简单dockerfile文件，用于演示sentinel哨兵故障转移
FROM centos:latest
MAINTAINER BIXIAOYU
RUN groupadd -r redis &&useradd -r -g redis redis
RUN yum -y update && yum -y install epel-release && yum -y install redis && yum -y install net-tools
EXPOSE 6379
# docker build --no-cache -t redis .
启动docker容器实例
docker run -itd --name redis-master --net=mynetwork -p 6383:6379 --ip 172.60.0.3 redis
docker run -itd --name redis-slave1 --net=mynetwork -p 6384:6379 --ip 172.60.0.4 redis
docker run -itd --name redis-slave2 --net=mynetwork -p 6385:6379 --ip 172.60.0.5 redis
docker run -itd --name redis-sentinel1 --net=mynetwork -p : --ip 172.60.0.5 redis
docker run -itd --name redis-sentinel2 --net=mynetwork -p : --ip 172.60.0.6 redis
docker run -itd --name redis-sentinel3 --net=mynetwork -p : --ip 172.60.0.7 redis
#docker network create --subnet=172.60.0.0/16 mynetwork
【配置】
先完成主从同步，主从同步的配置可参考https://www.cnblogs.com/bixiaoyu/p/10706811.html这篇文章，在此就不必细说了，重点是sentinel的配置
bind 0.0.0.0 #设置允许访问的IP，这里仍然设置0.0.0.0
protected-mode no #允许在连接时，密码为空
port
dir "/tmp"
sentinel myid 6d0d4099c13cdeab018e1f2005455be6f1cd6f6b
sentinel monitor mymaster 172.60.0.3 2 #设置监听
sentinel config-epoch mymaster
sentinel leader-epoch mymaster
logfile "/var/log/redis/sentinel.log"
sentinel known-slave mymaster 172.60.0.2
sentinel known-slave mymaster 172.60.0.4
sentinel known-sentinel mymaster 172.60.0.7 dfce433e021aa3e82276974aa12fa0684fb0b4f0
sentinel known-sentinel mymaster 172.60.0.6 ceb363cf84103950cfa2a785816c4e8a36c02143
sentinel current-epoch
选择一个sentinel节点，查看日志信息，发现默认主节点为172.60.0.2
【测试故障转移】
先通过pkill模拟故障master故障宕机，随后观察哨兵任意节点的情况
我们可以从下面sentinel节点上看到172.0.0.3被选举成为新主节点
[root@ef77b61448fc /]# tail /var/log/redis/sentinel.log
:X Apr ::26.472 * +sentinel sentinel ceb363cf84103950cfa2a785816c4e8a36c02143 172.60.0.6 @ mymaster 172.60.0.2
:X Apr ::24.154 * +sentinel sentinel dfce433e021aa3e82276974aa12fa0684fb0b4f0 172.60.0.7 @ mymaster 172.60.0.2
:X Apr ::05.724 # +sdown master mymaster 172.60.0.2
:X Apr ::05.895 # +new-epoch
:X Apr ::05.895 # +vote-for-leader dfce433e021aa3e82276974aa12fa0684fb0b4f0
:X Apr ::06.276 # +config-update-from sentinel dfce433e021aa3e82276974aa12fa0684fb0b4f0 172.60.0.7 @ mymaster 172.60.0.2
:X Apr ::06.276 # +switch-master mymaster 172.60.0.2 172.60.0.3
:X Apr ::06.276 * +slave slave 172.60.0.4: 172.60.0.4 @ mymaster 172.60.0.3
:X Apr ::06.276 * +slave slave 172.60.0.2: 172.60.0.2 @ mymaster 172.60.0.3
查看sentinel节点的日志信息
此时，我们把pkill掉的172.60.0.2(旧主节点)重启，在看看新任Master主节点172.60.0.3有何变化
重启的旧主节点成为从节点并加入进来，此时正在进行复制动作，offset的偏移量还没有同步一致，
【小结】
进入哨兵节点客户端执行SENTINEL masterts命令显示被监控的所有master以及状态
127.0.0.1:> SENTINEL masters
) ) "name"
) "mymaster" #被监控主节点的名称
) "ip"
) "172.60.0.3" #被监控主节点的IP
) "port"
) ""
) "runid"
) "dd3696a2793e4e19892fca48793d75cec3f07bea" #被监控主节点的runid值
) "flags"
) "master"
) "link-pending-commands"
) ""
) "link-refcount"
) ""
) "last-ping-sent"
) ""
) "last-ok-ping-reply"
) ""
) "last-ping-reply"
) ""
) "down-after-milliseconds"
) "" #监控节点不可达超时时间
) "info-refresh"
) ""
) "role-reported"
) "master"
) "role-reported-time"
) ""
) "config-epoch"
) ""
) "num-slaves" #检测剩余slave节点个数
) ""
) "num-other-sentinels" #检测其它sentinel节点个数
) ""
) "quorum" #允许主节点不可用的sentinels的数量（最多允许两个sentinel节点故障）
) ""
) "failover-timeout" #延迟时间
) ""
) "parallel-syncs" #复制转移数量
) ""
执行SENTINEL slaves mymastert查看从节点信息，此时你会看到两个从节点
) ) "name"
) "172.60.0.2:6379"
) "ip"
) "172.60.0.2"
) "port"
) ""
) "runid"
) "3ede55439a3ce6fb1ab171ed7fd6b6c639725966"
) "flags"
) "slave"
) "link-pending-commands"
) ""
) "link-refcount"
) ""
) "last-ping-sent"
) ""
) "last-ok-ping-reply"
) ""
) "last-ping-reply"
) ""
) "down-after-milliseconds"
) ""
) "info-refresh"
) ""
) "role-reported"
) "slave"
) "role-reported-time"
) ""
) "master-link-down-time"
) ""
) "master-link-status"
) "ok"
) "master-host"
) "172.60.0.3"
) "master-port"
) ""
) "slave-priority"
) ""
) "slave-repl-offset"
) ""
) ) "name"
) "172.60.0.4:6379"
) "ip"
) "172.60.0.4"
) "port"
) ""
) "runid"
) "f17cfcfc4b9217e1f5a3c0d0a2c55d82da46c37e"
) "flags"
) "slave"
) "link-pending-commands"
) ""
) "link-refcount"
) ""
) "last-ping-sent"
) ""
) "last-ok-ping-reply"
) ""
) "last-ping-reply"
) ""
) "down-after-milliseconds"
) ""
) "info-refresh"
) ""
) "role-reported"
) "slave"
) "role-reported-time"
) ""
) "master-link-down-time"
) ""
) "master-link-status"
) "ok"
) "master-host"
) "172.60.0.3"
) "master-port"
) ""
) "slave-priority"
) ""
) "slave-repl-offset"
) ""
查看主节点的端口
127.0.0.1:> sentinel get-master-addr-by-name mymaster
) "172.60.0.3"
) ""
执行sentinel failover mymaster命令，强制切换主节点！下图所示，发现主节点已经由172.60.0.3变为172.60.0.2了，
待更。。。。