Redis相关内容分享--5

Redis的主从集群实操

沿用在上面单实例的的安装和部署过程，我们创建出来一个6379的单实例之后，对单实例进行主从搭建；

上面的单实例我们的

端口：6379 ；

数据目录：/usr/local/redis/db/db1 ；

配置文件：/usr/local/redis/etc/redis.conf

建立两个从库：

端口：6380/6390；

数据目录：/usr/local/redis/db/db2；

配置文件：/usr/local/redis/etc/redis_6380.conf /usr/local/redis/etc/redis_6390.conf

从库需要配置：

slave-serve-stale-data yes
# slaveof <masterip> <masterport>下面添加一句
slaveof 127.0.0.1 6379
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/usr/local/redis/etc/redis.conf 和/usr/local/redis/etc/redis_6380.conf差异：

root@VM-2-10-ubuntu:/usr/local/redis/etc# diff redis.conf redis_6380.conf 
98c98
< port 6379
---
> port 6380
305c305
< logfile "/var/log/redis.log"
---
> logfile "/var/log/redis_6380.log"
433c433
< # The filename where to dump the DB
---
> # The filename where to dump the 
457c457
< dir "/usr/local/redis/db/db1"
---
> dir "/usr/local/redis/db/db2"
2054a2055,2059
> 
> slave-serve-stale-data yes
> # slaveof <masterip> <masterport>下面添加一句
>  slaveof 127.0.0.1 6379
> 
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redis_6380.conf和 redis_6390.conf差异对比：

root@VM-2-10-ubuntu:/usr/local/redis/etc# diff redis_6380.conf redis_6390.conf 
98c98
< port 6380
---
> port 6390
305c305
< logfile "/var/log/redis_6380.log"
---
> logfile "/var/log/redis_6390.log"
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查看主从状态

在主库查看info replication主从复制情况：

root@VM-2-10-ubuntu:~# redis-cli -p 6379
127.0.0.1:6379> info replication
# Replication
role:master
connected_slaves:2
slave0:ip=127.0.0.1,port=6380,state=online,offset=3632438,lag=1
slave1:ip=127.0.0.1,port=6390,state=online,offset=3632305,lag=1
master_failover_state:no-failover
master_replid:88d24111b1431d617cd53be507e5a254175b05ab
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:3632438
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:2583863
repl_backlog_histlen:1048576
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在从库查看info replication主从复制情况：

127.0.0.1:6380> info replication
# Replication
role:slave
master_host:127.0.0.1
master_port:6379
master_link_status:up
master_last_io_seconds_ago:1
master_sync_in_progress:0
slave_read_repl_offset:3631892
slave_repl_offset:3631892
slave_priority:100
slave_read_only:1
replica_announced:1
connected_slaves:0
master_failover_state:no-failover
master_replid:88d24111b1431d617cd53be507e5a254175b05ab
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:3631892
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:2583317
repl_backlog_histlen:1048576
127.0.0.1:6380> 
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哨兵实操

配置信息：

root@VM-2-10-ubuntu:/usr/local/redis/etc# cat sentinel.conf |grep -v ^#|grep -v ^$
port 26379
daemonize no
pidfile "/var/run/redis-sentinel.pid"
logfile "/var/log/redis_sentinel.log"
dir "/usr/local/redis/db/db_sentinel"
sentinel monitor mymaster 127.0.0.1 6379 2
sentinel down-after-milliseconds mymaster 30000
acllog-max-len 128
sentinel parallel-syncs mymaster 1
sentinel failover-timeout mymaster 180000
sentinel deny-scripts-reconfig yes
SENTINEL resolve-hostnames no
SENTINEL announce-hostnames no
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以上除了logfile、dir 皆为默认配置

启动哨兵：

root@VM-2-10-ubuntu:/usr/local/redis/etc# redis-sentinel /usr/local/redis/etc/sentinel.conf  &
[1] 255020
root@VM-2-10-ubuntu:/usr/local/redis/etc# ps axu |grep sentinel
root      255020  0.0  0.0  52288  5732 pts/5    Sl   17:49   0:00 redis-sentinel *:26379 [sentinel]
root      255459  0.0  0.0   6432   652 pts/5    S+   17:52   0:00 grep --color=auto sentinel
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启动方式可以选择：

redis-server /path/to/sentinel.conf --sentinel
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再看看配置文件信息：

root@VM-2-10-ubuntu:/usr/local/redis/etc# cat sentinel.conf |grep -v ^#|grep -v ^$
port 26379
daemonize no
pidfile "/var/run/redis-sentinel.pid"
logfile "/var/log/redis_sentinel.log"
dir "/usr/local/redis/db/db_sentinel"
sentinel monitor mymaster 127.0.0.1 6379 2
acllog-max-len 128
sentinel deny-scripts-reconfig yes
sentinel resolve-hostnames no
sentinel announce-hostnames no
protected-mode no
user default on nopass ~* &* +@all
sentinel myid 5daa0098ecfe36fc47757e0b3277aa2bbfd2891b
sentinel config-epoch mymaster 0
sentinel leader-epoch mymaster 0
sentinel current-epoch 0
sentinel known-replica mymaster 127.0.0.1 6380
sentinel known-replica mymaster 127.0.0.1 6390
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可以看到最后两行已经同步了redis的从的相关信息数据

哨兵集群

哨兵集群至少要启动三个节点

配置sentinel的26380配置文件：

root@VM-2-10-ubuntu:/usr/local/redis/etc# cp sentinel.conf sentinel_26380.conf
复制

修改sentinel_26380.conf配置文件的内容：

port 26380
pidfile "/var/run/redis-sentinel_26380.pid"
logfile "/var/log/redis_sentinel_26380.log"
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同样的增加sentinel_26390配置文件，启动两个哨兵实例：

root@VM-2-10-ubuntu:/usr/local/redis/etc# redis-sentinel /usr/local/redis/etc/sentinel_26380.conf  &
[1] 390865
root@VM-2-10-ubuntu:/usr/local/redis/etc# redis-sentinel /usr/local/redis/etc/sentinel_26390.conf  &
[2] 391273


root@VM-2-10-ubuntu:/usr/local/redis/etc# ps axu |grep sentinel
root 255020  0.0  0.0  52288  5628 ? Sl Aug09   0:46 redis-sentinel *:26379 [sentinel]
root 390268  0.0  0.0   5512   580 pts/1 S+ 09:11   0:00 tail -f /var/log/redis_sentinel.log
root 390865  0.1  0.0  52288  5672 pts/2 Sl 09:14   0:00 redis-sentinel *:26380 [sentinel]
root 391273  0.1  0.0  52288  5720 pts/2 Sl 09:16   0:00 redis-sentinel *:26390 [sentinel]
root 391301  0.0  0.0   6432   716 pts/2 R+  09:16   0:00 grep --color=auto sentinel
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监控第一个哨兵的日志文件会有以下日志：

root@VM-2-10-ubuntu:/usr/local/redis/etc# tail -f /var/log/redis_sentinel.log
255020:X 10 Aug 2022 09:14:40.492 * +sentinel sentinel 021ce8f5af32facc05ccf3c30006f3b7876b3491 127.0.0.1 26380 @ mymaster 127.0.0.1 6379
255020:X 10 Aug 2022 09:16:46.074 * +sentinel sentinel 2555a6587a07250ea030f46abc02ab761fecc585 127.0.0.1 26390 @ mymaster 127.0.0.1 6379
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测试哨兵

停止主库：

redis-cli -p 6379 shutdown
复制

监控哨兵日志情况：

255020:X 10 Aug 2022 09:24:09.758 # +sdown master mymaster 127.0.0.1 6379
255020:X 10 Aug 2022 09:24:09.816 # +odown master mymaster 127.0.0.1 6379 #quorum 3/2
255020:X 10 Aug 2022 09:24:09.816 # +new-epoch 1
255020:X 10 Aug 2022 09:24:09.816 # +try-failover master mymaster 127.0.0.1 6379
255020:X 10 Aug 2022 09:24:09.821 # +vote-for-leader 5daa0098ecfe36fc47757e0b3277aa2bbfd2891b 1
255020:X 10 Aug 2022 09:24:09.821 # 021ce8f5af32facc05ccf3c30006f3b7876b3491 voted for 021ce8f5af32facc05ccf3c30006f3b7876b3491 1
255020:X 10 Aug 2022 09:24:09.826 # 2555a6587a07250ea030f46abc02ab761fecc585 voted for 021ce8f5af32facc05ccf3c30006f3b7876b3491 1
255020:X 10 Aug 2022 09:24:10.739 # +config-update-from sentinel 021ce8f5af32facc05ccf3c30006f3b7876b3491 127.0.0.1 26380 @ mymaster 127.0.0.1 6379
255020:X 10 Aug 2022 09:24:10.739 # +switch-master mymaster 127.0.0.1 6379 127.0.0.1 6380
255020:X 10 Aug 2022 09:24:10.740 * +slave slave 127.0.0.1:6390 127.0.0.1 6390 @ mymaster 127.0.0.1 6380
255020:X 10 Aug 2022 09:24:10.740 * +slave slave 127.0.0.1:6379 127.0.0.1 6379 @ mymaster 127.0.0.1 6380

255020:X 10 Aug 2022 09:24:40.759 # +sdown slave 127.0.0.1:6379 127.0.0.1 6379 @ mymaster 127.0.0.1 6380
复制

到6380查看复制状态：

127.0.0.1:6380> info replication
# Replication
role:master
connected_slaves:1
slave0:ip=127.0.0.1,port=6390,state=online,offset=4322388,lag=1
master_failover_state:no-failover
master_replid:8c5a11758bffb00a7957dd7a083e3f7e238c8135
master_replid2:88d24111b1431d617cd53be507e5a254175b05ab
master_repl_offset:4322521
second_repl_offset:3801181
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:3273946
repl_backlog_histlen:1048576
复制

再次启动6379实例，查看状态：

root@VM-2-10-ubuntu:~# redis-server /usr/local/redis/etc/redis.conf &
root@VM-2-10-ubuntu:~# redis-cli -p 6380
127.0.0.1:6380> info replication
# Replication
role:master
connected_slaves:2
slave0:ip=127.0.0.1,port=6390,state=online,offset=4408133,lag=0
slave1:ip=127.0.0.1,port=6379,state=online,offset=4408133,lag=1
master_failover_state:no-failover
master_replid:8c5a11758bffb00a7957dd7a083e3f7e238c8135
master_replid2:88d24111b1431d617cd53be507e5a254175b05ab
master_repl_offset:4408133
second_repl_offset:3801181
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:3359558
repl_backlog_histlen:1048576
复制

Sentinel命令

下面是可以接收的命令列表，没有覆盖到那些用来改变Sentinel配置的命令：

• PING 这个命令仅仅返回PONG。
• SENTINEL masters 展示监控的主节点和它们的状态列表
• SENTINEL master 展示指定的主节点的信息
• SENTINEL salves 展示这个主节点的从节点，以及它们的状态
• SENTINEL sentinels 展示这个主节点的sentinel实例，以及它们的状态
• SENTINEL get-master-addr-by-name 返回主节点的IP和端口号。如果这个主节点的一次故障转移正在进行，就返回提升的从节点的IP和端口号
• SENTINEL reset <pattern> 这个命令将会根据匹配的名称重置主节点，pattern参数是通配符（glob-style）类型，重置进程清除主节点中之前的所有状态，并且移除主节点发现和关联的从节点和sentinel。
• SENTINEL failover <master name> 如果主节点不可达，强制开始故障转移，不需要另外的Sentinels同意。
• SENTINEL ckquorum <master name> 检查当前的Sentinel配置对于主节点的故障转移是否能达到仲裁人数，并且大多数是需要的来授权故障转移。这个命令应该在监控系统中使用来检查一个Sentinel部署是否正常。
• SENTINEL flushconfig 强制Sentinel重新写入它的配置到磁盘上，包括当前Sentinel状态。通常，每次当它状态里的一些东西改变，Sentinel就会重写配置信息。然而有时候配置文件会丢失，由于错误的操作、磁盘故障、包升级脚本、或配置管理。在那种情况下，强制Sentinel重写它的配置文件是容易的。甚至之前的配置文件完全丢失，这个命令也能很好的工作。