Introduction
I was recently asked to implement Redis-Cluster This cluster will spawn 3 master and 3 slave nodes.
Cluster
I have used the docker-compose.yml from Bitnami:
version: '2'
services:
r01:
image: docker.io/bitnami/redis-cluster:6.2
hostname: r01
container_name: r01
environment:
- ALLOW_EMPTY_PASSWORD=yes
- REDIS_NODES=r01 r02 r03 r04 r05 r06
networks:
- redis_net
r02:
image: docker.io/bitnami/redis-cluster:6.2
hostname: r02
container_name: r02
environment:
- ALLOW_EMPTY_PASSWORD=yes
- REDIS_NODES=r01 r02 r03 r04 r05 r06
networks:
- redis_net
r03:
image: docker.io/bitnami/redis-cluster:6.2
hostname: r03
container_name: r03
environment:
- ALLOW_EMPTY_PASSWORD=yes
- REDIS_NODES=r01 r02 r03 r04 r05 r06
networks:
- redis_net
r04:
image: docker.io/bitnami/redis-cluster:6.2
hostname: r04
container_name: r04
environment:
- ALLOW_EMPTY_PASSWORD=yes
- REDIS_NODES=r01 r02 r03 r04 r05 r06
networks:
- redis_net
r05:
image: docker.io/bitnami/redis-cluster:6.2
hostname: r05
container_name: r05
environment:
- ALLOW_EMPTY_PASSWORD=yes
- REDIS_NODES=r01 r02 r03 r04 r05 r06
networks:
- redis_net
r06:
image: docker.io/bitnami/redis-cluster:6.2
hostname: r06
container_name: r06
depends_on:
- r01
- r02
- r03
- r04
- r05
environment:
- ALLOW_EMPTY_PASSWORD=yes
- REDIS_NODES=r01 r02 r03 r04 r05 r06
- REDIS_CLUSTER_REPLICAS=1
- REDIS_CLUSTER_CREATOR=yes
networks:
- redis_net
networks:
redis_net:
driver: bridgeThis will launch 6 containers:
$ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 4a2d11bd1275 bitnami/redis-cluster:6.2 "/opt/bitnami/script…" 19 seconds ago Up 18 seconds 6379/tcp r06 702d098a2c9c bitnami/redis-cluster:6.2 "/opt/bitnami/script…" 20 seconds ago Up 19 seconds 6379/tcp r03 878870c4e8e6 bitnami/redis-cluster:6.2 "/opt/bitnami/script…" 20 seconds ago Up 18 seconds 6379/tcp r02 a8d0d5302e1c bitnami/redis-cluster:6.2 "/opt/bitnami/script…" 20 seconds ago Up 19 seconds 6379/tcp r01 9dd772da1aee bitnami/redis-cluster:6.2 "/opt/bitnami/script…" 20 seconds ago Up 18 seconds 6379/tcp r04 263a280f180a bitnami/redis-cluster:6.2 "/opt/bitnami/script…" 20 seconds ago Up 18 seconds 6379/tcp r05
We can now login to one of the containers:
$ redis-cluster % docker exec -it r01 /bin/bash I have no name!@r01:/$
You can test the cluster settings:
$ redis-cli 127.0.0.1:6379> cluster info cluster_state:ok cluster_slots_assigned:16384 cluster_slots_ok:16384 cluster_slots_pfail:0 cluster_slots_fail:0 cluster_known_nodes:6 cluster_size:3 cluster_current_epoch:6 cluster_my_epoch:1 cluster_stats_messages_ping_sent:52 cluster_stats_messages_pong_sent:55 cluster_stats_messages_sent:107 cluster_stats_messages_ping_received:50 cluster_stats_messages_pong_received:52 cluster_stats_messages_meet_received:5 cluster_stats_messages_received:107
You can check the cluster nodes status:
$ cluster nodes 535a218f52e42503bfe306c82dc6308b1bdb0cd5 172.21.0.3:6379@16379 myself,master - 0 1634935181000 3 connected 10923-16383 3dec2af9999f386b0212104f08badd3124a43535 172.21.0.4:6379@16379 slave 535a218f52e42503bfe306c82dc6308b1bdb0cd5 0 1634935181702 3 connected 1b554ca155d2008b319b0f3117e970a446169977 172.21.0.5:6379@16379 slave b02f0d075b12ac25c16230b0ce14f9482ec251e1 0 1634935180692 1 connected 145398bae4b7347c382fb8417fb67d35f0e77715 172.21.0.7:6379@16379 slave 9932d062c2f355aab0565758b0d686b92a20c8f9 0 1634935180000 2 connected b02f0d075b12ac25c16230b0ce14f9482ec251e1 172.21.0.2:6379@16379 master - 0 1634935179682 1 connected 0-5460 9932d062c2f355aab0565758b0d686b92a20c8f9 172.21.0.6:6379@16379 master - 0 1634935182677 2 connected 5461-10922
You can run some set and get:
172.21.0.3:6379> set hi "hello"
-> Redirected to slot [16140] located at 172.21.0.3:6379
OK
172.21.0.3:6379> get hi
"hello"
172.21.0.3:6379>We can test the same on other nodes as well to test if the cluster is working by et hi on nodes r2-r6.
Happy Coding !!!
