redis sentinel 5.0.5 之二：setup sentinel

￡神魔★判官ぃ 2023-02-10 03:43 20阅读 0赞

os: centos7.4  
redis:5.0.5

192.168.56.101  sent1
    192.168.56.102  sent2
    192.168.56.103  sent3
    192.168.56.104  red1
    192.168.56.105  red2
    192.168.56.106  red3

**Redis-Sentinel** 是Redis官方推荐的高可用性(HA)解决方案，当Redis做Master-slave的高可用方案时，假如master宕机了，Redis-Sentinel 就能实现自动切换  
而 Redis-sentinel 本身也是一个独立运行的进程，它能监控多个master-slave集群，发现master宕机后能进行自动切换。

首先 sentinel 必须是高可用的

# os 设置 #

参考<<[centos 7.x 安装 redis 的优化设置][centos 7.x _ redis]>>

# redis 软件安装 #

参考<<[redis cluster 4.0.9 之一: make && make install][redis cluster 4.0.9 _ make _ make install]>>

# Redis-Sentinel 集群 #

sent1,sent2,sent3 三个节点创建成一个 Redis-Sentinel 集群

sent1,sent2,sent3 参数文件一致

# vi /etc/redis/sentinel.conf
    
    port 26379
    daemonize yes
    pidfile /var/run/redis-sentinel.pid
    logfile /var/log/redis/redis-sentinel.log
    dir /var/lib/redis/sentinel-data/
    sentinel monitor mymaster 192.168.56.104 6379 2
    sentinel down-after-milliseconds mymaster 30000
    sentinel parallel-syncs mymaster 1
    sentinel failover-timeout mymaster 180000
    sentinel deny-scripts-reconfig yes

启动 redis-sentinel

# redis-sentinel /etc/redis/sentinel.conf

sent3 节点查看日志

# cat /var/log/redis/redis-sentinel.log 
    2379:X 19 May 2020 20:21:11.442 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
    2379:X 19 May 2020 20:21:11.442 # Redis version=5.0.5, bits=64, commit=00000000, modified=0, pid=2379, just started
    2379:X 19 May 2020 20:21:11.442 # Configuration loaded
    2380:X 19 May 2020 20:21:11.445 # Not listening to IPv6: unsupproted
    2380:X 19 May 2020 20:21:11.446 * Running mode=sentinel, port=26379.
    2380:X 19 May 2020 20:21:11.512 # Sentinel ID is 6d0fdc4a491934cb7b92243fd2c50cee7db7c039
    2380:X 19 May 2020 20:21:11.512 # +monitor master mymaster 192.168.56.104 6379 quorum 2
    2380:X 19 May 2020 20:21:11.514 * +slave slave 192.168.56.105:6379 192.168.56.105 6379 @ mymaster 192.168.56.104 6379
    2380:X 19 May 2020 20:21:11.519 * +slave slave 192.168.56.106:6379 192.168.56.106 6379 @ mymaster 192.168.56.104 6379
    2380:X 19 May 2020 20:21:12.362 * +sentinel sentinel 59ea217b425689a09c0fd8619fc2ae4c152f361e 192.168.56.101 26379 @ mymaster 192.168.56.104 6379
    2380:X 19 May 2020 20:21:13.133 * +sentinel sentinel fe02b1a3befa53765c5f6d7c3e16f20352eac5de 192.168.56.102 26379 @ mymaster 192.168.56.104 6379

# redis-cli -h 192.168.56.101 -p 26379 info Sentinel
    # Sentinel
    sentinel_masters:1
    sentinel_tilt:0
    sentinel_running_scripts:0
    sentinel_scripts_queue_length:0
    sentinel_simulate_failure_flags:0
    master0:name=mymaster,status=ok,address=192.168.56.104:6379,slaves=2,sentinels=3

slaves=2 说明 redis 有两个 salve  
sentinels=3 说明有3个sentinel

# redis master down #

red1 节点kill 掉 redis 进程模拟灾难

# ps -ef|grep -i redis
    root      4949     1  0 20:02 ?        00:00:01 redis-server 0.0.0.0:6379
    root      5159  1516  0 20:24 pts/0    00:00:00 grep --color=auto -i redis
     
    # kill 4949
    
    # ps -ef|grep -i redis
    root      5179  1516  0 20:25 pts/0    00:00:00 grep --color=auto -i redis

发现 red3 节点 提升成了 master

127.0.0.1:6379> info replication
    # Replication
    role:master
    connected_slaves:1
    slave0:ip=192.168.56.105,port=6379,state=online,offset=258673,lag=2
    master_replid:36029295efc4b2d2d08067cd3fd6e7a29062af55
    master_replid2:fb48317c3610740c9f6c04ff7b08768beec9bac8
    master_repl_offset:258830
    second_repl_offset:250472
    repl_backlog_active:1
    repl_backlog_size:1048576
    repl_backlog_first_byte_offset:453
    repl_backlog_histlen:258378

这是把 red1 节点的 redis 启动后自动变为了 salve。

# redis-server /etc/redis/redis.conf
    
    # redis-cli
    127.0.0.1:6379> info replication
    # Replication
    role:slave
    master_host:192.168.56.106
    master_port:6379
    master_link_status:up
    master_last_io_seconds_ago:0
    master_sync_in_progress:0
    slave_repl_offset:284977
    slave_priority:100
    slave_read_only:1
    connected_slaves:0
    master_replid:36029295efc4b2d2d08067cd3fd6e7a29062af55
    master_replid2:0000000000000000000000000000000000000000
    master_repl_offset:284977
    second_repl_offset:-1
    repl_backlog_active:1
    repl_backlog_size:1048576
    repl_backlog_first_byte_offset:279064
    repl_backlog_histlen:5914

期间 sentinel 的日志

2370:X 19 May 2020 20:26:14.451 # +sdown master mymaster 192.168.56.104 6379
    2370:X 19 May 2020 20:26:14.611 # +new-epoch 1
    2370:X 19 May 2020 20:26:14.616 # +vote-for-leader fe02b1a3befa53765c5f6d7c3e16f20352eac5de 1
    2370:X 19 May 2020 20:26:14.616 # +odown master mymaster 192.168.56.104 6379 #quorum 3/2
    2370:X 19 May 2020 20:26:14.616 # Next failover delay: I will not start a failover before Tue May 19 20:32:15 2020
    2370:X 19 May 2020 20:26:15.883 # +config-update-from sentinel fe02b1a3befa53765c5f6d7c3e16f20352eac5de 192.168.56.102 26379 @ mymaster 192.168.56.104 6379
    2370:X 19 May 2020 20:26:15.883 # +switch-master mymaster 192.168.56.104 6379 192.168.56.106 6379
    2370:X 19 May 2020 20:26:15.884 * +slave slave 192.168.56.105:6379 192.168.56.105 6379 @ mymaster 192.168.56.106 6379
    2370:X 19 May 2020 20:26:15.884 * +slave slave 192.168.56.104:6379 192.168.56.104 6379 @ mymaster 192.168.56.106 6379
    2370:X 19 May 2020 20:26:46.189 # +sdown slave 192.168.56.104:6379 192.168.56.104 6379 @ mymaster 192.168.56.106 6379
    2370:X 19 May 2020 20:28:21.572 # -sdown slave 192.168.56.104:6379 192.168.56.104 6379 @ mymaster 192.168.56.106 6379
    2370:X 19 May 2020 20:28:31.597 * +convert-to-slave slave 192.168.56.104:6379 192.168.56.104 6379 @ mymaster 192.168.56.106 6379

2387:X 19 May 2020 20:26:14.594 # +sdown master mymaster 192.168.56.104 6379
    2387:X 19 May 2020 20:26:14.696 # +odown master mymaster 192.168.56.104 6379 #quorum 2/2
    2387:X 19 May 2020 20:26:14.696 # +new-epoch 1
    2387:X 19 May 2020 20:26:14.696 # +try-failover master mymaster 192.168.56.104 6379
    2387:X 19 May 2020 20:26:14.728 # +vote-for-leader fe02b1a3befa53765c5f6d7c3e16f20352eac5de 1
    2387:X 19 May 2020 20:26:14.760 # 59ea217b425689a09c0fd8619fc2ae4c152f361e voted for fe02b1a3befa53765c5f6d7c3e16f20352eac5de 1
    2387:X 19 May 2020 20:26:14.761 # 6d0fdc4a491934cb7b92243fd2c50cee7db7c039 voted for fe02b1a3befa53765c5f6d7c3e16f20352eac5de 1
    2387:X 19 May 2020 20:26:14.807 # +elected-leader master mymaster 192.168.56.104 6379
    2387:X 19 May 2020 20:26:14.807 # +failover-state-select-slave master mymaster 192.168.56.104 6379
    2387:X 19 May 2020 20:26:14.982 # +selected-slave slave 192.168.56.106:6379 192.168.56.106 6379 @ mymaster 192.168.56.104 6379
    2387:X 19 May 2020 20:26:14.982 * +failover-state-send-slaveof-noone slave 192.168.56.106:6379 192.168.56.106 6379 @ mymaster 192.168.56.104 6379
    2387:X 19 May 2020 20:26:15.094 * +failover-state-wait-promotion slave 192.168.56.106:6379 192.168.56.106 6379 @ mymaster 192.168.56.104 6379
    2387:X 19 May 2020 20:26:15.810 # +promoted-slave slave 192.168.56.106:6379 192.168.56.106 6379 @ mymaster 192.168.56.104 6379
    2387:X 19 May 2020 20:26:15.810 # +failover-state-reconf-slaves master mymaster 192.168.56.104 6379
    2387:X 19 May 2020 20:26:16.026 * +slave-reconf-sent slave 192.168.56.105:6379 192.168.56.105 6379 @ mymaster 192.168.56.104 6379
    2387:X 19 May 2020 20:26:17.035 # -odown master mymaster 192.168.56.104 6379
    2387:X 19 May 2020 20:26:17.036 * +slave-reconf-inprog slave 192.168.56.105:6379 192.168.56.105 6379 @ mymaster 192.168.56.104 6379
    2387:X 19 May 2020 20:26:18.038 * +slave-reconf-done slave 192.168.56.105:6379 192.168.56.105 6379 @ mymaster 192.168.56.104 6379
    2387:X 19 May 2020 20:26:18.105 # +failover-end master mymaster 192.168.56.104 6379
    2387:X 19 May 2020 20:26:18.105 # +switch-master mymaster 192.168.56.104 6379 192.168.56.106 6379
    2387:X 19 May 2020 20:26:18.106 * +slave slave 192.168.56.105:6379 192.168.56.105 6379 @ mymaster 192.168.56.106 6379
    2387:X 19 May 2020 20:26:18.106 * +slave slave 192.168.56.104:6379 192.168.56.104 6379 @ mymaster 192.168.56.106 6379
    2387:X 19 May 2020 20:26:48.224 # +sdown slave 192.168.56.104:6379 192.168.56.104 6379 @ mymaster 192.168.56.106 6379
    2387:X 19 May 2020 20:28:22.474 # -sdown slave 192.168.56.104:6379 192.168.56.104 6379 @ mymaster 192.168.56.106 6379

2380:X 19 May 2020 20:26:14.221 # +sdown master mymaster 192.168.56.104 6379
    2380:X 19 May 2020 20:26:14.690 # +new-epoch 1
    2380:X 19 May 2020 20:26:14.695 # +vote-for-leader fe02b1a3befa53765c5f6d7c3e16f20352eac5de 1
    2380:X 19 May 2020 20:26:15.356 # +odown master mymaster 192.168.56.104 6379 #quorum 3/2
    2380:X 19 May 2020 20:26:15.356 # Next failover delay: I will not start a failover before Tue May 19 20:32:15 2020
    2380:X 19 May 2020 20:26:15.961 # +config-update-from sentinel fe02b1a3befa53765c5f6d7c3e16f20352eac5de 192.168.56.102 26379 @ mymaster 192.168.56.104 6379
    2380:X 19 May 2020 20:26:15.961 # +switch-master mymaster 192.168.56.104 6379 192.168.56.106 6379
    2380:X 19 May 2020 20:26:15.961 * +slave slave 192.168.56.105:6379 192.168.56.105 6379 @ mymaster 192.168.56.106 6379
    2380:X 19 May 2020 20:26:15.962 * +slave slave 192.168.56.104:6379 192.168.56.104 6379 @ mymaster 192.168.56.106 6379
    2380:X 19 May 2020 20:26:46.059 # +sdown slave 192.168.56.104:6379 192.168.56.104 6379 @ mymaster 192.168.56.106 6379
    2380:X 19 May 2020 20:28:22.478 # -sdown slave 192.168.56.104:6379 192.168.56.104 6379 @ mymaster 192.168.56.106 6379

参考:

[centos 7.x _ redis]: https://blog.csdn.net/ctypyb2002/article/details/105975349
[redis cluster 4.0.9 _ make _ make install]: https://blog.csdn.net/ctypyb2002/article/details/80367259