Redis哨兵模式（sentinel）部署记录（主从复制、读写分离、主从切换）

时间：2021-12-18 07:48:21

部署环境: CentOS7.5 

192.168.94.11 (master)

192.168.94.22 (slave0)

192.168.94.33 (slave1)

192.168.94.44 (slave2)

所有节点都需要安装redis+sentinel

[root@master ~]# tar xf redis-4.0..tar.gz -C  /usr/local/src/

[root@master ~]# cd /usr/local/src/redis-4.0./

[root@master redis-4.0.]# make && make PREFIX=/usr/local/redis install

[root@master redis-4.0.]# cd /usr/local/redis/

[root@master redis]# mkdir run conf log dir

[root@master redis]# ln -s /usr/local/redis/bin/* /usr/local/bin/

所有节点修改redis和sentinel配置文件

[root@master redis]# cp /usr/local/src/redis-4.0./redis.conf conf/

bind 0.0.0.0

protected-mode no

port

tcp-backlog

timeout

tcp-keepalive

daemonize yes

supervised no

pidfile /usr/local/redis/run/redis_6379.pid

loglevel notice

logfile "/usr/local/redis/log/redis_6379.log"

databases

always-show-logo yes

save

save

save

stop-writes-on-bgsave-error yes

rdbcompression yes

rdbchecksum yes

dbfilename dump.rdb

dir /usr/local/redis/dir

slave-serve-stale-data yes

slave-read-only yes

repl-diskless-sync no

repl-diskless-sync-delay

repl-disable-tcp-nodelay no

slave-priority

lazyfree-lazy-eviction no

lazyfree-lazy-expire no

lazyfree-lazy-server-del no

slave-lazy-flush no

appendonly yes

appendfilename "appendonly.aof"

appendfsync everysec

no-appendfsync-on-rewrite no

auto-aof-rewrite-percentage

auto-aof-rewrite-min-size 64mb

aof-load-truncated yes

aof-use-rdb-preamble no

lua-time-limit

slowlog-log-slower-than

slowlog-max-len

latency-monitor-threshold

notify-keyspace-events ""

hash-max-ziplist-entries

hash-max-ziplist-value

list-max-ziplist-size -

list-compress-depth

set-max-intset-entries

zset-max-ziplist-entries

zset-max-ziplist-value

hll-sparse-max-bytes

activerehashing yes

client-output-buffer-limit normal

client-output-buffer-limit slave 256mb 64mb

client-output-buffer-limit pubsub 32mb 8mb

hz

aof-rewrite-incremental-fsync yes

# slave上要添加一条: slaveof 192.168.94.11 

[root@master redis]# cp /usr/local/src/redis-4.0./sentinel.conf conf/

[root@master ~]# grep -Ev "^#|^$" /usr/local/redis/conf/sentinel.conf

port

pidfile "/usr/local/redis/run/redis-sentinel.pid"

dir "/usr/local/redis/dir/"

daemonize yes

protected-mode no

logfile "/usr/local/redis/log/redis-sentinel.log"

sentinel monitor mymaster 192.168.94.11

sentinel down-after-milliseconds mymaster

sentinel parallel-syncs mymaster

sentinel failover-timeout mymaster

添加redis到系统服务

[root@master redis]# cp /usr/local/src/redis-4.0./utils/redis_init_script /etc/init.d/redis

[root@master ~]# vim /etc/init.d/redis

#!/bin/sh

#

# Simple Redis init.d script conceived to work on Linux systems

# as it does use of the /proc filesystem.

### BEGIN INIT INFO

# Provides:     redis_6379

# Default-Start:

# Default-Stop:

# Short-Description:    Redis data structure server

# Description:          Redis data structure server. See https://redis.io

### END INIT INFO

REDISPORT=

EXEC=/usr/local/bin/redis-server

CLIEXEC=/usr/local/bin/redis-cli

PIDFILE=/usr/local/redis/run/redis_${REDISPORT}.pid

CONF="/usr/local/redis/conf/redis.conf"

case "$1" in

    start)

        if [ -f $PIDFILE ]

        then

                echo "$PIDFILE exists, process is already running or crashed"

        else

                echo "Starting Redis server..."

                $EXEC $CONF

        fi

        ;;

    stop)

        if [ ! -f $PIDFILE ]

        then

                echo "$PIDFILE does not exist, process is not running"

        else

                PID=$(cat $PIDFILE)

                echo "Stopping ..."

                $CLIEXEC -p $REDISPORT shutdown

                while [ -x /proc/${PID} ]

                do

                    echo "Waiting for Redis to shutdown ..."

                    sleep

                done

                echo "Redis stopped"

        fi

        ;;

    *)

        echo "Please use start or stop as first argument"

        ;;

esac

[root@master redis]# chkconfig --add redis

[root@master redis]# systemctl daemon-reload

所有节点启动redis、sentinel服务器

[root@master redis]# systemctl start redis

[root@master redis]# systemctl status redis

● redis.service - LSB: Redis data structure server

   Loaded: loaded (/etc/rc.d/init.d/redis; bad; vendor preset: disabled)

   Active: active (running) since 三 -- :: CST; 3s ago

     Docs: man:systemd-sysv-generator()

  Process:  ExecStart=/etc/rc.d/init.d/redis start (code=exited, status=/SUCCESS)

   CGroup: /system.slice/redis.service

           └─ /usr/local/bin/redis-server 0.0.0.0:

9月  :: master systemd[]: Starting LSB: Redis data structure server...

9月  :: master redis[]: Starting Redis server...

9月  :: master systemd[]: Started LSB: Redis data structure server.

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

[root@master redis]# netstat -antup|grep

tcp               0.0.0.0:           0.0.0.0:*               LISTEN      /redis-sentine

tcp6              :::                :::*                    LISTEN      /redis-sentine

查看redis和sentinel信息

# 查看节点redis的主从关系

[root@master redis]# redis-cli -h 192.168.94.11 -p  info|grep role

role:master

[root@master redis]# redis-cli -h 192.168.94.22 -p  info|grep role

role:slave

[root@master redis]# redis-cli -h 192.168.94.33 -p  info|grep role

role:slave

[root@master redis]# redis-cli -h 192.168.94.44 -p  info|grep role

role:slave

# 查看master节点信息

[root@master redis]# redis-cli -h 192.168.94.11 -p  info Replication

# Replication

role:master

connected_slaves:

slave0:ip=192.168.94.33,port=,state=online,offset=,lag=

slave1:ip=192.168.94.44,port=,state=online,offset=,lag=

slave2:ip=192.168.94.22,port=,state=online,offset=,lag=

master_replid:bf73c242b680e63743aa9d46b510ad1aee56105e

master_replid2:

master_repl_offset:

second_repl_offset:-

repl_backlog_active:

repl_backlog_size:

repl_backlog_first_byte_offset:

repl_backlog_histlen:

# 查看master的sentinel配置文件 , 末尾被写入如下内容

[root@master redis]# grep -Ev '^#|^$' /usr/local/redis/conf/sentinel.conf

port

dir "/usr/local/redis/dir"

sentinel myid 2b92a48338bcd05968782fb3e4af432ad388e1c6

sentinel deny-scripts-reconfig yes

sentinel monitor mymaster 192.168.94.11

sentinel down-after-milliseconds mymaster

sentinel failover-timeout mymaster

pidfile "/usr/local/redis/run/redis_sentinel.pid"

logfile "/usr/local/redis/log/redis_sentinel.log"

daemonize yes

sentinel config-epoch mymaster

sentinel leader-epoch mymaster

sentinel known-slave mymaster 192.168.94.33

sentinel known-slave mymaster 192.168.94.22

sentinel known-slave mymaster 192.168.94.44

sentinel known-sentinel mymaster 192.168.94.33  cd7c8822acb184eb1af4f96710fc93f5073cfc65

sentinel known-sentinel mymaster 192.168.94.44  be0477f4855b523160d2e487172b94dc1a4c6181

sentinel known-sentinel mymaster 192.168.94.22  f464afa0fb23eb3561e2a448b10a01cdee130d06

sentinel current-epoch 

# 查看slave0的节点信息

[root@slave0 ~]# redis-cli -h 192.168.94.33 -p  info Replication

# Replication

role:slave

master_host:192.168.94.11

master_port:

master_link_status:up

master_last_io_seconds_ago:

master_sync_in_progress:

slave_repl_offset:

slave_priority:

slave_read_only:

connected_slaves:

master_replid:bf73c242b680e63743aa9d46b510ad1aee56105e

master_replid2:

master_repl_offset:

second_repl_offset:-

repl_backlog_active:

repl_backlog_size:

repl_backlog_first_byte_offset:

repl_backlog_histlen:

# 查看slave的sentinel配置文件 , 在末尾处被写入如下内容

[root@slave0 ~]# grep -Ev '^#|^$' /usr/local/redis/conf/sentinel.conf

port

dir "/usr/local/redis/dir"

sentinel myid cd7c8822acb184eb1af4f96710fc93f5073cfc65

sentinel deny-scripts-reconfig yes

sentinel monitor mymaster 192.168.94.11

sentinel down-after-milliseconds mymaster

sentinel failover-timeout mymaster

pidfile "/usr/local/redis/run/redis_sentinel.pid"

logfile "/usr/local/redis/log/redis_sentinel.log"

daemonize yes

sentinel config-epoch mymaster

sentinel leader-epoch mymaster

sentinel known-slave mymaster 192.168.94.22

sentinel known-slave mymaster 192.168.94.33

sentinel known-slave mymaster 192.168.94.44

sentinel known-sentinel mymaster 192.168.94.22  f464afa0fb23eb3561e2a448b10a01cdee130d06

sentinel known-sentinel mymaster 192.168.94.11  2b92a48338bcd05968782fb3e4af432ad388e1c6

sentinel known-sentinel mymaster 192.168.94.44  be0477f4855b523160d2e487172b94dc1a4c6181

sentinel current-epoch

# 其他slave节点也是一样的

测试客户端写入数据

[root@master redis]# redis-cli -h 192.168.94.11 -p

192.168.94.11:> set mywife limingming

OK

192.168.94.11:> get mywife

"limingming"

192.168.94.11:> exit

# 客户端连接任意slave节点get上面的数据

[root@master redis]# redis-cli -h 192.168.94.22 -p

192.168.94.22:> get mywife

"limingming"

192.168.94.22:> set limingming xiaoxiannv

(error) READONLY You can't write against a read only slave.

# 测试可见 , master节点可以写入 , slave节点默认是只读 ,不能写入

到这就已经实现主从复制 , 读写分离了

通过sentinel实现主从切换 , sentinel需要做高可用防止单点

# 关闭任意slave节点 , 查看状态

[root@master redis]# redis-cli -h 192.168.94.22 -p

192.168.94.22:> get mywife

"limingming"

192.168.94.22:> SHUTDOWN

not connected> exit

# 查看剩余节点信息

[root@master redis]# redis-cli -h 192.168.94.11 -p  info replication

# Replication

role:master

connected_slaves:     # 由3变成2了 , 减少了一台slave

slave0:ip=192.168.94.33,port=,state=online,offset=,lag=

slave1:ip=192.168.94.44,port=,state=online,offset=,lag=

master_replid:bf73c242b680e63743aa9d46b510ad1aee56105e

master_replid2:

master_repl_offset:

second_repl_offset:-

repl_backlog_active:

repl_backlog_size:

repl_backlog_first_byte_offset:

repl_backlog_histlen:

# 在任意节点查看sentinel日志 ,  发现slave已经是sdown状态

[root@master redis]# tailf /usr/local/redis/log/redis_sentinel.log

:X  Sep ::26.759 * +sentinel sentinel f464afa0fb23eb3561e2a448b10a01cdee130d06 192.168.94.22  @ mymaster 192.168.94.11

:X  Sep ::27.287 * +sentinel sentinel be0477f4855b523160d2e487172b94dc1a4c6181 192.168.94.44  @ mymaster 192.168.94.11

:X  Sep ::27.551 * +sentinel sentinel cd7c8822acb184eb1af4f96710fc93f5073cfc65 192.168.94.33  @ mymaster 192.168.94.11

:X  Sep ::35.097 * +slave slave 192.168.94.33: 192.168.94.33  @ mymaster 192.168.94.11

:X  Sep ::35.098 * +slave slave 192.168.94.44: 192.168.94.44  @ mymaster 192.168.94.11

:X  Sep ::36.796 # +sdown sentinel f464afa0fb23eb3561e2a448b10a01cdee130d06 192.168.94.22  @ mymaster 192.168.94.11

:X  Sep ::37.327 # +sdown sentinel be0477f4855b523160d2e487172b94dc1a4c6181 192.168.94.44  @ mymaster 192.168.94.11

:X  Sep ::37.560 # +sdown sentinel cd7c8822acb184eb1af4f96710fc93f5073cfc65 192.168.94.33  @ mymaster 192.168.94.11

:X  Sep ::45.100 * +slave slave 192.168.94.22: 192.168.94.22  @ mymaster 192.168.94.11

:X  Sep ::46.255 # +sdown slave 192.168.94.22: 192.168.94.22  @ mymaster 192.168.94.11 

# 然后重启上面被关闭的节点 ,  所有节点的sentinel都可以检测到slave已处于可用状态，此时再来查看节点的主从信息

[root@master redis]# redis-cli -h 192.168.94.11 -p  info replication

# Replication

role:master

connected_slaves:

slave0:ip=192.168.94.33,port=,state=online,offset=,lag=

slave1:ip=192.168.94.44,port=,state=online,offset=,lag=

slave2:ip=192.168.94.22,port=,state=online,offset=,lag=

master_replid:bf73c242b680e63743aa9d46b510ad1aee56105e

master_replid2:

master_repl_offset:

second_repl_offset:-

repl_backlog_active:

repl_backlog_size:

repl_backlog_first_byte_offset:

repl_backlog_histlen:

# 日志已经显示slave进入-sdown状态

[root@master redis]# tailf /usr/local/redis/log/redis_sentinel.log

:X  Sep ::26.759 * +sentinel sentinel f464afa0fb23eb3561e2a448b10a01cdee130d06 192.168.94.22  @ mymaster 192.168.94.11

:X  Sep ::27.287 * +sentinel sentinel be0477f4855b523160d2e487172b94dc1a4c6181 192.168.94.44  @ mymaster 192.168.94.11

:X  Sep ::27.551 * +sentinel sentinel cd7c8822acb184eb1af4f96710fc93f5073cfc65 192.168.94.33  @ mymaster 192.168.94.11

:X  Sep ::35.097 * +slave slave 192.168.94.33: 192.168.94.33  @ mymaster 192.168.94.11

:X  Sep ::35.098 * +slave slave 192.168.94.44: 192.168.94.44  @ mymaster 192.168.94.11

:X  Sep ::36.796 # +sdown sentinel f464afa0fb23eb3561e2a448b10a01cdee130d06 192.168.94.22  @ mymaster 192.168.94.11

:X  Sep ::37.327 # +sdown sentinel be0477f4855b523160d2e487172b94dc1a4c6181 192.168.94.44  @ mymaster 192.168.94.11

:X  Sep ::37.560 # +sdown sentinel cd7c8822acb184eb1af4f96710fc93f5073cfc65 192.168.94.33  @ mymaster 192.168.94.11

:X  Sep ::45.100 * +slave slave 192.168.94.22: 192.168.94.22  @ mymaster 192.168.94.11

:X  Sep ::46.255 # +sdown slave 192.168.94.22: 192.168.94.22  @ mymaster 192.168.94.11

:X  Sep ::01.203 * +reboot slave 192.168.94.22: 192.168.94.22  @ mymaster 192.168.94.11

:X  Sep ::01.261 # -sdown slave 192.168.94.22: 192.168.94.22  @ mymaster 192.168.94.11

关掉master节点 , 观察slave节点

[root@master ~]# redis-cli -h 192.168.94.11 -p

192.168.94.11:> SHUTDOWN

# 在任意节点查看sentinel日志 , 发现master已经是+sdown的状态

[root@slave2 ~]# tailf /usr/local/redis/log/redis_sentinel.log

:X  Sep ::30.806 * +slave-reconf-done slave 192.168.94.33: 192.168.94.33  @ mymaster 192.168.94.11

:X  Sep ::30.869 * +slave-reconf-sent slave 192.168.94.22: 192.168.94.22  @ mymaster 192.168.94.11

:X  Sep ::31.821 * +slave-reconf-inprog slave 192.168.94.22: 192.168.94.22  @ mymaster 192.168.94.11

:X  Sep ::31.821 * +slave-reconf-done slave 192.168.94.22: 192.168.94.22  @ mymaster 192.168.94.11

:X  Sep ::31.910 # +failover-end master mymaster 192.168.94.11

:X  Sep ::31.911 # +switch-master mymaster 192.168.94.11  192.168.94.44

:X  Sep ::31.911 * +slave slave 192.168.94.33: 192.168.94.33  @ mymaster 192.168.94.44

:X  Sep ::31.911 * +slave slave 192.168.94.22: 192.168.94.22  @ mymaster 192.168.94.44

:X  Sep ::31.911 * +slave slave 192.168.94.11: 192.168.94.11  @ mymaster 192.168.94.44

:X  Sep ::41.995 # +sdown slave 192.168.94.11: 192.168.94.11  @ mymaster 192.168.94.44 

[root@slave2 ~]# redis-cli -h 192.168.94.22 -p  info |grep role

role:slave

[root@slave2 ~]# redis-cli -h 192.168.94.33 -p  info |grep role

role:slave

[root@slave2 ~]# redis-cli -h 192.168.94.44 -p  info |grep role

role:master

[root@slave2 ~]# redis-cli -h 192.168.94.44 -p  info replication

# Replication

role:master

connected_slaves:

slave0:ip=192.168.94.33,port=,state=online,offset=,lag=

slave1:ip=192.168.94.22,port=,state=online,offset=,lag=

master_replid:6b197e5e8a9f6b146558a21552e7eb9f30926289

master_replid2:086f725685de634b2b3efd546d150a370e461d07

master_repl_offset:

second_repl_offset:

repl_backlog_active:

repl_backlog_size:

repl_backlog_first_byte_offset:

repl_backlog_histlen:

# 可以看出 , 当master节点(192.168.94.11)的redis关闭后 , slave节点(192.168.94.44)变成了新的master

# 在这个新的master上进行写的操作是可以执行的

[root@slave1 ~]# redis-cli -h 192.168.94.44 -p

192.168.94.44:> set mywife limingming

OK

192.168.94.44:> get mywife

"limingming"

# 重启192.168.94.11节点的redis , 等待所有节点的sentinel都检测到后 ,查看所有节点的主从信息 , 现有的master节点是不会被强占去的 , 而原来192.168.94.11节点的角色由master变成了slave

[root@slave1 ~]# redis-cli -h 192.168.94.44 -p  info | grep role

role:master

[root@slave1 ~]# redis-cli -h 192.168.94.22 -p  info | grep role

role:slave

[root@slave1 ~]# redis-cli -h 192.168.94.33 -p  info | grep role

role:slave

[root@slave1 ~]# redis-cli -h 192.168.94.11 -p  info | grep role

role:slave

[root@slave1 ~]# redis-cli -h 192.168.94.44 -p  info replication

# Replication

role:master

connected_slaves:

slave0:ip=192.168.94.33,port=,state=online,offset=,lag=

slave1:ip=192.168.94.22,port=,state=online,offset=,lag=

slave2:ip=192.168.94.11,port=,state=online,offset=,lag=

master_replid:6b197e5e8a9f6b146558a21552e7eb9f30926289

master_replid2:086f725685de634b2b3efd546d150a370e461d07

master_repl_offset:

second_repl_offset:

repl_backlog_active:

repl_backlog_size:

repl_backlog_first_byte_offset:

repl_backlog_histlen:

# 所有slave将同步新的master上的信息 
主从故障切换已经实现了

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