前言
在现实生产环境中我们可能会遇到一种情况，那就是系统需要从一个网段迁移到另一个网段。但是由于redis集群在创建时配置文件中是指定了每个节点的IP地址及端口的，因此在redis节点IP更换后，原有的集群也就失效了。如果要恢复原有的集群应该怎么办？如果不考虑集群数据的话，我们可以直接选择删除所有redis节点的数据文件dbfilename、持久化文件appendfilename、集群配置文件cluster-config-file，然后重建集群即可。但是大部分情况下我们是需要保留redis集群数据的，那么我们又该怎么来操作呢？下面演示下
修改node-1的redis节点配置文件redis.conf中的节点IP（或者修改整个redis集群IP网段）
[root@es-node22 ~]# cat /root/redis/node-1/conf/redis.conf port 6379 bind 0.0.0.0 cluster-enabled yes cluster-config-file nodes.conf ---》指定redis集群节点配置文件 cluster-node-timeout 5000 cluster-announce-ip 192.168.3.11 ---》可以看到node-1节点配置文件中IP已经修改了 cluster-announce-port 6379 cluster-announce-bus-port 16379 appendonly yes
查看集群状态
127.0.0.1:6379> set name tom ---》测试在redis集群中存数据时报错 -> Redirected to slot [5798] located at 192.168.3.2:6379 (error) CLUSTERDOWN The cluster is down 192.168.3.2:6379> cluster info cluster_state:fail ---》显示集群状态已关闭 cluster_slots_assigned:16384 cluster_slots_ok:10923 cluster_slots_pfail:0 cluster_slots_fail:5461 cluster_known_nodes:6 cluster_size:3 cluster_current_epoch:6 cluster_my_epoch:2 cluster_stats_messages_ping_sent:2203 cluster_stats_messages_pong_sent:392 cluster_stats_messages_meet_sent:4 cluster_stats_messages_fail_sent:4 cluster_stats_messages_sent:2603 cluster_stats_messages_ping_received:391 cluster_stats_messages_pong_received:310 cluster_stats_messages_meet_received:1 cluster_stats_messages_fail_received:1 cluster_stats_messages_received:703 192.168.3.2:6379> cluster slots ---》当前的集群状态，以数组形式展示 1) 1) (integer) 10923 2) (integer) 16383 3) 1) "192.168.3.3" 2) (integer) 6379 3) "ff0d1d636f94d9b092e6012408c1d0918e00e6ed" 4) 1) "192.168.3.4" 2) (integer) 6379 3) "2113cf366ad27ebd73585f03d368e77f03b1a2e1" 2) 1) (integer) 0 2) (integer) 5460 3) 1) "192.168.3.1" ---》可以看到集群中该节点的IP还是原来的IP 2) (integer) 6379 3) "c856c94ba8d2c55a0d176831bc85aa34a96fde88" 4) 1) "192.168.3.5" 2) (integer) 6379 3) "d92ff5984ab29370af0adeaca71e7938c0287ca5" 3) 1) (integer) 5461 2) (integer) 10922 3) 1) "192.168.3.2" 2) (integer) 6379 3) "8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3" 4) 1) "192.168.3.6" 2) (integer) 6379 3) "2108a90495c147c675328f9b8b4fa49e2b856faf"
解决
查看redis集群节点配置文件nodes.conf
[root@es-node22 ~]# cat /root/redis/node-1/data/nodes.conf c856c94ba8d2c55a0d176831bc85aa34a96fde88 192.168.3.1:6379@16379 myself,master - 0 1653743266000 1 connected 0-5460 d92ff5984ab29370af0adeaca71e7938c0287ca5 192.168.3.5:6379@16379 slave c856c94ba8d2c55a0d176831bc85aa34a96fde88 0 1653743274000 5 connected 2108a90495c147c675328f9b8b4fa49e2b856faf 192.168.3.6:6379@16379 slave 8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 0 1653743275531 6 connected 2113cf366ad27ebd73585f03d368e77f03b1a2e1 192.168.3.4:6379@16379 slave ff0d1d636f94d9b092e6012408c1d0918e00e6ed 0 1653743275531 4 connected 8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 192.168.3.2:6379@16379 master - 0 1653743275531 2 connected 5461-10922 ff0d1d636f94d9b092e6012408c1d0918e00e6ed 192.168.3.3:6379@16379 master - 0 1653743275000 3 connected 10923-16383 vars currentEpoch 6 lastVoteEpoch 0 [root@es-node22 ~]# cat /root/redis/node-2/data/nodes.conf ff0d1d636f94d9b092e6012408c1d0918e00e6ed 192.168.3.3:6379@16379 master - 0 1653743273233 3 connected 10923-16383 2113cf366ad27ebd73585f03d368e77f03b1a2e1 192.168.3.4:6379@16379 slave ff0d1d636f94d9b092e6012408c1d0918e00e6ed 0 1653743271151 4 connected c856c94ba8d2c55a0d176831bc85aa34a96fde88 192.168.3.1:6379@16379 master,fail - 1653743267074 1653743266961 1 connected 0-5460 d92ff5984ab29370af0adeaca71e7938c0287ca5 192.168.3.5:6379@16379 slave c856c94ba8d2c55a0d176831bc85aa34a96fde88 0 1653743272000 1 connected 8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 192.168.3.2:6379@16379 myself,master - 0 1653743271000 2 connected 5461-10922 2108a90495c147c675328f9b8b4fa49e2b856faf 192.168.3.6:6379@16379 slave 8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 0 1653743272194 6 connected vars currentEpoch 6 lastVoteEpoch 0
可以看到redis所有节点的集群配置文件nodes.conf中还是192.168.3.1:6379，需要修改成我们更换后的IP地址。（如果只是单个redis更换IP，就只需要修改那一个redis的IP跟端口即可；如果是所有redis节点，就修改所有redis节点IP跟端口配置）
批量修改所有redis节点nodes.conf文件中该配置
[root@es-node22 ~]# for i in $(seq 1 6); do \ > sed -i 's/192.168.3.1/192.168.3.11/' /root/redis/node-${i}/data/nodes.conf > done
查看修改后的所有redis集群nodes.conf文件
[root@es-node22 ~]# cat /root/redis/node-1/data/nodes.conf c856c94ba8d2c55a0d176831bc85aa34a96fde88 192.168.3.11:6379@16379 myself,master - 0 1653743266000 1 connected 0-5460 d92ff5984ab29370af0adeaca71e7938c0287ca5 192.168.3.5:6379@16379 slave c856c94ba8d2c55a0d176831bc85aa34a96fde88 0 1653743274000 5 connected 2108a90495c147c675328f9b8b4fa49e2b856faf 192.168.3.6:6379@16379 slave 8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 0 1653743275531 6 connected 2113cf366ad27ebd73585f03d368e77f03b1a2e1 192.168.3.4:6379@16379 slave ff0d1d636f94d9b092e6012408c1d0918e00e6ed 0 1653743275531 4 connected 8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 192.168.3.2:6379@16379 master - 0 1653743275531 2 connected 5461-10922 ff0d1d636f94d9b092e6012408c1d0918e00e6ed 192.168.3.3:6379@16379 master - 0 1653743275000 3 connected 10923-16383 vars currentEpoch 6 lastVoteEpoch 0 [root@es-node22 ~]# cat /root/redis/node-2/data/nodes.conf ff0d1d636f94d9b092e6012408c1d0918e00e6ed 192.168.3.3:6379@16379 master - 0 1653743273233 3 connected 10923-16383 2113cf366ad27ebd73585f03d368e77f03b1a2e1 192.168.3.4:6379@16379 slave ff0d1d636f94d9b092e6012408c1d0918e00e6ed 0 1653743271151 4 connected c856c94ba8d2c55a0d176831bc85aa34a96fde88 192.168.3.11:6379@16379 master,fail - 1653743267074 1653743266961 1 connected 0-5460 d92ff5984ab29370af0adeaca71e7938c0287ca5 192.168.3.5:6379@16379 slave c856c94ba8d2c55a0d176831bc85aa34a96fde88 0 1653743272000 1 connected 8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 192.168.3.2:6379@16379 myself,master - 0 1653743271000 2 connected 5461-10922 2108a90495c147c675328f9b8b4fa49e2b856faf 192.168.3.6:6379@16379 slave 8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 0 1653743272194 6 connected vars currentEpoch 6 lastVoteEpoch 0 ... ...
批量重启redis集群所有节点容器
[root@es-node22 ~]# docker restart $(docker ps | grep redis | awk '{print $1}') dcd802a160c6 6e2f628457f6 f05d3dfb9c8b 220df78836e9 31e7b232f1d1 1de91b4d4e68 [root@es-node22 ~]# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 6e2f628457f6 redis:5.0.9-alpine3.11 "docker-entrypoint.s…" 3 hours ago Up 2 hours 0.0.0.0:6376->6379/tcp, :::6376->6379/tcp, 0.0.0.0:16376->16379/tcp, :::16376->16379/tcp redis-6 f05d3dfb9c8b redis:5.0.9-alpine3.11 "docker-entrypoint.s…" 3 hours ago Up 2 hours 0.0.0.0:6375->6379/tcp, :::6375->6379/tcp, 0.0.0.0:16375->16379/tcp, :::16375->16379/tcp redis-5 220df78836e9 redis:5.0.9-alpine3.11 "docker-entrypoint.s…" 3 hours ago Up 2 hours 0.0.0.0:6374->6379/tcp, :::6374->6379/tcp, 0.0.0.0:16374->16379/tcp, :::16374->16379/tcp redis-4 31e7b232f1d1 redis:5.0.9-alpine3.11 "docker-entrypoint.s…" 3 hours ago Up 2 hours 0.0.0.0:6373->6379/tcp, :::6373->6379/tcp, 0.0.0.0:16373->16379/tcp, :::16373->16379/tcp redis-3 1de91b4d4e68 redis:5.0.9-alpine3.11 "docker-entrypoint.s…" 3 hours ago Up 2 hours 0.0.0.0:6372->6379/tcp, :::6372->6379/tcp, 0.0.0.0:16372->16379/tcp, :::16372->16379/tcp redis-2 dcd802a160c6 redis:5.0.9-alpine3.11 "docker-entrypoint.s…" 3 hours ago Up 2 hours 0.0.0.0:6371->6379/tcp, :::6371->6379/tcp, 0.0.0.0:16371->16379/tcp, :::16371->16379/tcp redis-1
重新查看redis集群状态
[root@es-node22 ~]# docker exec -it redis-1 /bin/sh ---》redis中默认没有bash解释器 /data # redis-cli -c 127.0.0.1:6379> cluster info cluster_state:ok ---》可以看到redis集群状态已经为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:236 cluster_stats_messages_pong_sent:233 cluster_stats_messages_sent:469 cluster_stats_messages_ping_received:233 cluster_stats_messages_pong_received:232 cluster_stats_messages_received:465 127.0.0.1:6379> cluster nodes c856c94ba8d2c55a0d176831bc85aa34a96fde88 192.168.3.11:6379@16379 master - 0 1653752958838 1 connected 0-5460 8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 192.168.3.2:6379@16379 myself,master - 0 1653752957000 2 connected 5461-10922 2113cf366ad27ebd73585f03d368e77f03b1a2e1 192.168.3.4:6379@16379 slave ff0d1d636f94d9b092e6012408c1d0918e00e6ed 0 1653752957804 4 connected 2108a90495c147c675328f9b8b4fa49e2b856faf 192.168.3.6:6379@16379 slave 8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 0 1653752957086 6 connected ff0d1d636f94d9b092e6012408c1d0918e00e6ed 192.168.3.3:6379@16379 master - 0 1653752958000 3 connected 10923-16383 d92ff5984ab29370af0adeaca71e7938c0287ca5 192.168.3.5:6379@16379 slave c856c94ba8d2c55a0d176831bc85aa34a96fde88 0 1653752958529 1 connected 127.0.0.1:6379> cluster slots 1) 1) (integer) 5461 2) (integer) 10922 3) 1) "192.168.3.2" 2) (integer) 6379 3) "8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3" 4) 1) "192.168.3.6" 2) (integer) 6379 3) "2108a90495c147c675328f9b8b4fa49e2b856faf" 2) 1) (integer) 0 2) (integer) 5460 3) 1) "192.168.3.11" ---》可以看到集群中该节点的IP已经为修改后的IP 2) (integer) 6379 3) "c856c94ba8d2c55a0d176831bc85aa34a96fde88" 4) 1) "192.168.3.5" 2) (integer) 6379 3) "d92ff5984ab29370af0adeaca71e7938c0287ca5" 3) 1) (integer) 10923 2) (integer) 16383 3) 1) "192.168.3.3" 2) (integer) 6379 3) "ff0d1d636f94d9b092e6012408c1d0918e00e6ed" 4) 1) "192.168.3.4" 2) (integer) 6379 3) "2113cf366ad27ebd73585f03d368e77f03b1a2e1"
总结
在redis集群节点更换IP地址后，只需要修改所有redis节点集群配置cluster-config-file指定的配置文件中的IP地址为新更换的IP地址（网段），修改完成后批量重启所有redis节点后，redis集群即可自动恢复为OK状态。
