT for redis replication commands. So to create 2x redis master + slave replication starting on TCP port 6579 instead of default 6479:

./redis-generator.sh replication 2 6579

If TCP port 6579 already in use, you'll get an error

./redis-generator.sh replication 2 6579

Error: TCP port 6579 in use, try another port

Optionally, you can enable auto redis sentinel setup which is tied to the redis master instance on STARTPORT by enabling SENTINEL_SETUP='y' prior to running replication command.

• Create Redis Replication + Sentinel monitor config - 1x master + 1x slave

9 Redis server cluster

9x Redis server cluster mode with cluster flag appended for TCP ports 6479-6487 with manual run of redis-cluster-tool to join cluster. Or for specific redis 9 node cluster setup with auto run of redis-cluster-tool example, check this example.

./redis-generator.sh clusterprep 9

Creating redis servers starting at TCP = 6479...
-------------------------------------------------------
creating redis server: redis6479.service [increment value: 0]
redis TCP port: 6479
create systemd redis6479.service
cp -a /usr/lib/systemd/system/redis.service /usr/lib/systemd/system/redis6479.service
create /etc/redis6479/redis6479.conf config file
mkdir -p /etc/redis6479
cp -a /etc/redis/redis.conf /etc/redis6479/redis6479.conf
-rw-r----- 1 redis root 46K Feb 13 08:07 /etc/redis6479/redis6479.conf
-rw-r--r-- 1 root  root 249 Sep 14 08:43 /usr/lib/systemd/system/redis6479.service
enabled cluster mode with cluster-config-file nodes-150317-175739.conf
Created symlink from /etc/systemd/system/multi-user.target.wants/redis6479.service to /usr/lib/systemd/system/redis6479.service.
## Redis TCP 6479 Info ##
redis_version:3.2.8
redis_mode:cluster
process_id:12972
tcp_port:6479
uptime_in_seconds:0
uptime_in_days:0
executable:/etc/redis6479/redis-server
config_file:/etc/redis6479/redis6479.conf
# Cluster
cluster_enabled:1
-------------------------------------------------------
creating redis server: redis6480.service [increment value: 1]
redis TCP port: 6480
create systemd redis6480.service
cp -a /usr/lib/systemd/system/redis.service /usr/lib/systemd/system/redis6480.service
create /etc/redis6480/redis6480.conf config file
mkdir -p /etc/redis6480
cp -a /etc/redis/redis.conf /etc/redis6480/redis6480.conf
-rw-r----- 1 redis root 46K Feb 13 08:07 /etc/redis6480/redis6480.conf
-rw-r--r-- 1 root  root 249 Sep 14 08:43 /usr/lib/systemd/system/redis6480.service
enabled cluster mode with cluster-config-file nodes-150317-175739.conf
Created symlink from /etc/systemd/system/multi-user.target.wants/redis6480.service to /usr/lib/systemd/system/redis6480.service.
## Redis TCP 6480 Info ##
redis_version:3.2.8
redis_mode:cluster
process_id:13047
tcp_port:6480
uptime_in_seconds:0
uptime_in_days:0
executable:/etc/redis6480/redis-server
config_file:/etc/redis6480/redis6480.conf
# Cluster
cluster_enabled:1
-------------------------------------------------------
creating redis server: redis6481.service [increment value: 2]
redis TCP port: 6481
create systemd redis6481.service
cp -a /usr/lib/systemd/system/redis.service /usr/lib/systemd/system/redis6481.service
create /etc/redis6481/redis6481.conf config file
mkdir -p /etc/redis6481
cp -a /etc/redis/redis.conf /etc/redis6481/redis6481.conf
-rw-r----- 1 redis root 46K Feb 13 08:07 /etc/redis6481/redis6481.conf
-rw-r--r-- 1 root  root 249 Sep 14 08:43 /usr/lib/systemd/system/redis6481.service
enabled cluster mode with cluster-config-file nodes-150317-175739.conf
Created symlink from /etc/systemd/system/multi-user.target.wants/redis6481.service to /usr/lib/systemd/system/redis6481.service.
## Redis TCP 6481 Info ##
redis_version:3.2.8
redis_mode:cluster
process_id:13122
tcp_port:6481
uptime_in_seconds:0
uptime_in_days:0
executable:/etc/redis6481/redis-server
config_file:/etc/redis6481/redis6481.conf
# Cluster
cluster_enabled:1
-------------------------------------------------------
creating redis server: redis6482.service [increment value: 3]
redis TCP port: 6482
create systemd redis6482.service
cp -a /usr/lib/systemd/system/redis.service /usr/lib/systemd/system/redis6482.service
create /etc/redis6482/redis6482.conf config file
mkdir -p /etc/redis6482
cp -a /etc/redis/redis.conf /etc/redis6482/redis6482.conf
-rw-r----- 1 redis root 46K Feb 13 08:07 /etc/redis6482/redis6482.conf
-rw-r--r-- 1 root  root 249 Sep 14 08:43 /usr/lib/systemd/system/redis6482.service
enabled cluster mode with cluster-config-file nodes-150317-175739.conf
Created symlink from /etc/systemd/system/multi-user.target.wants/redis6482.service to /usr/lib/systemd/system/redis6482.service.
## Redis TCP 6482 Info ##
redis_version:3.2.8
redis_mode:cluster
process_id:13197
tcp_port:6482
uptime_in_seconds:0
uptime_in_days:0
executable:/etc/redis6482/redis-server
config_file:/etc/redis6482/redis6482.conf
# Cluster
cluster_enabled:1
-------------------------------------------------------
creating redis server: redis6483.service [increment value: 4]
redis TCP port: 6483
create systemd redis6483.service
cp -a /usr/lib/systemd/system/redis.service /usr/lib/systemd/system/redis6483.service
create /etc/redis6483/redis6483.conf config file
mkdir -p /etc/redis6483
cp -a /etc/redis/redis.conf /etc/redis6483/redis6483.conf
-rw-r----- 1 redis root 46K Feb 13 08:07 /etc/redis6483/redis6483.conf
-rw-r--r-- 1 root  root 249 Sep 14 08:43 /usr/lib/systemd/system/redis6483.service
enabled cluster mode with cluster-config-file nodes-150317-175739.conf
Created symlink from /etc/systemd/system/multi-user.target.wants/redis6483.service to /usr/lib/systemd/system/redis6483.service.
## Redis TCP 6483 Info ##
redis_version:3.2.8
redis_mode:cluster
process_id:13272
tcp_port:6483
uptime_in_seconds:0
uptime_in_days:0
executable:/etc/redis6483/redis-server
config_file:/etc/redis6483/redis6483.conf
# Cluster
cluster_enabled:1
-------------------------------------------------------
creating redis server: redis6484.service [increment value: 5]
redis TCP port: 6484
create systemd redis6484.service
cp -a /usr/lib/systemd/system/redis.service /usr/lib/systemd/system/redis6484.service
create /etc/redis6484/redis6484.conf config file
mkdir -p /etc/redis6484
cp -a /etc/redis/redis.conf /etc/redis6484/redis6484.conf
-rw-r----- 1 redis root 46K Feb 13 08:07 /etc/redis6484/redis6484.conf
-rw-r--r-- 1 root  root 249 Sep 14 08:43 /usr/lib/systemd/system/redis6484.service
enabled cluster mode with cluster-config-file nodes-150317-175739.conf
Created symlink from /etc/systemd/system/multi-user.target.wants/redis6484.service to /usr/lib/systemd/system/redis6484.service.
## Redis TCP 6484 Info ##
redis_version:3.2.8
redis_mode:cluster
process_id:13347
tcp_port:6484
uptime_in_seconds:0
uptime_in_days:0
executable:/etc/redis6484/redis-server
config_file:/etc/redis6484/redis6484.conf
# Cluster
cluster_enabled:1
-------------------------------------------------------
creating redis server: redis6485.service [increment value: 6]
redis TCP port: 6485
create systemd redis6485.service
cp -a /usr/lib/systemd/system/redis.service /usr/lib/systemd/system/redis6485.service
create /etc/redis6485/redis6485.conf config file
mkdir -p /etc/redis6485
cp -a /etc/redis/redis.conf /etc/redis6485/redis6485.conf
-rw-r----- 1 redis root 46K Feb 13 08:07 /etc/redis6485/redis6485.conf
-rw-r--r-- 1 root  root 249 Sep 14 08:43 /usr/lib/systemd/system/redis6485.service
enabled cluster mode with cluster-config-file nodes-150317-175739.conf
Created symlink from /etc/systemd/system/multi-user.target.wants/redis6485.service to /usr/lib/systemd/system/redis6485.service.
## Redis TCP 6485 Info ##
redis_version:3.2.8
redis_mode:cluster
process_id:13422
tcp_port:6485
uptime_in_seconds:0
uptime_in_days:0
executable:/etc/redis6485/redis-server
config_file:/etc/redis6485/redis6485.conf
# Cluster
cluster_enabled:1
-------------------------------------------------------
creating redis server: redis6486.service [increment value: 7]
redis TCP port: 6486
create systemd redis6486.service
cp -a /usr/lib/systemd/system/redis.service /usr/lib/systemd/system/redis6486.service
create /etc/redis6486/redis6486.conf config file
mkdir -p /etc/redis6486
cp -a /etc/redis/redis.conf /etc/redis6486/redis6486.conf
-rw-r----- 1 redis root 46K Feb 13 08:07 /etc/redis6486/redis6486.conf
-rw-r--r-- 1 root  root 249 Sep 14 08:43 /usr/lib/systemd/system/redis6486.service
enabled cluster mode with cluster-config-file nodes-150317-175739.conf
Created symlink from /etc/systemd/system/multi-user.target.wants/redis6486.service to /usr/lib/systemd/system/redis6486.service.
## Redis TCP 6486 Info ##
redis_version:3.2.8
redis_mode:cluster
process_id:13497
tcp_port:6486
uptime_in_seconds:0
uptime_in_days:0
executable:/etc/redis6486/redis-server
config_file:/etc/redis6486/redis6486.conf
# Cluster
cluster_enabled:1
-------------------------------------------------------
creating redis server: redis6487.service [increment value: 8]
redis TCP port: 6487
create systemd redis6487.service
cp -a /usr/lib/systemd/system/redis.service /usr/lib/systemd/system/redis6487.service
create /etc/redis6487/redis6487.conf config file
mkdir -p /etc/redis6487
cp -a /etc/redis/redis.conf /etc/redis6487/redis6487.conf
-rw-r----- 1 redis root 46K Feb 13 08:07 /etc/redis6487/redis6487.conf
-rw-r--r-- 1 root  root 249 Sep 14 08:43 /usr/lib/systemd/system/redis6487.service
enabled cluster mode with cluster-config-file nodes-150317-175739.conf
Created symlink from /etc/systemd/system/multi-user.target.wants/redis6487.service to /usr/lib/systemd/system/redis6487.service.
## Redis TCP 6487 Info ##
redis_version:3.2.8
redis_mode:cluster
process_id:13572
tcp_port:6487
uptime_in_seconds:0
uptime_in_days:0
executable:/etc/redis6487/redis-server
config_file:/etc/redis6487/redis6487.conf
# Cluster
cluster_enabled:1

Using redis-cluster-tool to then create redis cluster from the 9x redis servers created

redis-cluster-tool -C "cluster_create 127.0.0.1:6479[127.0.0.1:6480|127.0.0.1:6481] 127.0.0.1:6482[127.0.0.1:6483|127.0.0.1:6484] 127.0.0.1:6485[127.0.0.1:6486|127.0.0.1:6487]"

output

redis-cluster-tool -C "cluster_create 127.0.0.1:6479[127.0.0.1:6480|127.0.0.1:6481] 127.0.0.1:6482[127.0.0.1:6483|127.0.0.1:6484] 127.0.0.1:6485[127.0.0.1:6486|127.0.0.1:6487]"
Waiting for the nodes to join...
All nodes joined!
Cluster created success!

Get cluster state

redis-cluster-tool -a 127.0.0.1:6479 -C cluster_state -r master
master[127.0.0.1:6479] cluster_state: ok
master[127.0.0.1:6482] cluster_state: ok
master[127.0.0.1:6485] cluster_state: ok

All nodes "cluster_state" are SAME: ok

Get cluster used memory

redis-cluster-tool -a 127.0.0.1:6479 -C cluster_used_memory -r master     
master[127.0.0.1:6479] used_memory: 2457304 (2 MB 33.33%)
master[127.0.0.1:6482] used_memory: 2457304 (2 MB 33.33%)
master[127.0.0.1:6485] used_memory: 2457304 (2 MB 33.33%)

Cluster total "used_memory" : 7371912 (7 MB)

Flush cluster

redis-cluster-tool -a 127.0.0.1:6479 -C flushall -s
Do you really want to execute the "flushall"?
please input "yes" or "no" :
yes

All nodes "flushall" are OK

Get config value from every node in cluster

redis-cluster-tool -a 127.0.0.1:6479 -C "cluster_config_get maxmemory" -r master
master[127.0.0.1:6479] maxmemory: 116391936 (111 MB)
master[127.0.0.1:6482] maxmemory: 116391936 (111 MB)
master[127.0.0.1:6485] maxmemory: 116391936 (111 MB)

All nodes "maxmemory" are SAME: 116391936 (111 MB)
Cluster total maxmemory: 349175808 (333 MB)

Set config value on every node in cluster

redis-cluster-tool -a 127.0.0.1:6479 -C "cluster_config_set maxmemory 10000000" -s
Do you really want to execute the "cluster_config_set"?
please input "yes" or "no" :
yes

All nodes "config" are OK

Recheck new value

redis-cluster-tool -a 127.0.0.1:6479 -C "cluster_config_get maxmemory" -r master
master[127.0.0.1:6479] maxmemory: 10000000 (9 MB)
master[127.0.0.1:6482] maxmemory: 10000000 (9 MB)
master[127.0.0.1:6485] maxmemory: 10000000 (9 MB)

All nodes "maxmemory" are SAME: 10000000 (9 MB)
Cluster total maxmemory: 30000000 (28 MB)

Delete keys in cluster

redis-cluster-tool -a 127.0.0.1:6479 -C "del_keys 1*"
Do you really want to execute the "del_keys"?
please input "yes" or "no" :
yes
delete keys job is running...
delete keys job finished, deleted: 999999 keys, used: 4 s

End result is 9x redis server cluster consisting of 3x sets of Redis master + 2 slaves.

Example of redis port 6479 master with port 6480 and 6481 redis slaves

redis-cli -h 127.0.0.1 -p 6479 INFO REPLICATION
# Replication
role:master
connected_slaves:2
slave0:ip=127.0.0.1,port=6480,state=online,offset=1274,lag=0
slave1:ip=127.0.0.1,port=6481,state=online,offset=1274,lag=0
master_repl_offset:1274
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:2
repl_backlog_histlen:1273

redis-cli -h 127.0.0.1 -p 6480 INFO REPLICATION  
# Replication
role:slave
master_host:127.0.0.1
master_port:6479
master_link_status:up
master_last_io_seconds_ago:2
master_sync_in_progress:0
slave_repl_offset:1358
slave_priority:100
slave_read_only:1
connected_slaves:0
master_repl_offset:0
repl_backlog_active:0
repl_backlog_size:1048576
repl_backlog_first_byte_offset:0
repl_backlog_histlen:0

redis-cli -h 127.0.0.1 -p 6481 INFO REPLICATION 
# Replication
role:slave
master_host:127.0.0.1
master_port:6479
master_link_status:up
master_last_io_seconds_ago:8
master_sync_in_progress:0
slave_repl_offset:1358
slave_priority:100
slave_read_only:1
connected_slaves:0
master_repl_offset:0
repl_backlog_active:0
repl_backlog_size:1048576
repl_backlog_first_byte_offset:0
repl_backlog_histlen:0

Example of redis port 6482 master with port 6483 and 6484 redis slaves

redis-cli -h 127.0.0.1 -p 6482 INFO REPLICATION 
# Replication
role:master
connected_slaves:2
slave0:ip=127.0.0.1,port=6483,state=online,offset=1498,lag=0
slave1:ip=127.0.0.1,port=6484,state=online,offset=1498,lag=0
master_repl_offset:1498
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:2
repl_backlog_histlen:1497

redis-cli -h 127.0.0.1 -p 6483 INFO REPLICATION 
# Replication
role:slave
master_host:127.0.0.1
master_port:6482
master_link_status:up
master_last_io_seconds_ago:8
master_sync_in_progress:0
slave_repl_offset:1498
slave_priority:100
slave_read_only:1
connected_slaves:0
master_repl_offset:0
repl_backlog_active:0
repl_backlog_size:1048576
repl_backlog_first_byte_offset:0
repl_backlog_histlen:0

redis-cli -h 127.0.0.1 -p 6484 INFO REPLICATION 
# Replication
role:slave
master_host:127.0.0.1
master_port:6482
master_link_status:up
master_last_io_seconds_ago:1
master_sync_in_progress:0
slave_repl_offset:1512
slave_priority:100
slave_read_only:1
connected_slaves:0
master_repl_offset:0
repl_backlog_active:0
repl_backlog_size:1048576
repl_backlog_first_byte_offset:0
repl_backlog_histlen:0

Cluster node info

redis-cli -h 127.0.0.1 -p 6479 -c cluster nodes | sort -k2
3d96c3b1a9413ddbe86b76fe647d978c59667fd9 127.0.0.1:6479 myself,master - 0 0 1 connected 0-5461
f85f542abf5428a7733a8a61aa2f3d3e3753245a 127.0.0.1:6480 slave 3d96c3b1a9413ddbe86b76fe647d978c59667fd9 0 1489600758505 1 connected
49f574a996f0cf54c7925b87c87aa6d9b8bcde1c 127.0.0.1:6481 slave 3d96c3b1a9413ddbe86b76fe647d978c59667fd9 0 1489600758505 5 connected
a902dd4f58687378950cd7dcb054c4813cca1f69 127.0.0.1:6482 master - 0 1489600757500 6 connected 5462-10922
1b9b164150e679c71abdad31d2e0c3529290f5b8 127.0.0.1:6483 slave a902dd4f58687378950cd7dcb054c4813cca1f69 0 1489600759009 7 connected
d24ebd19b8c509401c6b14e126d88ac208235c12 127.0.0.1:6484 slave a902dd4f58687378950cd7dcb054c4813cca1f69 0 1489600759009 6 connected
1e9a870450fb67fe96e78e5c1e28fe7a0ffcfbae 127.0.0.1:6485 master - 0 1489600757500 8 connected 10923-16383
a0ff921249b308dabea33eba5449ebdea0acafed 127.0.0.1:6486 slave 1e9a870450fb67fe96e78e5c1e28fe7a0ffcfbae 0 1489600756994 8 connected
4070795b598a586827d170b341dbd685b19e0ed0 127.0.0.1:6487 slave 1e9a870450fb67fe96e78e5c1e28fe7a0ffcfbae 0 1489600758505 8 connected

Test the redis cluster

redis-cli -h 127.0.0.1 -p 6479 -c set foo bar
OK

redis-cli -h 127.0.0.1 -p 6479 -c get foo
"bar"

redis-cli -h 127.0.0.1 -p 6480 -c get foo  
"bar"

redis-cli -h 127.0.0.1 -p 6481 -c get foo 
"bar"

redis-cli -h 127.0.0.1 -p 6482 -c get foo  
"bar"

redis-cli -h 127.0.0.1 -p 6483 -c get foo 
"bar"

redis-cli -h 127.0.0.1 -p 6484 -c get foo 
"bar"

redis-cli -h 127.0.0.1 -p 6485 -c get foo 
"bar"

redis-cli -h 127.0.0.1 -p 6486 -c get foo 
"bar"

redis-cli -h 127.0.0.1 -p 6487 -c get foo 
"bar"

redis-keys.sh

redis-keys.sh script allows you to list all redis cache keys for a specific redis dataabase name or for all redis databases as well as purge a specific redis database. Below is an example from Centmin Mod's centmin.sh menu option 22 Wordpress auto installer's Redis Nginx level full HTML page caching setup querying the cached full HTML Wordpress pages and listing their redis cache expiry TTL values in seconds and when you purge the redis database number = 0.

./redis-keys.sh

Usage:

./redis-keys.sh get {redis_db_number}
./redis-keys.sh purge {redis_db_number}

./redis-keys.sh get 0
---
redis key: nginx-cache:httpsGETyourdomain.com/
redis expiry ttl: (integer) 3588
---
redis key: nginx-cache:httpsGETyourdomain.com/1/hello-world/
redis expiry ttl: (integer) 3598
---
redis key: nginx-cache:httpsGETyourdomain.com/category/news/
redis expiry ttl: (integer) 3593
---
redis key: nginx-cache:httpsGETyourdomain.com/5/first-post/
redis expiry ttl: (integer) 3589

./redis-keys.sh purge 0
Purging redis database 0: OK

./redis-keys.sh get 0
---
redis key: 
redis expiry ttl: (integer) -2