Docker的redis主从配置实践

Docker的redis主从配置实践

Docker下redis的主从配置_lzy_yuan的博客-CSDN博客_docker redis 主从配置

前言

本节主要实践redis集群分类重点如下两个

• 主从复制 Replication
• 高可用 Sentinel

理论知识讲解在：Redis集群配置

Docker redis 集群搭建 1、拉取redis镜像

[tcy@tcy1 ~]$ docker pull latest

2、启动3个redis容器服务，分别使用到6379、6380、6381端口

docker run --name redis-6379 -p 6379:6379 -d redis

docker run --name redis-6380 -p 6380:6379 -d redis

docker run --name redis-6381 -p 6381:6379 -d redis

3、查看容器

[root@iZuf64res1ona9ad2ddsejZ /]# docker ps
ConTAINER ID   IMAGE     COMMAND                  CREATED         STATUS         PORTS                                       NAMES
b2cd780565ea   redis     "docker-entrypoint.s…"   6 minutes ago   Up 6 minutes   0.0.0.0:6381->6379/tcp, :::6381->6379/tcp   redis-6381
c77bb120d46b   redis     "docker-entrypoint.s…"   6 minutes ago   Up 6 minutes   0.0.0.0:6380->6379/tcp, :::6380->6379/tcp   redis-6380
e686c631435d   redis     "docker-entrypoint.s…"   6 minutes ago   Up 6 minutes   0.0.0.0:6379->6379/tcp, :::6379->6379/tcp   redis-6379

4、测试容器，成功

docker exec -it redis-6379 redis-cli：进入容器

[root@tcy1 tcy]# docker exec -it redis-6379 redis-cli
127.0.0.1:6379> set my 123
OK
127.0.0.1:6379> get my
"123"
127.0.0.1:6379> hset demo my 123
OK
127.0.0.1:6379> hget demo my
"123"
127.0.0.1:6379> quit
[root@tcy1 tcy]#

5、开始redis集群配置 5.1、看容器内网的ip地址

[root@tcy1 tcy]# docker inspect redis-6379 | grep IPAddress
            "SecondaryIPAddresses": null,
            "IPAddress": "172.17.0.2",
                    "IPAddress": "172.17.0.2",

3个redis的内网ip地址为：

redis-6379：172.17.0.2:6379
redis-6380：172.17.0.3:6379
redis-6381：172.17.0.4:6379

5.2、进入docker容器内部，查看当前redis角色（主还是从）

docker exec -it redis-6379 redis-cli
info replication
[root@iZuf64res1ona9ad2ddsejZ /]# docker exec -it redis-6379 redis-cli
127.0.0.1:6379> info replication
# Replication
role:master
connected_slaves:0
master_failover_state:no-failover
master_replid:6344cee02a6be76f645801653e90e37f6a3e707b
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:0
second_repl_offset:-1
repl_backlog_active:0
repl_backlog_size:1048576
repl_backlog_first_byte_offset:0
repl_backlog_histlen:0
127.0.0.1:6379> 
127.0.0.1:6379> exit 
exit

目前三个都是master状态（即主人状态）

5.3、使用redis-cli命令修改redis-6380、redis-6381的主机为172.17.0.1:6379

[root@iZuf64res1ona9ad2ddsejZ /]# docker exec -it redis-6380 redis-cli
127.0.0.1:6379> SLAVEOF 172.17.0.2 6379
OK
127.0.0.1:6379> exit
exit
[root@iZuf64res1ona9ad2ddsejZ /]# docker exec -it redis-6381 redis-cli
127.0.0.1:6379> slaveof 172.17.0.2 6379
OK
127.0.0.1:6379> exit
exit

5.4、查看主从配置是否成功

查看redis-6379是否已经拥有2个从机，connected_slaves:2，是的

[root@iZuf64res1ona9ad2ddsejZ /]# docker exec -it redis-6379 redis-cli
127.0.0.1:6379> info replication
# Replication
role:master
connected_slaves:2
slave0:ip=172.17.0.3,port=6379,state=online,offset=154,lag=1
slave1:ip=172.17.0.4,port=6379,state=online,offset=154,lag=0
master_failover_state:no-failover
master_replid:97cf8fd7f54da1653a173900b032ae3becfdceac
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:154
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:1
repl_backlog_histlen:154
127.0.0.1:6379> exit
exit

Sentinel哨兵集群配置

这里将在三个docker上各配置一个sentinel哨兵，以实现哨兵的高可用。当然也可以只实现一个或者两个哨兵。

1.哨兵配置文件

进入3台redis容器内部进行配置，在容器根目录里面创建sentinel.conf文件（注意，这里我三台都配建立一个sentinel集群）

文件内容为如下，表示监听master 172.17.0.1 6379端口，当master出问题时，只需要一个sentinel发现就可以切换master（mymaster为命名，可任意）。

sentinel monitor mymaster 172.17.0.1 6379 1
[root@iZuf64res1ona9ad2ddsejZ /]# docker exec -it redis-6379 bash
root@e686c631435d:/data# cd / && touch sentinel.conf  
root@e686c631435d:# vim /sentinel.conf

如果出现：bash: vim: command not found

解决：

apt-get update
apt-get install vim

解决之后请记得写入内容

2.启动Redis哨兵

三个都需要启动，启动后自动构建为三个集群

root@a9fa77adc598:/# redis-sentinel /sentinel.conf
485:X 01 Jan 2022 11:11:04.231 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
485:X 01 Jan 2022 11:11:04.231 # Redis version=6.2.6, bits=64, commit=00000000, modified=0, pid=485, just started
485:X 01 Jan 2022 11:11:04.231 # Configuration loaded
485:X 01 Jan 2022 11:11:04.231 * monotonic clock: POSIX clock_gettime
                _._                                                  
           _.-``__ ''-._                                             
      _.-``    `.  `_.  ''-._           Redis 6.2.6 (00000000/0) 64 bit
  .-`` .-```.  ```/    _.,_ ''-._                                  
 (    '      ,       .-`  | `,    )     Running in sentinel mode
 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 26379
 |    `-._   `._    /     _.-'    |     PID: 485
  `-._    `-._  `-./  _.-'    _.-'                                   
 |`-._`-._    `-.__.-'    _.-'_.-'|                                  
 |    `-._`-._        _.-'_.-'    |           https://redis.io       
  `-._    `-._`-.__.-'_.-'    _.-'                                   
 |`-._`-._    `-.__.-'    _.-'_.-'|                                  
 |    `-._`-._        _.-'_.-'    |                                  
  `-._    `-._`-.__.-'_.-'    _.-'                                   
      `-._    `-.__.-'    _.-'                                       
          `-._        _.-'                                           
              `-.__.-'                                               

485:X 01 Jan 2022 11:11:04.232 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
485:X 01 Jan 2022 11:11:04.238 # Sentinel ID is e11bad57828dbb4dcbd2864d9fe3cb1c98660cc1
485:X 01 Jan 2022 11:11:04.238 # +monitor master mymaster 172.17.0.1 6379 quorum 1
485:X 01 Jan 2022 11:11:04.239 * +slave slave 172.17.0.3:6379 172.17.0.3 6379 @ mymaster 172.17.0.1 6379
485:X 01 Jan 2022 11:11:04.245 * +slave slave 172.17.0.4:6379 172.17.0.4 6379 @ mymaster 172.17.0.1 6379

Sentinel哨兵配置完毕。

3.测试

关闭Master

[tcy@tcy1 ~]$ docker stop redis-6379
redis-6379

这时，剩余的2个从机，会自动选举产生新的主机，这里选举172.17.0.2为主机。

+switch-master mymaster 172.17.0.1 6379 172.17.0.3 6379
662:X 01 Jan 2022 11:15:14.992 # +new-epoch 1
662:X 01 Jan 2022 11:15:14.995 # +vote-for-leader e11bad57828dbb4dcbd2864d9fe3cb1c98660cc1 1
662:X 01 Jan 2022 11:15:15.833 # +config-update-from sentinel e11bad57828dbb4dcbd2864d9fe3cb1c98660cc1 172.17.0.2 26379 @ mymaster 172.17.0.1 6379
662:X 01 Jan 2022 11:15:15.833 # +switch-master mymaster 172.17.0.1 6379 172.17.0.3 6379
662:X 01 Jan 2022 11:15:15.833 * +slave slave 172.17.0.1:6379 172.17.0.1 6379 @ mymaster 172.17.0.3 6379
662:X 01 Jan 2022 11:15:21.961 * +slave slave 172.17.0.2:6379 172.17.0.2 6379 @ mymaster 172.17.0.3 6379
662:X 01 Jan 2022 11:15:21.965 * +slave slave 172.17.0.4:6379 172.17.0.4 6379 @ mymaster 172.17.0.3 6379
662:X 01 Jan 2022 11:16:02.505 # +sdown slave 172.17.0.1:6379 172.17.0.1 6379 @ mymaster 172.17.0.3 6379
662:X 01 Jan 2022 11:16:02.505 # +sdown slave 172.17.0.2:6379 172.17.0.2 6379 @ mymaster 172.17.0.3 6379
662:X 01 Jan 2022 11:16:02.596 # +sdown sentinel e11bad57828dbb4dcbd2864d9fe3cb1c98660cc1 172.17.0.2 26379 @ mymaster 172.17.0.3 6379

查看172.17.0.2，变成了主机。

[root@iZuf64res1ona9ad2ddsejZ ~]# docker exec -it redis-6380 redis-cli
127.0.0.1:6379>  info replication
# Replication
role:master
connected_slaves:1
slave0:ip=172.17.0.4,port=6379,state=online,offset=55609,lag=1
master_failover_state:no-failover
master_replid:61f98261fd6306c390ebe5c9c5d3e2fee4fbb66d
master_replid2:97cf8fd7f54da1653a173900b032ae3becfdceac
master_repl_offset:55758
second_repl_offset:23959
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:1
repl_backlog_histlen:55758
127.0.0.1:6379> 

重启redis-6379查看发现redis-6379为redis-6380的从

[root@iZuf64res1ona9ad2ddsejZ ~]# docker start redis-6379
redis-6379
[root@iZuf64res1ona9ad2ddsejZ ~]# docker exec -it redis-6379 redis-cli
127.0.0.1:6379> info replication
# Replication
role:slave
master_host:172.17.0.3
master_port:6379
master_link_status:up
master_last_io_seconds_ago:1
master_sync_in_progress:0
slave_read_repl_offset:63006
slave_repl_offset:63006
slave_priority:100
slave_read_only:1
replica_announced:1
connected_slaves:0
master_failover_state:no-failover
master_replid:61f98261fd6306c390ebe5c9c5d3e2fee4fbb66d
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:63006
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:62025
repl_backlog_histlen:982
127.0.0.1:6379>