This project will help your learn how to establish redis-cluster by shell and docker compose.
redis-cluster-docker-cheatsheat
├── README.md
├── master-slave
│ └── docker-compose.yml
├── master-slave-sentinel
│ ├── docker-compose.yml
│ └── sentinel
│ └── sentinel.conf
└── redis-cluster
├── docker-compose.yml
├── needToRun.sh
└── redis-cluster.tmpl
- Clone the repository.
$ mkdir redis-cluster && cd redis-cluster
$ git clone https://github.com/ChickenBenny/redis-cluster-sentinel-docker
- Choose the structure you want to build, and use docker compose in the folder to build the database.
Master-slave => It contain one master and two slave example. If you want to build the sturcture with more slave, take a look at the master-slave chapter.
Master-slave-sentinel => It contain one master and two slave structure with three sentinels example. If you want to build the sturcture with more slaves or sentinels, take a look at the master-slave-sentinel chapter.
Redis-cluster => It contain three master slave sturcture example. If you want to build the cluster with more master slave structure, take a look at the redis cluster chapter.
The stucture need one master and N slaves, remember the slave container youe need to add --slaveof
${name of master container}
${master expose port}
.
Check the structure
- Check whether all the container is built.
$ docker ps
- Enter redis-master container and check the replications status. The role should be 'master' and the connect slave should be '2'.
$ docker exec -it redis-master sh // Enter the container
$ redis-cli // Connect the redis server
127.0.0.1:6379> info replication
- Enter redis-slave container and check the replications status. The role should be 'slave' and the master host should be
${redis-master container name}
.
If you want to add sentinel in your master slave structure, you need to add sentinel folder and setting the config first.
- sentinel config
port 5000
sentinel monitor mymaster redis-master 6379 2
sentinel down-after-milliseconds mymaster 5000
sentinel failover-timeout mymaster 60000
sentinel parallel-syncs mymaster 1
port
The sentinel runs on which port in the container.sentinel monitor <master-group-name> <ip> <port> <quorum>
The quorum is the number of Sentinels that need to agree about the fact the master is not reachable, and eventually start a failover procedure. The quorum is only used to detect the failure!!sentinel <option_name> <master_name> <option_value>
down-after-milliseconds is the time in milliseconds an instance should not be reachable. parallel-syncs sets the number of replicas that can be reconfigured to use the new master after a failover at the same time.
Check the structure
- Check whether sentinels is built and check the monitoring information.
$ docker exec -it redis-sentinel1 sh
$ redis-cli -p 5000
127.0.0.1:5000 > info sentinel
- Try to stop the master container and check whether sentinel switch the new master.
$ docker stop redis-master
- Go to the slave container and check the role and replication information. One of the slave should be change to master, and the connect slave should be 1.
- Shell
Important : you should find your ip first and type in the shell script.
If you want to build more db, you can change {7001..
${7001 + N you wanted}
}.
#!/bin/bash
ip=${your ip}
for port in {7001..7006};
do
mkdir -p ./${port}/conf && PORT=${port} IP=${ip} envsubst < ./redis-cluster.tmpl > ./${port}/conf/redis.conf;
done
- Redis-cluster.tmpl
port ${PORT}
protected-mode no
cluster-enabled yes
cluster-config-file nodes.conf
cluster-node-timeout 5000
cluster-announce-ip ${IP}
cluster-announce-port ${PORT}
cluster-announce-bus-port 1${PORT}
appendonly yes
- docker compose The cluster creat command I wrote in redis-1 and you can use docker-compose up to build the cluster.
$ export IP=${your ip}
$ docker-compose up
Check the structure
-
Check the docker compose log information, whether the cluster is connect successfully.
-
Go to redis-1 container and check the cluster info, the cluster status should be 'OK' and the cluster size should be 3.
$ docker exec -it redis-1 sh
$ redis-cli -p 7001 -c
127.0.0.1:7001> cluster info
- You can also go to other container to connect the cluster.
redis-cli -p ${container ip} -c
If you want to learn more about redis, check out my medium article.
- Redis introduction : https://blog.devops.dev/redis-introduction-from-zero-to-hero-part-i-7c13e63170f5
- Redis persistence and cap theorem : https://blog.devops.dev/redis-persistence-and-cap-theorem-from-zero-to-hero-part-ii-91eaedf58d79
- Redis structure with docker : https://blog.devops.dev/redis-cluster-and-sentinel-with-docker-from-zero-to-hero-part-iv-63ba9d196cc3