【Redis】Setninel 哨兵机制
一、Sentinel 哨兵工作原理
Redis在2.6+以后引入哨兵机制，在2.8版本后趋于稳定状态，在生产环境中建议使用2.8版本以上的sentinel服务。sentinel集群用于监控redis集群中Master节点工作状态，在Master节点发生故障时，可以实现主从切换，保证系统的高可用。- 哨兵（Sentinel）是一个分布式集群架构，可在一个架构中运行多个Sentinel进程，这些进程使用流言协议（gossip protocols）l来接收关于master节点是否故障的信息，并使用投票协议（vote protocols）来决定是否执行故障切换，以及选择使用哪一个slave节点提升为master。哨兵机制可以解决故障发生时master与slave的自动切换，但无法解决单机性能瓶颈。
- 每个哨兵（Sentinel）进程会定时向其他节点（Sentinel、Master、Slave）发送消息，当对方节点在指定配置时间内没有进行回应，则判定该节点故障，这个过程就是“主观认为宕机”（Subjective down）,简称sdown。每个节点判定sdown状态的结果可能相同或不同。
- 当同一个哨兵集群中的多个（超过集群节点数一半以上）sentinel进程判定Master节点发生sdown后，并通过 SENTINEL is master down-by-addr 命令进行信息同步交流后，最终判定Master节点发生故障，这个通常称之为“客观宕机”（Objectively down），简称odown。
- 当哨兵集群判定Master发生odown后，通过一定vote算法从其余正常的slave节点中选举出一台服务器提升为Master节点，然后自动修改相关配置，并开启故障转移（failover）
- 客户端初始连接配置，应该选择连接Sentinel节点集合，而不再是单独连接redis节点，并声明选择连接的redis主节点或集群名称（Master name）,Sentinel接收到客户端请求将会返回消息通知客户端Master节点和Slave节点信息，由客户端程序执行相应请求（Sentinel节点仅作为配置中心，而非proxy代理）。
- 哨兵集群节点个数应该要配置为 大于或等于3的奇数
二、Sentinel哨兵配置文件详解
# Example sentinel.conf # 哨兵sentinel实例运行的端口 默认26379 port 26379 # 哨兵sentinel的工作目录 dir /tmp # 哨兵sentinel监控的redis主节点的 ip port # master-name 可以自己命名的主节点名字 只能由字母A-z、数字0-9 、这三个字符".-_"组成。 # quorum 当这些quorum个数sentinel哨兵认为master主节点失联 那么这时 客观上认为主节点失联了 # sentinel monitor <master-name> <ip> <redis-port> <quorum> sentinel monitor mymaster 127.0.0.1 6379 2 # 当在Redis实例中开启了requirepass foobared 授权密码 这样所有连接Redis实例的客户端都要提供密码 # 设置哨兵sentinel 连接主从的密码 注意必须为主从设置一样的验证密码 # sentinel auth-pass <master-name> <password> sentinel auth-pass mymaster MySUPER--secret-0123passw0rd # 指定多少毫秒之后 主节点没有应答哨兵sentinel 此时 哨兵主观上认为主节点下线 默认30秒 # sentinel down-after-milliseconds <master-name> <milliseconds> sentinel down-after-milliseconds mymaster 30000 # 这个配置项指定了在发生failover主备切换时最多可以有多少个slave同时对新的master进行 同步， 这个数字越小，完成failover所需的时间就越长， 但是如果这个数字越大，就意味着越 多的slave因为replication而不可用。 可以通过将这个值设为 1 来保证每次只有一个slave 处于不能处理命令请求的状态。 # sentinel parallel-syncs <master-name> <numslaves> sentinel parallel-syncs mymaster 1 # 故障转移的超时时间 failover-timeout 可以用在以下这些方面： #1. 同一个sentinel对同一个master两次failover之间的间隔时间。 #2. 当一个slave从一个错误的master那里同步数据开始计算时间。直到slave被纠正为向正确的master那里同步数据时。 #3.当想要取消一个正在进行的failover所需要的时间。 #4.当进行failover时，配置所有slaves指向新的master所需的最大时间。不过，即使过了这个超时，slaves依然会被正确配置为指向master，但是就不按parallel-syncs所配置的规则来了 # 默认三分钟 # sentinel failover-timeout <master-name> <milliseconds> sentinel failover-timeout mymaster 180000 # SCRIPTS EXECUTION #配置当某一事件发生时所需要执行的脚本，可以通过脚本来通知管理员，例如当系统运行不正常时发邮件通知相关人员。 #对于脚本的运行结果有以下规则： #若脚本执行后返回1，那么该脚本稍后将会被再次执行，重复次数目前默认为10 #若脚本执行后返回2，或者比2更高的一个返回值，脚本将不会重复执行。 #如果脚本在执行过程中由于收到系统中断信号被终止了，则同返回值为1时的行为相同。 #一个脚本的最大执行时间为60s，如果超过这个时间，脚本将会被一个SIGKILL信号终止，之后重新执行。 #通知型脚本:当sentinel有任何警告级别的事件发生时（比如说redis实例的主观失效和客观失效等等），将会去调用这个脚本， 这时这个脚本应该通过邮件，SMS等方式去通知系统管理员关于系统不正常运行的信息。调用该脚本时，将传给脚本两个参数， 一个是事件的类型， 一个是事件的描述。 如果sentinel.conf配置文件中配置了这个脚本路径，那么必须保证这个脚本存在于这个路径，并且是可执行的，否则sentinel无法正常启动成功。 #通知脚本 # sentinel notification-script <master-name> <script-path> sentinel notification-script mymaster /var/redis/notify.sh # 客户端重新配置主节点参数脚本 # 当一个master由于failover而发生改变时，这个脚本将会被调用，通知相关的客户端关于master地址已经发生改变的信息。 # 以下参数将会在调用脚本时传给脚本: # <master-name> <role> <state> <from-ip> <from-port> <to-ip> <to-port> # 目前<state>总是“failover”, # <role>是“leader”或者“observer”中的一个。 # 参数 from-ip, from-port, to-ip, to-port是用来和旧的master和新的master(即旧的slave)通信的 # 这个脚本应该是通用的，能被多次调用，不是针对性的。 # sentinel client-reconfig-script <master-name> <script-path> sentinel client-reconfig-script mymaster /var/redis/reconfig.sh
三、Sentinel哨兵机制部署
1、哨兵机制主从架构准备
#master节点redis配置文件修改内容 [root@Redis-Ubuntu-1804-p20:~]# cat /app/redis/etc/redis_6380.conf | grep -e "^bind\|^masterauth\|^replicaof\|^requirepass" bind 0.0.0.0 masterauth redis requirepass redis [root@Redis-Ubuntu-1804-p20:~]# #slave节点redis配置文件修改内容 [root@Redis-Ubuntu-1804-p21:~]# cat /redis/etc/redis_6380.conf | grep -e "^bind\|^masterauth\|^replicaof\|^requirepass" cat: /redis/etc/redis_6380.conf: No such file or directory [root@Redis-Ubuntu-1804-p21:~]# cat /app/redis/etc/redis_6380.conf | grep -e "^bind\|^masterauth\|^replicaof\|^requirepass" bind 0.0.0.0 replicaof 10.0.0.20 6380 masterauth redis requirepass redis [root@Redis-Ubuntu-1804-p21:~]# [root@Redis-Ubuntu-1804-p22:~]# cat /redis/etc/redis_6380.conf | grep -e "^bind\|^masterauth\|^replicaof\|^requirepass" cat: /redis/etc/redis_6380.conf: No such file or directory [root@Redis-Ubuntu-1804-p22:~]# cat /app/redis/etc/redis_6380.conf | grep -e "^bind\|^masterauth\|^replicaof\|^requirepass" bind 0.0.0.0 replicaof 10.0.0.20 6380 masterauth redis requirepass redis [root@Redis-Ubuntu-1804-p22:~]#
2、修改配置启动sentinel
#在每个节点上创建sentinel配置文件
[root@Redis-Ubuntu-1804-p20:~]# cat > /app/redis/etc/sentinel.conf <<EOF port 26379 daemonize yes pidfile /app/redis/run/redis-sentinel.pid logfile "/app/redis/log/sentinel.log" dir /app/redis sentinel monitor mymaster 10.0.0.20 6380 2 sentinel auth-pass mymaster redis sentinel parallel-syncs mymaster 1 sentinel failover-timeout mymaster 180000 sentinel deny-scripts-reconfig yes EOF
#启动sentinel [root@Redis-Ubuntu-1804-p20:~]# redis-sentinel /app/redis/etc/sentinel.conf [root@Redis-Ubuntu-1804-p20:~]# ss -ntlp State Recv-Q Send-Q Local Address:Port Peer Address:Port LISTEN 0 511 0.0.0.0:26379 0.0.0.0:* users:(("redis-sentinel",pid=2702,fd=7)) LISTEN 0 511 0.0.0.0:6379 0.0.0.0:* users:(("redis-server",pid=851,fd=6)) LISTEN 0 511 0.0.0.0:6380 0.0.0.0:* users:(("redis-server",pid=2101,fd=6)) LISTEN 0 511 0.0.0.0:6381 0.0.0.0:* users:(("redis-server",pid=881,fd=6)) LISTEN 0 128 127.0.0.53%lo:53 0.0.0.0:* users:(("systemd-resolve",pid=801,fd=13)) LISTEN 0 128 0.0.0.0:22 0.0.0.0:* users:(("sshd",pid=885,fd=3)) LISTEN 0 128 127.0.0.1:6010 0.0.0.0:* users:(("sshd",pid=1467,fd=10)) LISTEN 0 511 [::]:26379 [::]:* users:(("redis-sentinel",pid=2702,fd=6)) LISTEN 0 128 [::]:22 [::]:* users:(("sshd",pid=885,fd=4)) LISTEN 0 128 [::1]:6010 [::]:* users:(("sshd",pid=1467,fd=9))
3、观察sentinel配置文件变化
##启动后对比配置文件变化 [root@Redis-Ubuntu-1804-p20:~]# cat /app/redis/etc/sentinel.conf port 26379 daemonize yes pidfile "/app/redis/run/redis-sentinel.pid" logfile "/app/redis/log/sentinel.log" dir "/app/redis" sentinel myid 4e21cfb28d765283301f98584961adc0d755ac21 ##每个sentinel节点的id都需确保不同 sentinel deny-scripts-reconfig yes sentinel monitor mymaster 10.0.0.20 6380 2 sentinel auth-pass mymaster redis sentinel config-epoch mymaster 0 # Generated by CONFIG REWRITE protected-mode no sentinel leader-epoch mymaster 0 sentinel known-replica mymaster 10.0.0.22 6380 sentinel known-replica mymaster 10.0.0.21 6380 sentinel known-sentinel mymaster 10.0.0.22 26379 f41684db3a063d4468b5023f57c62a7a5bb3130e sentinel known-sentinel mymaster 10.0.0.21 26379 49b72e4d02964472051d55fd2980dd598332ac9f sentinel current-epoch 0 [root@Redis-Ubuntu-1804-p21:~]# cat /app/redis/etc/sentinel.conf port 26379 daemonize yes pidfile "/app/redis/run/redis-sentinel.pid" logfile "/app/redis/log/sentinel.log" dir "/app/redis" sentinel myid 49b72e4d02964472051d55fd2980dd598332ac9f ##每个sentinel节点的id都需确保不同 sentinel deny-scripts-reconfig yes sentinel monitor mymaster 10.0.0.20 6380 2 sentinel auth-pass mymaster redis sentinel config-epoch mymaster 0 # Generated by CONFIG REWRITE protected-mode no sentinel leader-epoch mymaster 0 sentinel known-replica mymaster 10.0.0.22 6380 sentinel known-replica mymaster 10.0.0.21 6380 sentinel known-sentinel mymaster 10.0.0.20 26379 4e21cfb28d765283301f98584961adc0d755ac21 sentinel known-sentinel mymaster 10.0.0.22 26379 f41684db3a063d4468b5023f57c62a7a5bb3130e sentinel current-epoch 0 [root@Redis-Ubuntu-1804-p22:~]# cat /app/redis/etc/sentinel.conf port 26379 daemonize yes pidfile "/app/redis/run/redis-sentinel.pid" logfile "/app/redis/log/sentinel.log" dir "/app/redis" sentinel myid f41684db3a063d4468b5023f57c62a7a5bb3130e ##每个sentinel节点的id都需确保不同 sentinel deny-scripts-reconfig yes sentinel monitor mymaster 10.0.0.20 6380 2 sentinel auth-pass mymaster redis sentinel config-epoch mymaster 0 # Generated by CONFIG REWRITE protected-mode no sentinel leader-epoch mymaster 0 sentinel known-replica mymaster 10.0.0.21 6380 sentinel known-replica mymaster 10.0.0.22 6380 sentinel known-sentinel mymaster 10.0.0.21 26379 49b72e4d02964472051d55fd2980dd598332ac9f sentinel known-sentinel mymaster 10.0.0.20 26379 4e21cfb28d765283301f98584961adc0d755ac21 sentinel current-epoch 0
4、查看sentinel状态
[root@Redis-Ubuntu-1804-p20:~]# redis-cli -a redis -p 26379 --no-auth-warning 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=10.0.0.20:6380,slaves=2,sentinels=3 [root@Redis-Ubuntu-1804-p21:~]# redis-cli -a redis -p 26379 --no-auth-warning 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=10.0.0.20:6380,slaves=2,sentinels=3 [root@Redis-Ubuntu-1804-p22:~]# redis-cli -a redis -p 26379 --no-auth-warning 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=10.0.0.20:6380,slaves=2,sentinels=3
python 脚本连接sentinel进行数据写入
#!/usr/bin/python3 # -*- coding: UTF-8 -*- #******************************************************************** #Author: janzen #Date: 2023-04-18 #FileName： redis_sentinel_newData.py #Description： The python3 script #Copyright (C): 2023 All rights reserved #******************************************************************** import redis from redis.sentinel import Sentinel import sys,time key=sys.argv[1] value=sys.argv[2] num=1 redis_auth_pass='redis' mastername='mymaster' sentinel = Sentinel([ ('10.0.0.20',26379), ('10.0.0.21',26379), ('10.0.0.22',26379)], socket_timeout=0.5 ) while 1: time.sleep(0.5) try: master = sentinel.discover_master(mastername) slave = sentinel.discover_slaves=(mastername) print("Master:%s ; Slave:%s" % (master,slave)) master = sentinel.master_for(mastername,socket_timeout=0.5,password=redis_auth_pass,db=0) w_ret=master.set(key+str(num),value+str(num)) slave = sentinel.slave_for(mastername,socket_timeout=0.5,password=redis_auth_pass,db=0) r_ret=master.get(key) print("get data %s:%s" % (key+str(num),r_ret)) except Exception as err: print(err) continue num+=1
5、模拟故障观察结果
[root@Redis-Ubuntu-1804-p20:~]# systemctl stop redis_6380.service
三个节点日志
##10.0.0.20：26379
2702:X 18 Apr 2023 05:23:31.362 # +sdown master mymaster 10.0.0.20 6380
2702:X 18 Apr 2023 05:23:31.464 # +odown master mymaster 10.0.0.20 6380 #quorum 2/2
2702:X 18 Apr 2023 05:23:31.464 # +new-epoch 11
2702:X 18 Apr 2023 05:23:31.464 # +try-failover master mymaster 10.0.0.20 6380
2702:X 18 Apr 2023 05:23:31.465 # +vote-for-leader 4e21cfb28d765283301f98584961adc0d755ac21 11
2702:X 18 Apr 2023 05:23:31.477 # 49b72e4d02964472051d55fd2980dd598332ac9f voted for 4e21cfb28d765283301f98584961adc0d755ac21 11
2702:X 18 Apr 2023 05:23:31.477 # f41684db3a063d4468b5023f57c62a7a5bb3130e voted for 4e21cfb28d765283301f98584961adc0d755ac21 11
2702:X 18 Apr 2023 05:23:31.556 # +elected-leader master mymaster 10.0.0.20 6380
2702:X 18 Apr 2023 05:23:31.557 # +failover-state-select-slave master mymaster 10.0.0.20 6380
2702:X 18 Apr 2023 05:23:31.609 # +selected-slave slave 10.0.0.22:6380 10.0.0.22 6380 @ mymaster 10.0.0.20 6380
2702:X 18 Apr 2023 05:23:31.610 * +failover-state-send-slaveof-noone slave 10.0.0.22:6380 10.0.0.22 6380 @ mymaster 10.0.0.20 6380
2702:X 18 Apr 2023 05:23:31.711 * +failover-state-wait-promotion slave 10.0.0.22:6380 10.0.0.22 6380 @ mymaster 10.0.0.20 6380
2702:X 18 Apr 2023 05:23:32.236 # +promoted-slave slave 10.0.0.22:6380 10.0.0.22 6380 @ mymaster 10.0.0.20 6380
2702:X 18 Apr 2023 05:23:32.237 # +failover-state-reconf-slaves master mymaster 10.0.0.20 6380
2702:X 18 Apr 2023 05:23:32.289 * +slave-reconf-sent slave 10.0.0.21:6380 10.0.0.21 6380 @ mymaster 10.0.0.20 6380
2702:X 18 Apr 2023 05:23:32.499 * +slave-reconf-inprog slave 10.0.0.21:6380 10.0.0.21 6380 @ mymaster 10.0.0.20 6380
2702:X 18 Apr 2023 05:23:32.551 # -odown master mymaster 10.0.0.20 6380
2702:X 18 Apr 2023 05:23:33.516 * +slave-reconf-done slave 10.0.0.21:6380 10.0.0.21 6380 @ mymaster 10.0.0.20 6380
2702:X 18 Apr 2023 05:23:33.598 # +failover-end master mymaster 10.0.0.20 6380
2702:X 18 Apr 2023 05:23:33.598 # +switch-master mymaster 10.0.0.20 6380 10.0.0.22 6380
2702:X 18 Apr 2023 05:23:33.599 * +slave slave 10.0.0.21:6380 10.0.0.21 6380 @ mymaster 10.0.0.22 6380
2702:X 18 Apr 2023 05:23:33.599 * +slave slave 10.0.0.20:6380 10.0.0.20 6380 @ mymaster 10.0.0.22 6380
2702:X 18 Apr 2023 05:24:03.600 # +sdown slave 10.0.0.20:6380 10.0.0.20 6380 @ mymaster 10.0.0.22 6380
##10.0.0.21：26379
2553:X 18 Apr 2023 05:23:31.416 # +sdown master mymaster 10.0.0.20 6380
2553:X 18 Apr 2023 05:23:31.474 # +new-epoch 11
2553:X 18 Apr 2023 05:23:31.482 # +vote-for-leader 4e21cfb28d765283301f98584961adc0d755ac21 11
2553:X 18 Apr 2023 05:23:31.507 # +odown master mymaster 10.0.0.20 6380 #quorum 3/2
2553:X 18 Apr 2023 05:23:31.507 # Next failover delay: I will not start a failover before Tue Apr 18 05:29:32 2023
2553:X 18 Apr 2023 05:23:32.296 # +config-update-from sentinel 4e21cfb28d765283301f98584961adc0d755ac21 10.0.0.20 26379 @ mymaster 10.0.0.20 6380
2553:X 18 Apr 2023 05:23:32.297 # +switch-master mymaster 10.0.0.20 6380 10.0.0.22 6380
2553:X 18 Apr 2023 05:23:32.297 * +slave slave 10.0.0.21:6380 10.0.0.21 6380 @ mymaster 10.0.0.22 6380
2553:X 18 Apr 2023 05:23:32.297 * +slave slave 10.0.0.20:6380 10.0.0.20 6380 @ mymaster 10.0.0.22 6380
2553:X 18 Apr 2023 05:24:02.315 # +sdown slave 10.0.0.20:6380 10.0.0.20 6380 @ mymaster 10.0.0.22 6380
##10.0.0.22：26379
5545:X 18 Apr 2023 05:23:31.326 # +sdown master mymaster 10.0.0.20 6380
5545:X 18 Apr 2023 05:23:31.465 # +new-epoch 11
5545:X 18 Apr 2023 05:23:31.474 # +vote-for-leader 4e21cfb28d765283301f98584961adc0d755ac21 11
5545:X 18 Apr 2023 05:23:32.287 # +config-update-from sentinel 4e21cfb28d765283301f98584961adc0d755ac21 10.0.0.20 26379 @ mymaster 10.0.0.20 6380
5545:X 18 Apr 2023 05:23:32.288 # +switch-master mymaster 10.0.0.20 6380 10.0.0.22 6380
5545:X 18 Apr 2023 05:23:32.288 * +slave slave 10.0.0.21:6380 10.0.0.21 6380 @ mymaster 10.0.0.22 6380
5545:X 18 Apr 2023 05:23:32.288 * +slave slave 10.0.0.20:6380 10.0.0.20 6380 @ mymaster 10.0.0.22 6380
5545:X 18 Apr 2023 05:24:02.317 # +sdown slave 10.0.0.20:6380 10.0.0.20 6380 @ mymaster 10.0.0.22 6380
##写程序
Master:('10.0.0.20', 6380) ; Slave:mymaster
set data key_229:b'value_229'
Master:('10.0.0.20', 6380) ; Slave:mymaster
set data key_230:b'value_230'
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
Master:('10.0.0.20', 6380) ; Slave:mymaster
Error 111 connecting to 10.0.0.20:6380. Connection refused.
No master found for 'mymaster'
Master:('10.0.0.22', 6380) ; Slave:mymaster
set data key_231:b'value_231'
Master:('10.0.0.22', 6380) ; Slave:mymaster
set data key_232:b'value_232'
Master:('10.0.0.22', 6380) ; Slave:mymaster
set data key_233:b'value_233'
Master:('10.0.0.22', 6380) ; Slave:mymaster
set data key_234:b'value_234'
Master:('10.0.0.22', 6380) ; Slave:mymaster
set data key_235:b'value_235'
Master:('10.0.0.22', 6380) ; Slave:mymaster
set data key_236:b'value_236'
Master:('10.0.0.22', 6380) ; Slave:mymaster
set data key_237:b'value_237'
Master:('10.0.0.22', 6380) ; Slave:mymaster
set data key_238:b'value_238'
##读程序
Master:('10.0.0.20', 6380) ; Slave:mymaster
get data key1:b'value1'
Master:('10.0.0.20', 6380) ; Slave:mymaster
get data key1:b'value1'
Master:('10.0.0.20', 6380) ; Slave:mymaster
get data key1:b'value1'
Master:('10.0.0.20', 6380) ; Slave:mymaster
get data key1:b'value1'
Master:('10.0.0.20', 6380) ; Slave:mymaster
get data key1:b'value1'
Master:('10.0.0.20', 6380) ; Slave:mymaster
get data key1:b'value1'
No master found for 'mymaster'
No master found for 'mymaster'
Master:('10.0.0.22', 6380) ; Slave:mymaster
get data key1:b'value1'
Master:('10.0.0.22', 6380) ; Slave:mymaster
get data key1:b'value1'
Master:('10.0.0.22', 6380) ; Slave:mymaster
get data key1:b'value1'
Master:('10.0.0.22', 6380) ; Slave:mymaster
get data key1:b'value1'
Master:('10.0.0.22', 6380) ; Slave:mymaster
get data key1:b'value1'
Master:('10.0.0.22', 6380) ; Slave:mymaster
get data key1:b'value1'
四、sentinel 运维
五、客户端连接Sentinel
1、客户端连接Sentinel工作原理
1、选举Sentinel
2、Sentinel通过MasterName获取Master节点信息
3、Sentinel发送Role指令确认Master节点信息
4、客户端订阅Sentinel频道，获取新的Master信息，并自动切换连接到新的Master
1.1、选举Sentinel
1.2、Sentinel通过MasterName获取Master节点信息
1.3、Sentinel发送Role指令确认Master节点信息
1.4、客户端订阅Sentinel频道，获取新的Master信息，并自动切换连接到新的Master
2、python连接Sentinel
[root@Client-Ubuntu-1804-250:~]# apt install python3 python3-redis -y
[root@Client-Ubuntu-1804-250:~]# cat script/redis/redis_sentinel_newData.py #!/usr/bin/python3 # -*- coding: UTF-8 -*- #******************************************************************** #Author: janzen #Date: 2023-04-18 #FileName： redis_sentinel_newData.py #Description： The python3 script #Copyright (C): 2023 All rights reserved #******************************************************************** import redis from redis.sentinel import Sentinel import sys,time key=sys.argv[1] value=sys.argv[2] num=1 redis_auth_pass='redis' mastername='mymaster' sentinel = Sentinel([ ('10.0.0.20',26379), ('10.0.0.21',26379), ('10.0.0.22',26379)], socket_timeout=0.5 ) while 1: time.sleep(1) try: master = sentinel.discover_master(mastername) slave = sentinel.discover_slave=(mastername) print("Master:%s ; Slave:%s" % (master,slave)) master = sentinel.master_for(mastername,socket_timeout=0.5,password=redis_auth_pass,db=0) w_ret=master.set(key+str(num),value+str(num)) slave = sentinel.slave_for(mastername,socket_timeout=0.5,password=redis_auth_pass,db=0) r_ret=master.get(key+str(num)) print("set data %s:%s" % (key+str(num),r_ret)) except Exception as err: print(err) continue num+=1
浙公网安备 33010602011771号