Redis主从集群搭建及容灾部署(哨兵sentinel)

redis容灾部署(哨兵Sentinel)

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    1、sentinel介绍

   Redis Sentinel 

   Sentinel(哨兵)是用于监控redis集群中Master状态的工具,其已经被集成在redis2.4+的版本中

    2、Sentinel作用: 

1):Master状态检测 

2):如果Master异常,则会进行Master-Slave切换,将其中一个Slave作为Master,将之前的Master作为Slave 

3):Master-Slave切换后,master_redis.conf、slave_redis.conf和sentinel.conf的内容都会发生改变,即master_redis.conf中会多一行slaveof的配置,sentinel.conf的监控目标会随之调换 

3、Sentinel工作方式: 

1):每个Sentinel以每秒钟一次的频率向它所知的Master,Slave以及其他 Sentinel 实例发送一个 PING 命令 

2):如果一个实例(instance)距离最后一次有效回复 PING 命令的时间超过 down-after-milliseconds 选项所指定的值, 则这个实例会被 Sentinel 标记为主观下线。 

3):如果一个Master被标记为主观下线,则正在监视这个Master的所有 Sentinel 要以每秒一次的频率确认Master的确进入了主观下线状态。 

4):当有足够数量的 Sentinel(大于等于配置文件指定的值)在指定的时间范围内确认Master的确进入了主观下线状态, 则Master会被标记为客观下线 

5):在一般情况下, 每个 Sentinel 会以每 10 秒一次的频率向它已知的所有Master,Slave发送 INFO 命令 

6):当Master被 Sentinel 标记为客观下线时,Sentinel 向下线的 Master 的所有 Slave 发送 INFO 命令的频率会从 10 秒一次改为每秒一次 

7):若没有足够数量的 Sentinel 同意 Master 已经下线, Master 的客观下线状态就会被移除。 

若 Master 重新向 Sentinel 的 PING 命令返回有效回复, Master 的主观下线状态就会被移除。

4、主观下线和客观下线 

主观下线:Subjectively Down,简称 SDOWN,指的是当前 Sentinel 实例对某个redis服务器做出的下线判断。 

客观下线:Objectively Down, 简称 ODOWN,指的是多个 Sentinel 实例在对Master Server做出 SDOWN 判断,并且通过 SENTINEL is-master-down-by-addr 命令互相交流之后,得出的Master Server下线判断,然后开启failover.

通俗来讲就是: 

redis的sentinel系统用来管理多个redis服务器,可以实现一个功能上实现HA的集群。该系统主要执行三个任务: 

1、监控( Monitoring ): Redis Sentinel实时监控主服务器和从服务器运行状态。 

2、提醒(notification): 当被监控的某个 Redis 服务器出现问题时, Redis Sentinel 可以向系统管理员发送通知, 也可以通过 API 向其他程序发送通知 

3. 故障迁移(failover发):自动主从切换

   4. 统一的配置管理:连接者询问sentinel取得主从的地址

   

    5、Raft分布式算法

1. 主要用途:用于分布式系统,系统容错,以及选出领头羊

2. 作者:Diego Ongaro,毕业于哈佛

3. 目前用到这个算法的项目有:

a. CoreOS : 见下面

b. ectd : a distributed, consistent shared configuration 

c. LogCabin : 分布式存储系统

d. redis sentinel : redis 的监控系统

    

   Sentinel使用的Raft算法核心: 原则

1. 所有sentinel都有选举的领头羊的权利

2. 每个sentinel都会要求其他sentinel选举自己为领头羊(主要由发现redis客观下线的sentinel先发起选举)

3. 每个sentinel只有一次选举的机会

4. 采用先到先得的原则

5. 一旦加入到系统了,则不会自动清除(这一点很重要, why?)

6. 每个sentinel都有唯一的uid,不会因为重启而变更

7. 达到领头羊的条件是 N/2 + 1个sentinel选择了自己

8. 采用配置纪元,如果一次选举出现脑裂,则配置纪元会递增,进入下一次选举,所有sentinel都会处于统一配置纪元,以最新的为标准。

Raft算法核心: 可视图

   Raft Visualization (算法演示)

   

   Raft分布式算法的应用

   coreos:云计算新星 Docker 正在以火箭般的速度发展,与它相关的生态圈也渐入佳境,CoreOS 就是其中之一。CoreOS 是一个全新的、面向数据中心设计的 Linux 操作系统,在2014年7月发布了首个稳定版本,目前已经完成了800万美元的A轮融资。

    一个简单的主从结构加sentinel集群的架构图如下: 

              192.168.110.134(master redis,sentinel)----------->192.168.110.135(slave redis,sentinel)

                        |                   \          /            |

                        |                    \        /             |

                        |                     \      /              |

                        |                      \    /               |

                        |                       \  /                |

                        |                        \                  |

                        |                         \                 |

                        |                       /  \                |

                        |                      /    \               |

                        |                     /      \              |

                        |                    /        \             |           

                    192.168.110.132(sentinel)----------->192.168.110.133(slave redis,sentinel)

      上图是一主一从节点,加上两个部署了sentinel的集群,sentinel集群之间会互相通信,沟通交流redis节点的状态,做出相应的判断并进行处理,这里的主观下线状态和客观下线状态是比较重要的状态,它们决定了是否进行故障转移。 

      

      可以 通过订阅指定的频道信息,当服务器出现故障得时候通知管理员 客户端可以将 Sentinel 看作是一个只提供了订阅功能的 Redis 服务

      器,你不可以使用 PUBLISH 命令向这个服务器发送信息,但你可以用 SUBSCRIBE 命令或者 PSUBSCRIBE 命令, 通过订阅给定的频道来获取

      相应的事件提醒。        

     6、配置哨兵

       

       1)、配置一个哨兵Sentinel的模式:

       把源码中的sentinel.conf配置文件拷贝到指定目录

       [root@web1 ~]# mkdir /usr/local/sentinel

       [root@web1 ~]# cd /usr/local/src/redis-3.2.6/

       [root@web1 redis-3.2.6]# cp sentinel.conf /usr/local/sentinel/

       [root@web1 redis-3.2.6]# cd /usr/local/sentinel/

       [root@web1 sentinel]# vim sentinel.conf 

[root@web1 sentinel]# grep -v "^#" sentinel.conf |grep -v "^$"

port 26379

dir /tmp

sentinel monitor mymaster 192.168.110.134 6379 1

sentinel down-after-milliseconds mymaster 30000

sentinel parallel-syncs mymaster 1

sentinel failover-timeout mymaster 180000

        

        例子:

        #sentinel端口

port 26380

#工作路径

dir "/usr/local/redis-6380"

# 守护进程模式

daemonize yes

# 指明日志文件名

logfile "./sentinel.log"

#哨兵监控的master,主从配置一样,在进行主从切换时6379会变成当前的master端口,

sentinel monitor mymaster 192.168.137.40 6379 1

# master或slave多长时间(默认30秒)不能使用后标记为s_down状态。

sentinel down-after-milliseconds mymaster 5000

#若sentinel在该配置值内未能完成failover操作(即故障时master/slave自动切换),则认为本次failover失败。

sentinel failover-timeout mymaster 18000

#设置master和slaves验证密码

sentinel auth-pass mymaster 123456

#哨兵程序自动添加的部分

# Generated by CONFIG REWRITE

sentinel config-epoch mymaster 0

sentinel leader-epoch mymaster 1

###指明了当前群集的从库的ip和端口,在主从切换时该值会改变

sentinel known-slave mymaster 192.168.137.40 6380

###除了当前的哨兵还有哪些监控的哨兵

sentinel known-sentinel mymaster 192.168.137.40 26379 7a88891a6147e202a53601ca16a3d438e9d55c9d

sentinel current-epoch 1

主要是这一项:

sentinel monitor mymaster 192.168.110.134 6379 2

my mymaster 后跟的是master的ip和端口

最后一个’2’代表我要启动只要有2个sentinel认为master下线,就认为该master客观下线,启动failover并选举产生新的master。

通常最后一个参数不能多于启动的sentinel实例数。

         

        [root@web2 ~]# mkdir /usr/local/sentinel

[root@web2 ~]# cp /usr/local/src/redis-3.2.6/sentinel.conf /usr/local/sentinel/

[root@web2 ~]# cd /usr/local/sentinel/

[root@web2 sentinel]# vim sentinel.conf 

[root@web2 sentinel]# grep -v "^#" sentinel.conf |grep -v "^$"

port 26379

dir /tmp

sentinel monitor mymaster 192.168.110.134 6379 2

sentinel down-after-milliseconds mymaster 30000

sentinel parallel-syncs mymaster 1

sentinel failover-timeout mymaster 180000

以后台启动模式启动两个sentinel(哨兵):

[root@web1 sentinel]# redis-sentinel /usr/local/sentinel/sentinel.conf &

[1] 18378

[root@web1 sentinel]# 18378:X 16 Dec 15:46:16.732 * Increased maximum number of open files to 10032 (it was originally set to 1024).

                _._                                                  

           _.-``__ ''-._                                             

      _.-``    `.  `_.  ''-._           Redis 3.2.6 (00000000/0) 64 bit

  .-`` .-```.  ```\/    _.,_ ''-._                                   

 (    '      ,       .-`  | `,    )     Running in sentinel mode

 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 26379

 |    `-._   `._    /     _.-'    |     PID: 18378

  `-._    `-._  `-./  _.-'    _.-'                                   

 |`-._`-._    `-.__.-'    _.-'_.-'|                                  

 |    `-._`-._        _.-'_.-'    |           http://redis.io        

  `-._    `-._`-.__.-'_.-'    _.-'                                   

 |`-._`-._    `-.__.-'    _.-'_.-'|                                  

 |    `-._`-._        _.-'_.-'    |                                  

  `-._    `-._`-.__.-'_.-'    _.-'                                   

      `-._    `-.__.-'    _.-'                                       

          `-._        _.-'                                           

              `-.__.-'                                               

18378:X 16 Dec 15:46:16.734 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.

18378:X 16 Dec 15:46:16.734 # Sentinel ID is 28c5f96738e4fe3335088d037a85ef47dfe9ab8f

18378:X 16 Dec 15:46:16.734 # +monitor master mymaster 192.168.110.134 6379 quorum 1

               

由上图可以看到:

1、 哨兵已经启动,它的id为236f14b361fc5a0dc0621cf88823ed6e6252b2f3

2、 为master数据库添加了一个监控

3、 发现了2个slave(由此可以看出,哨兵无需配置slave,只需要指定master,哨兵会自动发现slave)

    

   [root@web1 sentinel]# ps aux|grep redis

root     18357  0.1  1.0 135572  2440 ?        Ssl  15:40   0:00 redis-server *:6379                         

root     18378  0.1  1.0 133528  2572 pts/1    Sl   15:46   0:00 redis-sentinel *:26379 [sentinel]               

root     18400  0.0  0.3 103244   864 pts/1    S+   15:51   0:00 grep redis

    6、从Redis宕机测试

        

        把其中一个从redis 的进程 kill掉:

        [[root@web1 sentinel]# kill 18357

[root@web1 sentinel]# ps aux|grep redis

root     18378  0.1  1.0 133528  2572 pts/1    Sl   15:46   0:01 redis-sentinel *:26379 [sentinel]               

root     18444  0.0  0.3 103244   864 pts/1    S+   16:00   0:00 grep redis

        

        30秒后哨兵的控制台输出:

[root@web1 sentinel]# 18378:X 16 Dec 16:01:16.452 # +sdown master mymaster 192.168.110.134 6379

18378:X 16 Dec 16:01:16.452 # +odown master mymaster 192.168.110.134 6379 #quorum 1/1

18378:X 16 Dec 16:01:16.452 # +new-epoch 9

18378:X 16 Dec 16:01:16.452 # +try-failover master mymaster 192.168.110.134 6379

18378:X 16 Dec 16:01:16.470 # +vote-for-leader 28c5f96738e4fe3335088d037a85ef47dfe9ab8f 9

18378:X 16 Dec 16:01:16.470 # +elected-leader master mymaster 192.168.110.134 6379

18378:X 16 Dec 16:01:16.470 # +failover-state-select-slave master mymaster 192.168.110.134 6379

18378:X 16 Dec 16:01:16.546 # +selected-slave slave 192.168.110.135:6379 192.168.110.135 6379 @ mymaster 192.168.110.134 6379

18378:X 16 Dec 16:01:16.546 * +failover-state-send-slaveof-noone slave 192.168.110.135:6379 192.168.110.135 6379 @ mymaster 192.168.110.134 6379

18378:X 16 Dec 16:01:16.605 * +failover-state-wait-promotion slave 192.168.110.135:6379 192.168.110.135 6379 @ mymaster 192.168.110.134 6379

18378:X 16 Dec 16:01:16.699 # +promoted-slave slave 192.168.110.135:6379 192.168.110.135 6379 @ mymaster 192.168.110.134 6379

18378:X 16 Dec 16:01:16.699 # +failover-state-reconf-slaves master mymaster 192.168.110.134 6379

18378:X 16 Dec 16:01:16.759 # +failover-end master mymaster 192.168.110.134 6379

18378:X 16 Dec 16:01:16.759 # +switch-master mymaster 192.168.110.134 6379 192.168.110.135 6379

18378:X 16 Dec 16:01:16.760 * +slave slave 192.168.110.134:6379 192.168.110.134 6379 @ mymaster 192.168.110.135 6379

18378:X 16 Dec 16:01:46.858 # +sdown slave 192.168.110.134:6379 192.168.110.134 6379 @ mymaster 192.168.110.135 6379

30秒后哨兵的控制台输出:

18378:X 16 Dec 16:01:16.759 # +switch-master mymaster 192.168.110.134 6379 192.168.110.135 6379

   18378:X 16 Dec 16:01:16.760 * +slave slave 192.168.110.134:6379 192.168.110.134 6379 @ mymaster 192.168.110.135 6379

   18378:X 16 Dec 16:01:46.858 # +sdown slave 192.168.110.134:6379 192.168.110.134 6379 @ mymaster 192.168.110.135 6379

说明已经监控到刚才我人kill掉的master宕机了

        可以看出,slave重新已经转换成立主库 -sdown:说明是恢复服务。

        

        [root@web2 sentinel]# redis-cli 

127.0.0.1:6379> info replication

# Replication

role:master

connected_slaves:0

master_repl_offset:0

repl_backlog_active:0

repl_backlog_size:1048576

repl_backlog_first_byte_offset:0

repl_backlog_histlen:0

127.0.0.1:6379> 

         

         把192.168.110.134恢复:

         [root@web1 sentinel]# redis-server /usr/local/redis/etc/redis.conf 

[root@web1 sentinel]# 18378:X 16 Dec 16:06:59.825 # -sdown slave 192.168.110.134:6379 192.168.110.134 6379 @ mymaster 192.168.110.135 6379

18378:X 16 Dec 16:07:09.806 * +convert-to-slave slave 192.168.110.134:6379 192.168.110.134 6379 @ mymaster 192.168.110.135 6379

[root@web1 sentinel]# 

[root@web1 sentinel]# 

[root@web1 sentinel]# ps aux|grep redis

root     18378  0.2  1.0 133528  2636 pts/1    Sl   15:46   0:02 redis-sentinel *:26379 [sentinel]               

root     18487  0.1  1.0 135572  2564 ?        Ssl  16:06   0:00 redis-server *:6379                         

root     18491  0.0  0.3 103244   864 pts/1    S+   16:08   0:00 grep redis

         

         192.168.110.134是作为从库加入到复制中的(主库不会切换过来):

 

测试下:

[root@web2 sentinel]# redis-cli 

127.0.0.1:6379> info replication

# Replication

role:master

connected_slaves:1

slave0:ip=192.168.110.134,port=6379,state=online,offset=2835,lag=1

master_repl_offset:2835

repl_backlog_active:1

repl_backlog_size:1048576

repl_backlog_first_byte_offset:2

repl_backlog_histlen:2834

127.0.0.1:6379> info replication

# Replication

role:master

connected_slaves:1

slave0:ip=192.168.110.134,port=6379,state=online,offset=9687,lag=0

master_repl_offset:9832

repl_backlog_active:1

repl_backlog_size:1048576

repl_backlog_first_byte_offset:2

repl_backlog_histlen:9831

127.0.0.1:6379> info replication

# Replication

role:master

connected_slaves:1

slave0:ip=192.168.110.134,port=6379,state=online,offset=36450,lag=0

master_repl_offset:36595

repl_backlog_active:1

repl_backlog_size:1048576

repl_backlog_first_byte_offset:2

repl_backlog_histlen:36594

127.0.0.1:6379> set name2 lisi

OK

127.0.0.1:6379> set age2 22

OK

127.0.0.1:6379> get name2

"lisi"

127.0.0.1:6379> get age2

"22"

127.0.0.1:6379> 

[root@web1 sentinel]# redis-cli 

127.0.0.1:6379> info replication

# Replication

role:slave

master_host:192.168.110.135

master_port:6379

master_link_status:up

master_last_io_seconds_ago:0

master_sync_in_progress:0

slave_repl_offset:73863

slave_priority:100

slave_read_only:1

connected_slaves:0

master_repl_offset:0

repl_backlog_active:0

repl_backlog_size:1048576

repl_backlog_first_byte_offset:0

repl_backlog_histlen:0

127.0.0.1:6379> get name2

"lisi"

127.0.0.1:6379> get set2

(nil)

127.0.0.1:6379> get age2

"22"

127.0.0.1:6379> 

          效果不错:

          把主库切换回192.168.110.134

          [root@web2 sentinel]# ps aux|grep redis

root      7063  0.1  1.2 135572  3116 ?        Ssl  14:35   0:13 redis-server *:6379         

root      7649  0.0  0.3 103244   864 pts/1    S+   16:48   0:00 grep redis

 [root@web2 sentinel]# kill 7063

 [root@web1 sentinel]# 18522:X 16 Dec 16:49:05.725 # +sdown master mymaster 192.168.110.135 6379

18522:X 16 Dec 16:49:05.725 # +odown master mymaster 192.168.110.135 6379 #quorum 1/1

18522:X 16 Dec 16:49:05.725 # +new-epoch 10

18522:X 16 Dec 16:49:05.725 # +try-failover master mymaster 192.168.110.135 6379

18522:X 16 Dec 16:49:05.736 # +vote-for-leader 28c5f96738e4fe3335088d037a85ef47dfe9ab8f 10

18522:X 16 Dec 16:49:05.736 # +elected-leader master mymaster 192.168.110.135 6379

18522:X 16 Dec 16:49:05.736 # +failover-state-select-slave master mymaster 192.168.110.135 6379

18522:X 16 Dec 16:49:05.791 # +selected-slave slave 192.168.110.134:6379 192.168.110.134 6379 @ mymaster 192.168.110.135 6379

18522:X 16 Dec 16:49:05.791 * +failover-state-send-slaveof-noone slave 192.168.110.134:6379 192.168.110.134 6379 @ mymaster 192.168.110.135 6379

18522:X 16 Dec 16:49:05.875 * +failover-state-wait-promotion slave 192.168.110.134:6379 192.168.110.134 6379 @ mymaster 192.168.110.135 6379

18522:X 16 Dec 16:49:06.233 # +promoted-slave slave 192.168.110.134:6379 192.168.110.134 6379 @ mymaster 192.168.110.135 6379

18522:X 16 Dec 16:49:06.233 # +failover-state-reconf-slaves master mymaster 192.168.110.135 6379

18522:X 16 Dec 16:49:06.331 # +failover-end master mymaster 192.168.110.135 6379

18522:X 16 Dec 16:49:06.331 # +switch-master mymaster 192.168.110.135 6379 192.168.110.134 6379

18522:X 16 Dec 16:49:06.331 * +slave slave 192.168.110.135:6379 192.168.110.135 6379 @ mymaster 192.168.110.134 6379

18522:X 16 Dec 16:49:36.394 # +sdown slave 192.168.110.135:6379 192.168.110.135 6379 @ mymaster 192.168.110.134 6379

切换成功

[root@web1 sentinel]# redis-cli 

127.0.0.1:6379> info replication

# Replication

role:master

connected_slaves:0

master_repl_offset:0

repl_backlog_active:0

repl_backlog_size:1048576

repl_backlog_first_byte_offset:0

repl_backlog_histlen:0

127.0.0.1:6379> 

恢复192.168.110.135的redis:

[root@web2 sentinel]# redis-server /etc/redis.conf

127.0.0.1:6379> 18522:X 16 Dec 16:52:32.351 # -sdown slave 192.168.110.135:6379 192.168.110.135 6379 @ mymaster 192.168.110.134 6379

18522:X 16 Dec 16:52:42.305 * +convert-to-slave slave 192.168.110.135:6379 192.168.110.135 6379 @ mymaster 192.168.110.134 6379

        

        127.0.0.1:6379> 

127.0.0.1:6379> info replication

# Replication

role:master

connected_slaves:1

slave0:ip=192.168.110.135,port=6379,state=online,offset=13653,lag=1

master_repl_offset:13667

repl_backlog_active:1

repl_backlog_size:1048576

repl_backlog_first_byte_offset:2

repl_backlog_histlen:13666

127.0.0.1:6379> 

                                                                                                                                    1

        [root@web2 sentinel]# redis-cli 

127.0.0.1:6379> info replication

# Replication

role:slave

master_host:192.168.110.134

master_port:6379

master_link_status:up

master_last_io_seconds_ago:2

master_sync_in_progress:0

slave_repl_offset:16502

slave_priority:100

slave_read_only:1

connected_slaves:0

master_repl_offset:0

repl_backlog_active:0

repl_backlog_size:1048576

repl_backlog_first_byte_offset:0

repl_backlog_histlen:0

127.0.0.1:6379> 

     

     2)、配置两个哨兵Sentinel的模式: 

         [root@web1 sentinel]# grep -v "^$"  /usr/local/sentinel/sentinel.conf |grep -v "^#"

port 26379

dir "/tmp"

sentinel myid 28c5f96738e4fe3335088d037a85ef47dfe9ab8f

sentinel monitor mymaster 192.168.110.134 6379 2

sentinel config-epoch mymaster 10

sentinel leader-epoch mymaster 10

sentinel known-slave mymaster 192.168.110.135 6379

sentinel known-sentinel mymaster 192.168.110.135 26379 16286f52de2675345d1b11bc8946adc5d3f0c360

sentinel current-epoch 10

         [root@web2 sentinel]# grep -v "^$"  /usr/local/sentinel/sentinel.conf |grep -v "^#"

port 26379

dir "/tmp"

sentinel myid 16286f52de2675345d1b11bc8946adc5d3f0c360

sentinel monitor mymaster 192.168.110.134 6379 2

sentinel config-epoch mymaster 0

sentinel leader-epoch mymaster 6

sentinel known-slave mymaster 192.168.110.135 6379

sentinel known-sentinel mymaster 192.168.110.134 26379 28c5f96738e4fe3335088d037a85ef47dfe9ab8f

sentinel current-epoch 10

        

         主要是这一项:

         sentinel monitor mymaster 192.168.110.134 6379 2

         最后一个’2’代表我要启动只要有2个sentinel认为master下线,就认为该master客观下线,启动failover并选举产生新的master。

通常最后一个参数不能多于启动的sentinel实例数。

         

         [root@web1 sentinel]# redis-sentinel /usr/local/sentinel/sentinel.conf &

[1] 18747

[root@web1 sentinel]# 18747:X 16 Dec 17:04:30.597 * Increased maximum number of open files to 10032 (it was originally set to 1024).

                _._                                                  

           _.-``__ ''-._                                             

      _.-``    `.  `_.  ''-._           Redis 3.2.6 (00000000/0) 64 bit

  .-`` .-```.  ```\/    _.,_ ''-._                                   

 (    '      ,       .-`  | `,    )     Running in sentinel mode

 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 26379

 |    `-._   `._    /     _.-'    |     PID: 18747

  `-._    `-._  `-./  _.-'    _.-'                                   

 |`-._`-._    `-.__.-'    _.-'_.-'|                                  

 |    `-._`-._        _.-'_.-'    |           http://redis.io        

  `-._    `-._`-.__.-'_.-'    _.-'                                   

 |`-._`-._    `-.__.-'    _.-'_.-'|                                  

 |    `-._`-._        _.-'_.-'    |                                  

  `-._    `-._`-.__.-'_.-'    _.-'                                   

      `-._    `-.__.-'    _.-'                                       

          `-._        _.-'                                           

              `-.__.-'                                               

18747:X 16 Dec 17:04:30.599 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.

18747:X 16 Dec 17:04:30.599 # Sentinel ID is 28c5f96738e4fe3335088d037a85ef47dfe9ab8f

18747:X 16 Dec 17:04:30.599 # +monitor master mymaster 192.168.110.134 6379 quorum 2

18747:X 16 Dec 17:05:00.659 # +sdown sentinel 16286f52de2675345d1b11bc8946adc5d3f0c360 192.168.110.135 26379 @ mymaster 192.168.110.134 6379

[root@web2 sentinel]# redis-sentinel /usr/local/sentinel/sentinel.conf &

[1] 7726

You have new mail in /var/spool/mail/root

[root@web2 sentinel]# 7726:X 16 Dec 17:04:33.835 * Increased maximum number of open files to 10032 (it was originally set to 1024).

                _._                                                  

           _.-``__ ''-._                                             

      _.-``    `.  `_.  ''-._           Redis 3.2.6 (00000000/0) 64 bit

  .-`` .-```.  ```\/    _.,_ ''-._                                   

 (    '      ,       .-`  | `,    )     Running in sentinel mode

 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 26379

 |    `-._   `._    /     _.-'    |     PID: 7726

  `-._    `-._  `-./  _.-'    _.-'                                   

 |`-._`-._    `-.__.-'    _.-'_.-'|                                  

 |    `-._`-._        _.-'_.-'    |           http://redis.io        

  `-._    `-._`-.__.-'_.-'    _.-'                                   

 |`-._`-._    `-.__.-'    _.-'_.-'|                                  

 |    `-._`-._        _.-'_.-'    |                                  

  `-._    `-._`-.__.-'_.-'    _.-'                                   

      `-._    `-.__.-'    _.-'                                       

          `-._        _.-'                                           

              `-.__.-'                                               

7726:X 16 Dec 17:04:33.836 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.

7726:X 16 Dec 17:04:33.836 # Sentinel ID is 16286f52de2675345d1b11bc8946adc5d3f0c360

7726:X 16 Dec 17:04:33.836 # +monitor master mymaster 192.168.110.134 6379 quorum 2

7726:X 16 Dec 17:04:34.668 # +new-epoch 10

7726:X 16 Dec 17:05:03.836 # +sdown sentinel 28c5f96738e4fe3335088d037a85ef47dfe9ab8f 192.168.110.134 26379 @ mymaster 192.168.110.134 6379

   

   上面是有问题的:原因是bind 默认是仅仅监控本机和 192.168.1.1这两个IP地址

   # bind 127.0.0.1 192.168.1.1

   

   添加: bind 0.0.0.0

   就没问题了

   配置文件:

   [root@web1 ~]# grep -v "^$" /usr/local/sentinel/sentinel.conf |grep -v "^#"

bind 0.0.0.0

port 26379

dir "/tmp"

sentinel myid 28c5f96738e4fe3335088d037a85ef47dfe9ab8f

sentinel monitor mymaster 192.168.110.135 6379 2

sentinel config-epoch mymaster 14

sentinel leader-epoch mymaster 14

sentinel known-slave mymaster 192.168.110.134 6379

sentinel known-sentinel mymaster 192.168.110.135 26379 16286f52de2675345d1b11bc8946adc5d3f0c360

sentinel current-epoch 14

  

   主要是下面两项:

   bind 0.0.0.0

   sentinel monitor mymaster 192.168.110.135 6379 2

   

   如果设置了密码则添加下面一项:

   # sentinel auth-pass

   sentinel auth-pass def_master 012_345^678-90

   [root@web1 ~]# redis-sentinel /usr/local/sentinel/sentinel.conf &

[1] 1963

[root@web1 ~]# 1963:X 19 Dec 11:55:29.670 * Increased maximum number of open files to 10032 (it was originally set to 1024).

                _._                                                  

           _.-``__ ''-._                                             

      _.-``    `.  `_.  ''-._           Redis 3.2.6 (00000000/0) 64 bit

  .-`` .-```.  ```\/    _.,_ ''-._                                   

 (    '      ,       .-`  | `,    )     Running in sentinel mode

 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 26379

 |    `-._   `._    /     _.-'    |     PID: 1963

  `-._    `-._  `-./  _.-'    _.-'                                   

 |`-._`-._    `-.__.-'    _.-'_.-'|                                  

 |    `-._`-._        _.-'_.-'    |           http://redis.io        

  `-._    `-._`-.__.-'_.-'    _.-'                                   

 |`-._`-._    `-.__.-'    _.-'_.-'|                                  

 |    `-._`-._        _.-'_.-'    |                                  

  `-._    `-._`-.__.-'_.-'    _.-'                                   

      `-._    `-.__.-'    _.-'                                       

          `-._        _.-'                                           

              `-.__.-'                                               

1963:X 19 Dec 11:55:29.671 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.

1963:X 19 Dec 11:55:29.671 # Sentinel ID is 28c5f96738e4fe3335088d037a85ef47dfe9ab8f

1963:X 19 Dec 11:55:29.672 # +monitor master mymaster 192.168.110.134 6379 quorum 2

   上面表示启动没问题的:

   kill掉一个从redis,观察sentinel控制台输出信息:

   

[root@web1 ~]# kill 1912

[root@web1 ~]# ps aux|grep redis

root      1963  0.2  1.0 133528  2588 pts/0    Sl   11:55   0:00 redis-sentinel 0.0.0.0:26379 [sentinel]         

root      1992  0.0  0.3 103244   864 pts/0    S+   11:58   0:00 grep redis

[root@web1 ~]# 1963:X 19 Dec 11:59:06.906 # +sdown master mymaster 192.168.110.134 6379

1963:X 19 Dec 11:59:06.963 # +odown master mymaster 192.168.110.134 6379 #quorum 2/2

1963:X 19 Dec 11:59:06.963 # +new-epoch 14

1963:X 19 Dec 11:59:06.963 # +try-failover master mymaster 192.168.110.134 6379

1963:X 19 Dec 11:59:06.972 # +vote-for-leader 28c5f96738e4fe3335088d037a85ef47dfe9ab8f 14

1963:X 19 Dec 11:59:06.992 # 16286f52de2675345d1b11bc8946adc5d3f0c360 voted for 28c5f96738e4fe3335088d037a85ef47dfe9ab8f 14

1963:X 19 Dec 11:59:07.035 # +elected-leader master mymaster 192.168.110.134 6379

1963:X 19 Dec 11:59:07.035 # +failover-state-select-slave master mymaster 192.168.110.134 6379

1963:X 19 Dec 11:59:07.136 # +selected-slave slave 192.168.110.135:6379 192.168.110.135 6379 @ mymaster 192.168.110.134 6379

1963:X 19 Dec 11:59:07.136 * +failover-state-send-slaveof-noone slave 192.168.110.135:6379 192.168.110.135 6379 @ mymaster 192.168.110.134 6379

1963:X 19 Dec 11:59:07.199 * +failover-state-wait-promotion slave 192.168.110.135:6379 192.168.110.135 6379 @ mymaster 192.168.110.134 6379

1963:X 19 Dec 11:59:08.171 # +promoted-slave slave 192.168.110.135:6379 192.168.110.135 6379 @ mymaster 192.168.110.134 6379

1963:X 19 Dec 11:59:08.171 # +failover-state-reconf-slaves master mymaster 192.168.110.134 6379

1963:X 19 Dec 11:59:08.260 # +failover-end master mymaster 192.168.110.134 6379

1963:X 19 Dec 11:59:08.260 # +switch-master mymaster 192.168.110.134 6379 192.168.110.135 6379

1963:X 19 Dec 11:59:08.260 * +slave slave 192.168.110.134:6379 192.168.110.134 6379 @ mymaster 192.168.110.135 6379

1963:X 19 Dec 11:59:38.290 # +sdown slave 192.168.110.134:6379 192.168.110.134 6379 @ mymaster 192.168.110.135 6379

另一台:

[root@web2 ~]# redis-sentinel /usr/local/sentinel/sentinel.conf &

[1] 1809

[root@web2 ~]# 1809:X 19 Dec 11:55:35.698 * Increased maximum number of open files to 10032 (it was originally set to 1024).

                _._                                                  

           _.-``__ ''-._                                             

      _.-``    `.  `_.  ''-._           Redis 3.2.6 (00000000/0) 64 bit

  .-`` .-```.  ```\/    _.,_ ''-._                                   

 (    '      ,       .-`  | `,    )     Running in sentinel mode

 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 26379

 |    `-._   `._    /     _.-'    |     PID: 1809

  `-._    `-._  `-./  _.-'    _.-'                                   

 |`-._`-._    `-.__.-'    _.-'_.-'|                                  

 |    `-._`-._        _.-'_.-'    |           http://redis.io        

  `-._    `-._`-.__.-'_.-'    _.-'                                   

 |`-._`-._    `-.__.-'    _.-'_.-'|                                  

 |    `-._`-._        _.-'_.-'    |                                  

  `-._    `-._`-.__.-'_.-'    _.-'                                   

      `-._    `-.__.-'    _.-'                                       

          `-._        _.-'                                           

              `-.__.-'                                               

1809:X 19 Dec 11:55:35.700 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.

1809:X 19 Dec 11:55:35.700 # Sentinel ID is 16286f52de2675345d1b11bc8946adc5d3f0c360

1809:X 19 Dec 11:55:35.700 # +monitor master mymaster 192.168.110.134 6379 quorum 2

1809:X 19 Dec 11:59:06.895 # +sdown master mymaster 192.168.110.134 6379

1809:X 19 Dec 11:59:06.999 # +new-epoch 14

1809:X 19 Dec 11:59:07.001 # +vote-for-leader 28c5f96738e4fe3335088d037a85ef47dfe9ab8f 14

1809:X 19 Dec 11:59:08.020 # +odown master mymaster 192.168.110.134 6379 #quorum 2/2

1809:X 19 Dec 11:59:08.020 # Next failover delay: I will not start a failover before Mon Dec 19 12:05:07 2016

1809:X 19 Dec 11:59:08.284 # +config-update-from sentinel 28c5f96738e4fe3335088d037a85ef47dfe9ab8f 192.168.110.134 26379 @ mymaster 192.168.110.134 6379

1809:X 19 Dec 11:59:08.284 # +switch-master mymaster 192.168.110.134 6379 192.168.110.135 6379

1809:X 19 Dec 11:59:08.284 * +slave slave 192.168.110.134:6379 192.168.110.134 6379 @ mymaster 192.168.110.135 6379

1809:X 19 Dec 11:59:38.344 # +sdown slave 192.168.110.134:6379 192.168.110.134 6379 @ mymaster 192.168.110.135 6379

[root@web2 ~]# redis-cli 

127.0.0.1:6379> info replication

# Replication

role:master

connected_slaves:0

master_repl_offset:0

repl_backlog_active:0

repl_backlog_size:1048576

repl_backlog_first_byte_offset:0

repl_backlog_histlen:0

127.0.0.1:6379> 

恢复192.168.110.134:

[root@web1 ~]# redis-server /usr/local/redis/etc/redis.conf 

[root@web1 ~]# 1963:X 19 Dec 12:14:24.393 # -sdown slave 192.168.110.134:6379 192.168.110.134 6379 @ mymaster 192.168.110.135 6379

[root@web1 ~]# redis-cli 

127.0.0.1:6379> info replication

# Replication

role:slave

master_host:192.168.110.135

master_port:6379

master_link_status:up

master_last_io_seconds_ago:1

master_sync_in_progress:0

slave_repl_offset:38769

slave_priority:100

slave_read_only:1

connected_slaves:0

master_repl_offset:0

repl_backlog_active:0

repl_backlog_size:1048576

repl_backlog_first_byte_offset:0

repl_backlog_histlen:0

127.0.0.1:6379> 

135上的显示:

repl_backlog_histlen:0

127.0.0.1:6379> 1809:X 19 Dec 12:14:24.105 # -sdown slave 192.168.110.134:6379 192.168.110.134 6379 @ mymaster 192.168.110.135 6379

127.0.0.1:6379> 

127.0.0.1:6379> info replication

# Replication

role:master

connected_slaves:1

slave0:ip=192.168.110.134,port=6379,state=online,offset=2404,lag=1

master_repl_offset:2404

repl_backlog_active:1

repl_backlog_size:1048576

repl_backlog_first_byte_offset:2

repl_backlog_histlen:2403

也是仅仅作为从。

         2)、配置三个哨兵Sentinel的模式:

            

            [root@web2 ~]# scp redis-3.2.6.tar.gz 192.168.110.133:/root

The authenticity of host '192.168.110.133 (192.168.110.133)' can't be established.

RSA key fingerprint is 60:6c:0d:f4:3b:f8:42:b1:c9:7e:ab:c4:bc:83:d1:09.

Are you sure you want to continue connecting (yes/no)? yes

Warning: Permanently added '192.168.110.133' (RSA) to the list of known hosts.

root@192.168.110.133's password: 

redis-3.2.6.tar.gz                                                                                 100% 1509KB   1.5MB/s   00:00

            [root@node2 ~]# iptables -I INPUT 6 -m state --state NEW -p tcp --dport 6379 -j ACCEPT

            [root@node2 ~]# iptables -I INPUT 7 -m state --state NEW -p tcp --dport 26379 -j ACCEPT

            [root@node2 ~]# tar -zxvf redis-3.2.6.tar.gz -C /usr/local/src/

            [root@node2 ~]# cd /usr/local/src/redis-3.2.6/

            [root@node2 redis-3.2.6]# make

            [root@node2 redis-3.2.6]# make install


文章标题:Redis主从集群搭建及容灾部署(哨兵sentinel)
URL地址:http://myzitong.com/article/jsoigo.html