02.Redis主从集群的Sentinel配置

1.Linux服务器列表
使用4台CentOS Linux服务器搭建环境，其IP地址如下：
192.168.110.100
192.168.110.101
192.168.110.102
192.168.110.103

　　

2.Redis服务部署环境
192.168.110.100
启动多个Redis sentinel服务，构成Redis sentinel集群
192.168.110.101
启动Redis服务，设置成主节点
192.168.110.102
启动Redis服务，设置成192.168.110.101的从节点
192.168.110.103
启动Redis服务，设置成192.168.110.101的从节点

2.配置并启动Redis主从集群

1.修改redis.conf配置文件
主节点的redis配置文件使用默认的配置文件就可以了，从节点的redis配置文件修改如下：
 
# Master-Slave replication. Use slaveof to make a Redis instance a copy of
# another Redis server. A few things to understand ASAP about Redis replication.
#
# 1) Redis replication is asynchronous, but you can configure a master to
#    stop accepting writes if it appears to be not connected with at least
#    a given number of slaves.
# 2) Redis slaves are able to perform a partial resynchronization with the
#    master if the replication link is lost for a relatively small amount of
#    time. You may want to configure the replication backlog size (see the next
#    sections of this file) with a sensible value depending on your needs.
# 3) Replication is automatic and does not need user intervention. After a
#    network partition slaves automatically try to reconnect to masters
#    and resynchronize with them.
#
# 主从同步。通过 slaveof 配置来实现Redis实例的备份。
# 注意，这里是本地从远端复制数据。也就是说，本地可以有不同的数据库文件、绑定不同的IP、监听不同的端口。
#
# slaveof <masterip> <masterport>
slaveof 192.168.110.101 6379

　　

注意:两台从节点都要改。
2.启动Redis主从集群
先启动192.168.110.101主节点，使用默认配置，脚本：
[lizhiwei@localhost bin]$ ./redis-server

　　

再启动192.168.110.102和192.168.110.103从节点，使用刚才的配置，脚本：
 
./redis-server redis.conf

　　

3.查看集群
192.168.110.101主节点Replication信息
[lizhiwei@localhost bin]$ ./redis-cli -h 192.168.110.101 info Replication
# Replication
role:master
connected_slaves:2
slave0:ip=192.168.110.102,port=6379,state=online,offset=659,lag=1
slave1:ip=192.168.110.103,port=6379,state=online,offset=659,lag=0
master_repl_offset:659
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:2
repl_backlog_histlen:658

　　

192.168.110.102从节点Replication信息
 
[lizhiwei@localhost bin]$ ./redis-cli -h 192.168.110.102 info Replication 
# Replication
role:slave
master_host:192.168.110.101
master_port:6379
master_link_status:up
master_last_io_seconds_ago:3
master_sync_in_progress:0
slave_repl_offset:701
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

　　

192.168.110.103从节点Replication信息
[lizhiwei@localhost bin]$ ./redis-cli -h 192.168.110.103 info Replication 
# Replication
role:slave
master_host:192.168.110.101
master_port:6379
master_link_status:up
master_last_io_seconds_ago:9
master_sync_in_progress:0
slave_repl_offset:715
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

　　

此时，存储到192.168.110.101主节点的数据，在从节点中都可以查询到。从节点会备份主节点的数据。

3.配置sentinel集群并启动

1.创建sentinel.conf配置文件
 
port 26379
# sentinel announce-ip <ip>
# sentinel announce-port <port>
dir /tmp
################################# master001 #################################
sentinel monitor master001 192.168.110.101 6379 2
# sentinel auth-pass <master-name> <password>
sentinel down-after-milliseconds master001 30000
sentinel parallel-syncs master001 1
sentinel failover-timeout master001 180000
# sentinel notification-script <master-name> <script-path>
# sentinel client-reconfig-script <master-name> <script-path>
# 可以配置多个master节点
################################# master002 #################################

　　

配置文件说明：
1. port :当前Sentinel服务运行的端口
 
2. dir : Sentinel服务运行时使用的临时文件夹
 
3.sentinel monitor master001 192.168.110.101 6379 2:Sentinel去监视一个名为master001的主redis实例，这个主实例的IP地址为本机地址192.168.110.101，端口号为6379，而将这个主实例判断为失效至少需要2个 Sentinel进程的同意，只要同意Sentinel的数量不达标，自动failover就不会执行
 
4.sentinel down-after-milliseconds master001 30000:指定了Sentinel认为Redis实例已经失效所需的毫秒数。当实例超过该时间没有返回PING，或者直接返回错误，那么Sentinel将这个实例标记为主观下线。只有一个 Sentinel进程将实例标记为主观下线并不一定会引起实例的自动故障迁移：只有在足够数量的Sentinel都将一个实例标记为主观下线之后，实例才会被标记为客观下线，这时自动故障迁移才会执行
 
5.sentinel parallel-syncs master001 1：指定了在执行故障转移时，最多可以有多少个从Redis实例在同步新的主实例，在从Redis实例较多的情况下这个数字越小，同步的时间越长，完成故障转移所需的时间就越长
 
6.sentinel failover-timeout master001 180000：如果在该时间（ms）内未能完成failover操作，则认为该failover失败
 
7.sentinel notification-script <master-name> <script-path>：指定sentinel检测到该监控的redis实例指向的实例异常时，调用的报警脚本。该配置项可选，但是很常用
2.启动sentinel集群
创建3个sentinel.conf配置文件：sentinel001.conf、sentinel002.conf、sentinel003.conf并修改端口号分别为：26379、36379、46379，并启动服务：
 
./redis-sentinel sentinel001.conf
./redis-sentinel sentinel002.conf
./redis-sentinel sentinel003.conf

　　

启动三个sentinel服务后会在其控制台看到如下信息：
./redis-sentinel sentinel001.conf，端口：26379
[7743] 01 Oct 06:20:38.162 # Sentinel runid is ba6c42e1accc31290e11d5876275e1562564295d
[7743] 01 Oct 06:20:38.162 # +monitor master master001 192.168.110.101 6379 quorum 2
[7743] 01 Oct 06:20:39.110 * +slave slave 192.168.110.102:6379 192.168.110.102 6379 @ master001 192.168.110.101 6379
[7743] 01 Oct 06:20:39.111 * +slave slave 192.168.110.103:6379 192.168.110.103 6379 @ master001 192.168.110.101 6379
[7743] 01 Oct 06:25:07.595 * +sentinel sentinel 192.168.110.100:36379 192.168.110.100 36379 @ master001 192.168.110.101 6379
[7743] 01 Oct 06:26:11.170 * +sentinel sentinel 192.168.110.100:46379 192.168.110.100 46379 @ master001 192.168.110.101 6379

　　

./redis-sentinel sentinel002.conf，端口：36379
[7795] 01 Oct 06:25:05.538 # Sentinel runid is 52c14768b15837fb601b26328acf150c6bd30682
[7795] 01 Oct 06:25:05.538 # +monitor master master001 192.168.110.101 6379 quorum 2
[7795] 01 Oct 06:25:06.505 * +slave slave 192.168.110.102:6379 192.168.110.102 6379 @ master001 192.168.110.101 6379
[7795] 01 Oct 06:25:06.515 * +slave slave 192.168.110.103:6379 192.168.110.103 6379 @ master001 192.168.110.101 6379
[7795] 01 Oct 06:25:07.557 * +sentinel sentinel 192.168.110.100:26379 192.168.110.100 26379 @ master001 192.168.110.101 6379
[7795] 01 Oct 06:26:11.168 * +sentinel sentinel 192.168.110.100:46379 192.168.110.100 46379 @ master001 192.168.110.101 6379

　　

./redis-sentinel sentinel003.conf，端口：46379
[7828] 01 Oct 06:26:09.076 # Sentinel runid is c8509594be4a36660b2122b3b81f4f74060c9b04
[7828] 01 Oct 06:26:09.076 # +monitor master master001 192.168.110.101 6379 quorum 2
[7828] 01 Oct 06:26:10.063 * +slave slave 192.168.110.102:6379 192.168.110.102 6379 @ master001 192.168.110.101 6379
[7828] 01 Oct 06:26:10.071 * +slave slave 192.168.110.103:6379 192.168.110.103 6379 @ master001 192.168.110.101 6379
[7828] 01 Oct 06:26:11.516 * +sentinel sentinel 192.168.110.100:26379 192.168.110.100 26379 @ master001 192.168.110.101 6379
[7828] 01 Oct 06:26:11.674 * +sentinel sentinel 192.168.110.100:36379 192.168.110.100 36379 @ master001 192.168.110.101 6379

　　

每个sentinel服务能知道其他所有的服务！

4.测试sentinel集群

1.停止192.168.110.101主节点
停止192.168.110.101Redis主节点后，在查看Replication信息如下：
[lizhiwei@localhost bin]$ ./redis-cli -h 192.168.110.101 info Replication          
Could not connect to Redis at 192.168.110.101:6379: Connection refused
[lizhiwei@localhost bin]$ ./redis-cli -h 192.168.110.102 info Replication 
# Replication
role:slave
master_host:192.168.110.103
master_port:6379
master_link_status:up
master_last_io_seconds_ago:1
master_sync_in_progress:0
slave_repl_offset:29128
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
[lizhiwei@localhost bin]$ ./redis-cli -h 192.168.110.103 info Replication 
# Replication
role:master
connected_slaves:1
slave0:ip=192.168.110.102,port=6379,state=online,offset=30456,lag=1
master_repl_offset:30456
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:2
repl_backlog_histlen:30455
[lizhiwei@localhost bin]$

　　

发现192.168.110.101Redis主节点已经不能连接，192.168.110.103成了主节点！
2.再启动192.168.110.101主节点
再启动192.168.110.101Redis主节点后，在查看Replication信息如下：
### 启动脚本，仍然使用默认配置
[lizhiwei@localhost bin]$ ./redis-server 
[lizhiwei@localhost bin]$ ./redis-cli -h 192.168.110.101 info Replication 
# Replication
role:slave
master_host:192.168.110.103
master_port:6379
master_link_status:up
master_last_io_seconds_ago:1
master_sync_in_progress:0
slave_repl_offset:57657
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

[lizhiwei@localhost bin]$ ./redis-cli -h 192.168.110.102 info Replication 
# Replication
role:slave
master_host:192.168.110.103
master_port:6379
master_link_status:up
master_last_io_seconds_ago:0
master_sync_in_progress:0
slave_repl_offset:60751
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

[lizhiwei@localhost bin]$ ./redis-cli -h 192.168.110.103 info Replication 
# Replication
role:master
connected_slaves:2
slave0:ip=192.168.110.102,port=6379,state=online,offset=63247,lag=1
slave1:ip=192.168.110.101,port=6379,state=online,offset=63247,lag=1
master_repl_offset:63393
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:2
repl_backlog_histlen:63392
[lizhiwei@localhost bin]$

　　

发现192.168.110.101节点启动后还再集群中，只不过成了从节点，192.168.110.103仍然是主节点，但是现在又有两个从节点了！
3.只留下一个sentinel服务，再停止192.168.110.103主节点，查看Redis集群是否出现新的主节点
停止sentinel服务，只留下一个sentinel服务，再停止Redis主节点，查看Replication信息如下：
[lizhiwei@localhost bin]$ ./redis-cli -h 192.168.110.101 info Replication 
# Replication
role:slave
master_host:192.168.110.103
master_port:6379
master_link_status:down
master_last_io_seconds_ago:-1
master_sync_in_progress:0
slave_repl_offset:184231
master_link_down_since_seconds:43
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
[lizhiwei@localhost bin]$ ./redis-cli -h 192.168.110.102 info Replication 
# Replication
role:slave
master_host:192.168.110.103
master_port:6379
master_link_status:down
master_last_io_seconds_ago:-1
master_sync_in_progress:0
slave_repl_offset:184231
master_link_down_since_seconds:52
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
[lizhiwei@localhost bin]$ ./redis-cli -h 192.168.110.103 info Replication 
Could not connect to Redis at 192.168.110.103:6379: Connection refused

　　

发现192.168.110.103主节点已经不能连接了，也不存在Redis主节点，集群中无主节点了！！！分析原因是：sentinel.conf配置的sentinel monitor master001 192.168.110.101 6379 2最后一个参数是2导致，若是但节点此配置的最后一个参数要使用是1。(此原因我已证实)
注意：在生产环境下建议sentinel节点的数量能在3个以上，并且最好不要在同一台机器上(使用同一网卡)。
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转自：http://www.cnblogs.com/LiZhiW/p/4851631.html

 

posted @ 2016-11-01 13:47  Mason.Ke  阅读(274)  评论(0)  编辑  收藏  举报