Redis配置文件详解： http://donald-draper.iteye.com/blog/2346275
Reid高可用Sentinel配置文件详解： http://donald-draper.iteye.com/blog/2346606
Redis 的 Sentinel 文档： http://www.redis.cn/topics/sentinel.html
redis的主从复制，读写分离，主从切换: http://www.tuicool.com/articles/3MneIbz
Redis主从同步，读写分离: http://www.tuicool.com/articles/vyiUveq
环境Centos7，redis-3.0.5
Master-Centos7
ip 运行进程 内存 硬盘
192.168.126.128 redis sentinel 2G 30G
Slave-Centos7
192.168.126.133 redis sentinel 1.5G 30G
192.168.126.138 redis sentinel 1.5G 30G
Master的配置，我们在前文中已讲，这里不再说了，直接配置slave
#拷贝安装文件到slave
[redis@agent133 Downloads]$ scp 192.168.126.128：/home/redis/Downloads/redis-3.0.5.tar.gz [redis@agent133 Downloads]$ ls redis-3.0.5.tar.gz
解压，按照我们前面的redis安装配置文章，安装redis
###从Mater拷贝redis配置文件
[root@agent133 redis-3.0.5]# cd /usr/local/redis/conf/ [root@agent133 conf]# ls -al total 0 drwxr-xr-x. 2 root root 6 Dec 21 17:12 . drwxr-xr-x. 4 root root 27 Dec 21 17:12 .. [root@agent133 conf]# scp 192.168.126.128:/usr/local/redis/conf/redis.conf . The authenticity of host '192.168.126.128 (192.168.126.128)' can't be established. ECDSA key fingerprint is 75:80:da:08:ea:2d:9d:3d:da:7c:b1:1f:71:7d:b1:a5. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '192.168.126.128' (ECDSA) to the list of known hosts. [email protected]'s password: redis.conf 100% 41KB 40.6KB/s 00:00 [root@agent133 conf]# ls -al total 44 drwxr-xr-x. 2 root root 23 Dec 21 17:13 . drwxr-xr-x. 4 root root 27 Dec 21 17:12 .. -rw-r--r--. 1 root root 41584 Dec 21 17:13 redis.conf
拷贝数据目录及日志目录/redis
[root@agent133 conf]# cd / [root@agent133 /]# ls bin boot dev etc home lib lib64 media mnt mysql opt proc root run sbin srv sys tmp usr var zabbix [root@agent133 /]# scp -r 192.168.126.128:/redis . [email protected]'s password: redis.log 100% 19KB 19.1KB/s 00:00 redis.sh 100% 1338 1.3KB/s 00:00 appendonly.aof 100% 245 0.2KB/s 00:00 dump.rdb 100% 18 0.0KB/s 00:00 [root@agent133 /]# ls -al total 48 dr-xr-xr-x. 20 root root 4096 Dec 21 17:17 . dr-xr-xr-x. 20 root root 4096 Dec 21 17:17 .. lrwxrwxrwx. 1 root root 7 Jun 24 17:17 bin -> usr/bin dr-xr-xr-x. 4 root root 4096 Jun 27 10:54 boot drwxr-xr-x. 20 root root 3280 Dec 21 16:53 dev drwxr-xr-x. 142 root root 12288 Dec 21 16:59 etc drwxr-xr-x. 6 root root 57 Dec 21 10:27 home lrwxrwxrwx. 1 root root 7 Jun 24 17:17 lib -> usr/lib lrwxrwxrwx. 1 root root 9 Jun 24 17:17 lib64 -> usr/lib64 drwxr-xr-x. 2 root root 6 Aug 12 2015 media drwxr-xr-x. 2 root root 6 Aug 12 2015 mnt drwxr-xr-x. 2 mysql root 6 Jun 29 17:36 mysql drwxr-xr-x. 3 root root 15 Aug 12 2015 opt dr-xr-xr-x. 450 root root 0 Dec 21 16:52 proc drwxr-xr-x. 5 root root 38 Dec 21 17:17 redis dr-xr-x---. 5 root root 4096 Dec 21 17:13 root drwxr-xr-x. 39 root root 1180 Dec 21 16:59 run lrwxrwxrwx. 1 root root 8 Jun 24 17:17 sbin -> usr/sbin drwxr-xr-x. 2 root root 6 Aug 12 2015 srv dr-xr-xr-x. 13 root root 0 Dec 21 16:52 sys drwxrwxrwt. 17 root root 4096 Dec 21 17:12 tmp drwxr-xr-x. 13 root root 4096 Jul 4 11:41 usr drwxr-xr-x. 23 root root 4096 Dec 21 16:52 var drwxrwxr-x. 4 zabbix mysql 4096 Aug 11 15:58 zabbix [root@agent133 /]#
##清除原先的数据文件及日志文件
[root@agent133 /]# cd redis/ [root@agent133 redis]# ls bin data logs [root@agent133 redis]# cd data/ [root@agent133 data]# ls -al total 8 drwxr-xr-x. 2 root root 42 Dec 21 17:17 . drwxr-xr-x. 5 root root 38 Dec 21 17:17 .. -rw-r--r--. 1 root root 245 Dec 21 17:17 appendonly.aof -rw-r--r--. 1 root root 18 Dec 21 17:17 dump.rdb [root@agent133 data]# rm ./* rm: remove regular file ‘./appendonly.aof’? y rm: remove regular file ‘./dump.rdb’? y [root@agent133 data]# ls -al total 0 drwxr-xr-x. 2 root root 6 Dec 21 17:18 . drwxr-xr-x. 5 root root 38 Dec 21 17:17 .. [root@agent133 data]# cd .. [root@agent133 redis]# ls bin data logs [root@agent133 redis]# cd logs/ [root@agent133 logs]# ls -al total 20 drwxr-xr-x. 2 root root 22 Dec 21 17:17 . drwxr-xr-x. 5 root root 38 Dec 21 17:17 .. -rw-r--r--. 1 root root 19546 Dec 21 17:17 redis.log [root@agent133 logs]# > redis.log [root@agent133 logs]# tail redis.log [root@agent133 logs]#
修改Slave1配置
[root@agent133 redis]# cd conf/ [root@agent133 conf]# vim redis.conf [root@agent133 conf]# ################################# REPLICATION ################################# # 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. # master的ip和port slaveof 192.168.126.128 6379 # If the master is password protected (using the "requirepass" configuration # directive below) it is possible to tell the slave to authenticate before # starting the replication synchronization process, otherwise the master will # refuse the slave request. # master验证密码 masterauth redis # Since Redis 2.6 by default slaves are read-only. # # Note: read only slaves are not designed to be exposed to untrusted clients # on the internet. It's just a protection layer against misuse of the instance. # Still a read only slave exports by default all the administrative commands # such as CONFIG, DEBUG, and so forth. To a limited extent you can improve # security of read only slaves using 'rename-command' to shadow all the # administrative / dangerous commands. ##slave只读 slave-read-only yes # A slave with a low priority number is considered better for promotion, so # for instance if there are three slaves with priority 10, 100, 25 Sentinel will # pick the one with priority 10, that is the lowest. # # However a special priority of 0 marks the slave as not able to perform the # role of master, so a slave with priority of 0 will never be selected by # Redis Sentinel for promotion. # # By default the priority is 100. ##slave优先级，优先级越低，当master宕机时，成为master的可能性越大 slave-priority 90
##注意slaves的优先级
修改Master文件
# It is possible for a master to stop accepting writes if there are less than # N slaves connected, having a lag less or equal than M seconds. # # The N slaves need to be in "online" state. # # The lag in seconds, that must be <= the specified value, is calculated from # the last ping received from the slave, that is usually sent every second. # # This option does not GUARANTEE that N replicas will accept the write, but # will limit the window of exposure for lost writes in case not enough slaves # are available, to the specified number of seconds. # # For example to require at least 3 slaves with a lag <= 10 seconds use: # ###为了保证集群的一致性，master必须保证salve的在线数量和握手时间满足以下条件才 接受写请求 min-slaves-to-write 1 min-slaves-max-lag 10
为了保证集群的高可用性，我们在Master和slaves上，启动Sentinel，功能与类似与zookeeper。
#从redis安装包中，拷贝sentinel配置文件到 /usr/local/redis/conf/
[root@zabbix redis-3.0.5]# cp sentinel.conf /usr/local/redis/conf/ [root@zabbix redis-3.0.5]# cd /usr/local/redis/conf/ [root@zabbix conf]# ls -al total 52 drwxr-xr-x 2 root root 43 Dec 21 18:20 . drwxr-xr-x 4 root root 27 Dec 19 18:16 .. -rw-r--r-- 1 root root 41580 Dec 21 17:40 redis.conf -rw-r--r-- 1 root root 7109 Dec 21 18:20 sentinel.conf
#创建sentinel工作目录
[root@zabbix redis]# mkdir sentinel [root@zabbix redis]# ls -al total 4 drwxr-xr-x 6 root root 53 Dec 21 18:29 . dr-xr-xr-x. 19 root root 4096 Dec 20 15:16 .. drwxr-xr-x 2 root root 21 Dec 20 15:37 bin drwxr-xr-x 2 root root 42 Dec 21 10:52 data drwxr-xr-x 2 root root 22 Dec 20 15:19 logs drwxr-xr-x 2 root root 6 Dec 21 18:29 sentinel [root@zabbix conf]#
修改sentinel.conf
[root@zabbix conf]# vim sentinel.conf
具体如下，具体下面每个配置的意思，我们前文sentinel配置文件篇中已讲，这里不再赘述，其中zabbix是集群中master-128的主机名，
# port <sentinel-port> # The port that this sentinel instance will run on port 26379 dir /redis/sentinel sentinel monitor zabbix 192.168.126.128 6379 2 sentinel auth-pass zabbix redis sentinel down-after-milliseconds zabbix 30000 sentinel parallel-syncs zabbix 1 sentinel failover-timeout zabbix 180000
#由于我的操作系统是centos，有防火墙，为了Master与slave能够通信，
将6379，与26379两个端口，解除防护，如下，具体可参考相关博文：
http://donald-draper.iteye.com/blog/2315696
[root@zabbix redis]# vim /etc/sysconfig/iptables [root@zabbix redis]# cat /etc/sysconfig/iptables # sample configuration for iptables service # you can edit this manually or use system-config-firewall # please do not ask us to add additional ports/services to this default configuration *filter :INPUT ACCEPT [0:0] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [0:0] -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT -A INPUT -p icmp -j ACCEPT -A INPUT -i lo -j ACCEPT -A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT -A INPUT -p tcp -m state --state NEW -m tcp --dport 80 -j ACCEPT -A INPUT -p tcp -m state --state NEW -m tcp --dport 25 -j ACCEPT -A INPUT -p tcp -m state --state NEW -m tcp --dport 3306 -j ACCEPT -A INPUT -p tcp -m state --state NEW -m tcp --dport 10051 -j ACCEPT -A INPUT -p tcp -m state --state NEW -m tcp --dport 6379 -j ACCEPT -A INPUT -p tcp -m state --state NEW -m tcp --dport 26379 -j ACCEPT -A INPUT -j REJECT --reject-with icmp-host-prohibited -A FORWARD -j REJECT --reject-with icmp-host-prohibited COMMIT
##在slaves上做同样的工作，再启动集群前，确保所有机器6379，26379端口畅通，
如果以上方法解决不了，直接iptables -F
[root@zabbix redis]#
至此sentinel配置完毕，将master的sentinel配置文件拷贝到Slaves上
[root@agent133 redis]# cd conf/ [root@agent133 conf]# ls redis.conf [root@agent133 conf]# scp 192.168.126.128:/usr/local/redis/conf/sentinel.conf . [email protected]'s password: sentinel.conf 100% 7094 6.9KB/s 00:00 [root@agent133 conf]# ls -al total 52 drwxr-xr-x. 2 root root 43 Dec 21 18:40 . drwxr-xr-x. 4 root root 27 Dec 21 17:12 .. -rw-r--r--. 1 root root 41460 Dec 21 17:37 redis.conf -rw-r--r--. 1 root root 7094 Dec 21 18:40 sentinel.conf [root@agent133 conf]#
启动master redis
[root@zabbix redis]# cd bin/ [root@zabbix bin]# ls redis.sh [root@zabbix bin]# ./redis.sh start start redis-server...runing [root@zabbix bin]#
启动master sentinel
[root@zabbix bin]#
[1] 7365
[root@zabbix bin]# 7365:X 21 Dec 18:44:48.955 * Increased maximum number of open files to 10032 (it was originally set to 1024).
_._
_.-``__ ''-._
_.-`` `. `_. ''-._ Redis 3.0.5 (00000000/0) 64 bit
.-`` .-```. ```\/ _.,_ ''-._
( ' , .-` | `, ) Running in sentinel mode
|`-._`-...-` __...-.``-._|'` _.-'| Port: 26379
| `-._ `._ / _.-' | PID: 7365
`-._ `-._ `-./ _.-' _.-'
|`-._`-._ `-.__.-' _.-'_.-'|
| `-._`-._ _.-'_.-' | http://redis.io
`-._ `-._`-.__.-'_.-' _.-'
|`-._`-._ `-.__.-' _.-'_.-'|
| `-._`-._ _.-'_.-' |
`-._ `-._`-.__.-'_.-' _.-'
`-._ `-.__.-' _.-'
`-._ _.-'
`-.__.-'
7365:X 21 Dec 18:44:48.956 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
7365:X 21 Dec 18:44:48.956 # Sentinel runid is b4354571b53ffdbc7369913f3c2c87a31f2a22a4
7365:X 21 Dec 18:44:48.956 # +monitor master zabbix 192.168.126.128 6379 quorum 2
连接Master
[root@zabbix bin]#redis-cli -h localhost -p 6379 -a redis localhost:6379> monitor OK 1482317315.788890 [0 192.168.126.128:40190] "PING" 1482317315.843660 [0 192.168.126.128:40190] "PUBLISH" "__sentinel__:hello" "192.168.126.128,26379,b4354571b53ffdbc7369913f3c2c87a31f2a22a4,0,zabbix,192.168.126.128,6379,0" 1482317316.800317 [0 192.168.126.128:40190] "PING" 1482317317.836785 [0 192.168.126.128:40190] "PING" 1482317317.928621 [0 192.168.126.128:40190] "PUBLISH" "__sentinel__:hello" "192.168.126.128,26379,b4354571b53ffdbc7369913f3c2c87a31f2a22a4,0,zabbix,192.168.126.128,6379,0" 1482317318.871309 [0 192.168.126.128:40190] "PING" 1482317319.950063 [0 192.168.126.128:40190] "INFO"
可以看出sentinel正在监控Master
##连接sentinel查看状态
[root@zabbix bin]# redis-cli -p 26379 127.0.0.1:26379> info # Server redis_version:3.0.5 redis_git_sha1:00000000 redis_git_dirty:0 redis_build_id:2b4372a303619568 redis_mode:sentinel os:Linux 3.10.0-327.22.2.el7.x86_64 x86_64 arch_bits:64 multiplexing_api:epoll gcc_version:4.8.5 process_id:7365 run_id:b4354571b53ffdbc7369913f3c2c87a31f2a22a4 tcp_port:26379 uptime_in_seconds:1211 uptime_in_days:0 hz:18 lru_clock:5923291 config_file:/usr/local/redis/conf/sentinel.conf # Sentinel sentinel_masters:1 sentinel_tilt:0 sentinel_running_scripts:0 sentinel_scripts_queue_length:0 master0:name=zabbix,status=ok,address=192.168.126.128:6379,slaves=0,sentinels=1 127.0.0.1:26379>
##查看master状态：
127.0.0.1:6379> info # Replication role:master connected_slaves:1 min_slaves_good_slaves:1 slave0:ip=192.168.126.133,port=6379,state=online,offset=59413,lag=1 master_repl_offset:59556 repl_backlog_active:1 repl_backlog_size:1048576 repl_backlog_first_byte_offset:2 repl_backlog_histlen:59555
再slaves启动redis和sentinel
[root@agent133 redis]# ls
bin data logs sentinel
[root@agent133 redis]# cd bin/
[root@agent133 bin]# ls
redis.sh
[root@agent133 bin]# ./redis.sh start
start redis-server...runing
[root@agent133 bin]# netstat -ntlp | grep 6379
tcp 0 0 0.0.0.0:6379 0.0.0.0:* LISTEN 4282/redis-server *
tcp6 0 0 :::6379 :::* LISTEN 4282/redis-server *
[root@agent133 bin]# redis-sentinel /usr/local/redis/conf/sentinel.conf &
[1] 4288
[root@agent133 bin]# 4288:X 21 Dec 19:12:32.938 * Increased maximum number of open files to 10032 (it was originally set to 1024).
_._
_.-``__ ''-._
_.-`` `. `_. ''-._ Redis 3.0.5 (00000000/0) 64 bit
.-`` .-```. ```\/ _.,_ ''-._
( ' , .-` | `, ) Running in sentinel mode
|`-._`-...-` __...-.``-._|'` _.-'| Port: 26379
| `-._ `._ / _.-' | PID: 4288
`-._ `-._ `-./ _.-' _.-'
|`-._`-._ `-.__.-' _.-'_.-'|
| `-._`-._ _.-'_.-' | http://redis.io
`-._ `-._`-.__.-'_.-' _.-'
|`-._`-._ `-.__.-' _.-'_.-'|
| `-._`-._ _.-'_.-' |
`-._ `-._`-.__.-'_.-' _.-'
`-._ `-.__.-' _.-'
`-._ _.-'
`-.__.-'
4288:X 21 Dec 19:12:32.940 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
4288:X 21 Dec 19:12:32.940 # Sentinel runid is 17607179ad13102b1561dcd6a999cff732ac0f98
4288:X 21 Dec 19:12:32.940 # +monitor master zabbix 192.168.126.128 6379 quorum 2
4288:X 21 Dec 19:12:33.944 * +slave slave 192.168.126.133:6379 192.168.126.133 6379 @ zabbix 192.168.126.128 6379
4288:X 21 Dec 19:12:35.052 * +sentinel sentinel 192.168.126.128:26379 192.168.126.128 26379 @ zabbix 192.168.126.128 6379
[root@agent133 bin]#
#连接Sentinel
[root@agent133 bin]# redis-cli -p 26379 127.0.0.1:26379> info # Server redis_version:3.0.5 redis_git_sha1:00000000 redis_git_dirty:0 redis_build_id:e0daa82ba7583198 redis_mode:sentinel os:Linux 3.10.0-327.22.2.el7.x86_64 x86_64 arch_bits:64 multiplexing_api:epoll gcc_version:4.8.5 process_id:4288 run_id:17607179ad13102b1561dcd6a999cff732ac0f98 tcp_port:26379 uptime_in_seconds:77 uptime_in_days:0 hz:11 lru_clock:5923821 config_file:/usr/local/redis/conf/sentinel.conf # Sentinel sentinel_masters:1 sentinel_tilt:0 sentinel_running_scripts:0 sentinel_scripts_queue_length:0 master0:name=zabbix,status=ok,address=192.168.126.128:6379,slaves=1,sentinels=2 127.0.0.1:26379>
在master的monitor界面，可以看到slave上的Sentinel发来的握手信息
482318873.513009 [0 192.168.126.133:52522] "PING" 1482318873.596223 [0 192.168.126.133:52522] "PUBLISH" "__sentinel__:hello" "192.168.126.133,26379,17607179ad13102b1561dcd6a999cff732ac0f98,0,zabbix,192.168.126.128,6379,0"
监控slave的redis实例，与master的握手信息
[redis@agent133 Desktop]$ redis-cli -p 6379 -a redis 127.0.0.1:6379> monitor OK 1482318949.276759 [0 192.168.126.133:49624] "PING" 1482318949.470154 [0 192.168.126.128:6379] "PUBLISH" "__sentinel__:hello" "192.168.126.133,26379,17607179ad13102b1561dcd6a999cff732ac0f98,0,zabbix,192.168.126.128,6379,0" 1482318949.822874 [0 192.168.126.128:42838] "PING" 1482318950.128768 [0 192.168.126.128:6379] "PUBLISH" "__sentinel__:hello" "192.168.126.128,26379,b4354571b53ffdbc7369913f3c2c87a31f2a22a4,0,zabbix,192.168.126.128,6379,0" 1482318950.300715 [0 192.168.126.133:49624] "PING" 1482318950.740239 [0 192.168.126.133:49624] "PUBLIS
#查看slave状态
[redis@agent133 Desktop]$ redis-cli -p 6379 -a redis 127.0.0.1:6379> info # Replication role:slave master_host:192.168.126.128 master_port:6379 master_link_status:up master_last_io_seconds_ago:1 master_sync_in_progress:0 slave_repl_offset:43672 slave_priority:90 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
在master上，添加键
localhost:6379> set name donald OK localhost:6379> get name "donald" localhost:6379>
在slaves，我们可以看到
127.0.0.1:6379> get name "donald" 127.0.0.1:6379>
在master上连接sentinel，查看master状态
127.0.0.1:26379> sentinel masters
1) 1) "name"
2) "zabbix"
3) "ip"
4) "192.168.126.128"
5) "port"
6) "6379"
7) "runid"
8) "239033187f3fd756c470f7f31b5e49efbf7c603d"
9) "flags"
10) "master"
11) "pending-commands"
12) "0"
13) "last-ping-sent"
14) "0"
15) "last-ok-ping-reply"
16) "264"
17) "last-ping-reply"
18) "264"
19) "down-after-milliseconds"
20) "30000"
21) "info-refresh"
22) "1861"
23) "role-reported"
24) "master"
25) "role-reported-time"
26) "2472617"
27) "config-epoch"
28) "0"
29) "num-slaves"
30) "2"
31) "num-other-sentinels"
32) "1"
33) "quorum"
34) "2"
35) "failover-timeout"
36) "180000"
37) "parallel-syncs"
38) "1"
#在128 Master 查看slave状态
127.0.0.1:26379> sentinel slaves zabbix
1) 1) "name"
2) "192.168.126.138:6379"
3) "ip"
4) "192.168.126.138"
5) "port"
6) "6379"
7) "runid"
8) "de9d33c23dc969932098503a28d7ac2cf2e67df6"
9) "flags"
10) "slave"
11) "pending-commands"
12) "0"
13) "last-ping-sent"
14) "0"
15) "last-ok-ping-reply"
16) "21"
17) "last-ping-reply"
18) "21"
19) "down-after-milliseconds"
20) "30000"
21) "info-refresh"
22) "7680"
23) "role-reported"
24) "slave"
25) "role-reported-time"
26) "198553"
27) "master-link-down-time"
28) "0"
29) "master-link-status"
30) "ok"
31) "master-host"
32) "192.168.126.128"
33) "master-port"
34) "6379"
35) "slave-priority"
36) "100"
37) "slave-repl-offset"
38) "119118"
2) 1) "name"
2) "192.168.126.133:6379"
3) "ip"
4) "192.168.126.133"
5) "port"
6) "6379"
7) "runid"
8) "47c588eabdc0ec1fe29d40be35b612ac82980b44"
9) "flags"
10) "slave"
11) "pending-commands"
12) "0"
13) "last-ping-sent"
14) "0"
15) "last-ok-ping-reply"
16) "21"
17) "last-ping-reply"
18) "21"
19) "down-after-milliseconds"
20) "30000"
21) "info-refresh"
22) "7679"
23) "role-reported"
24) "slave"
25) "role-reported-time"
26) "881369"
27) "master-link-down-time"
28) "0"
29) "master-link-status"
30) "ok"
31) "master-host"
32) "192.168.126.128"
33) "master-port"
34) "6379"
35) "slave-priority"
36) "90"
37) "slave-repl-offset"
38) "119118"
127.0.0.1:26379>
##当我们关闭138 slave redis实例时，master的sentinel会有相应的信息
127.0.0.1:26379> 7365:X 21 Dec 19:28:33.155 # +sdown slave 192.168.126.138:6379 192.168.126.138 6379 @ zabbix 192.168.126.128 6379 7365:X 21 Dec 19:28:52.068 * +reboot slave 192.168.126.138:6379 192.168.126.138 6379 @ zabbix 192.168.126.128 6379 7365:X 21 Dec 19:28:52.134 # -sdown slave 192.168.126.138:6379 192.168.126.138 6379 @ zabbix 192.168.126.128 6379
在138上连接sentinel，查看状态：
# Server redis_version:3.0.5 redis_git_sha1:00000000 redis_git_dirty:0 redis_build_id:e0daa82ba7583198 redis_mode:sentinel os:Linux 3.10.0-327.22.2.el7.x86_64 x86_64 arch_bits:64 multiplexing_api:epoll gcc_version:4.8.5 process_id:4847 run_id:6183fe493327f4eff1d0d4971fce11afecc96408 tcp_port:26379 uptime_in_seconds:160 uptime_in_days:0 hz:11 lru_clock:5925146 config_file:/usr/local/redis/conf/sentinel.conf # Sentinel sentinel_masters:1 sentinel_tilt:0 sentinel_running_scripts:0 sentinel_scripts_queue_length:0 master0:name=zabbix,status=ok,address=192.168.126.128:6379,slaves=2,sentinels=3 127.0.0.1:26379>
可以看出slaves为2,sentinels为3
现在我们来测试一下HA，关闭Master
localhost:6379> shutdown not connected>
在128上sentinel显示选举master和更新配置信息
127.0.0.1:26379> 7365:X 21 Dec 19:33:16.433 * +sentinel sentinel 192.168.126.138:26379 192.168.126.138 26379 @ zabbix 192.168.126.128 6379 7365:X 21 Dec 19:41:12.576 # +sdown master zabbix 192.168.126.128 6379 7365:X 21 Dec 19:41:12.655 # +new-epoch 1 ##选择master 7365:X 21 Dec 19:41:12.657 # +vote-for-leader 6183fe493327f4eff1d0d4971fce11afecc96408 1 7365:X 21 Dec 19:41:12.661 # +odown master zabbix 192.168.126.128 6379 #quorum 3/2 7365:X 21 Dec 19:41:12.661 # Next failover delay: I will not start a failover before Wed Dec 21 19:47:13 2016 ##更新slave 138配置 7365:X 21 Dec 19:41:13.762 # +config-update-from sentinel 192.168.126.138:26379 192.168.126.138 26379 @ zabbix 192.168.126.128 6379 ##将133切换为Master，128切换为slave，由于133的优先级为90,138优先级为100，所以选举133为master 7365:X 21 Dec 19:41:13.762 # +switch-master zabbix 192.168.126.128 6379 192.168.126.133 6379 7365:X 21 Dec 19:41:13.762 * +slave slave 192.168.126.138:6379 192.168.126.138 6379 @ zabbix 192.168.126.133 6379 7365:X 21 Dec 19:41:13.762 * +slave slave 192.168.126.128:6379 192.168.126.128 6379 @ zabbix 192.168.126.133 6379
在133，查看sever信息：
[redis@agent133 Desktop]$ redis-cli -p 6379 -a redis # Replication role:master connected_slaves:1 slave0:ip=192.168.126.138,port=6379,state=online,offset=65952,lag=0 master_repl_offset:65952 repl_backlog_active:1 repl_backlog_size:1048576 repl_backlog_first_byte_offset:2 repl_backlog_histlen:65951 db0:keys=1,expires=0,avg_ttl=0 127.0.0.1:6379>
128重启redis时，sentinel显示convert-to-slave
7365:X 21 Dec 19:45:55.555 * +convert-to-slave slave 192.168.126.128:6379 192.168.126.128 6379 @ zabbix 192.168.126.133 6379
在133上查看sentinel master与slaves状态
127.0.0.1:26379>
127.0.0.1:26379> sentinel masters
1) 1) "name"
2) "zabbix"
3) "ip"
4) "192.168.126.133"
5) "port"
6) "6379"
7) "runid"
8) "47c588eabdc0ec1fe29d40be35b612ac82980b44"
9) "flags"
10) "master"
11) "pending-commands"
12) "0"
13) "last-ping-sent"
14) "0"
15) "last-ok-ping-reply"
16) "288"
17) "last-ping-reply"
18) "288"
19) "down-after-milliseconds"
20) "30000"
21) "info-refresh"
22) "4219"
23) "role-reported"
24) "master"
25) "role-reported-time"
26) "546706"
27) "config-epoch"
28) "1"
29) "num-slaves"
30) "2"
31) "num-other-sentinels"
32) "2"
33) "quorum"
34) "2"
35) "failover-timeout"
36) "180000"
37) "parallel-syncs"
38) "1"
127.0.0.1:26379> sentinel slaves zabbix
1) 1) "name"
2) "192.168.126.128:6379"
3) "ip"
4) "192.168.126.128"
5) "port"
6) "6379"
7) "runid"
8) "71c8aab6f676f7d3e177a9c6321fd91a0d47fef6"
9) "flags"
10) "slave"
11) "pending-commands"
12) "0"
13) "last-ping-sent"
14) "0"
15) "last-ok-ping-reply"
16) "610"
17) "last-ping-reply"
18) "610"
19) "down-after-milliseconds"
20) "30000"
21) "info-refresh"
22) "5103"
23) "role-reported"
24) "slave"
25) "role-reported-time"
26) "286309"
27) "master-link-down-time"
28) "1482321036000"
29) "master-link-status"
30) "err"
31) "master-host"
32) "192.168.126.133"
33) "master-port"
34) "6379"
35) "slave-priority"
36) "100"
37) "slave-repl-offset"
38) "1"
2) 1) "name"
2) "192.168.126.138:6379"
3) "ip"
4) "192.168.126.138"
5) "port"
6) "6379"
7) "runid"
8) "0397cb460b84ca7df4650483ae8707bda53c2ddc"
9) "flags"
10) "slave"
11) "pending-commands"
12) "0"
13) "last-ping-sent"
14) "0"
15) "last-ok-ping-reply"
16) "582"
17) "last-ping-reply"
18) "582"
19) "down-after-milliseconds"
20) "30000"
21) "info-refresh"
22) "5661"
23) "role-reported"
24) "slave"
25) "role-reported-time"
26) "568112"
27) "master-link-down-time"
28) "0"
29) "master-link-status"
30) "ok"
31) "master-host"
32) "192.168.126.133"
33) "master-port"
34) "6379"
35) "slave-priority"
36) "100"
37) "slave-repl-offset"
38) "117625"
127.0.0.1:26379>
可以看到133被选举为master，128与138为slave
查看138的redis配置文件redis.conf,Master已经被修改
slaveof 192.168.126.133 6379
查看138的redis配置文件sentinel已经被修改
sentinel config-epoch zabbix 1 sentinel leader-epoch zabbix 1 sentinel known-slave zabbix 192.168.126.138 6379 # Generated by CONFIG REWRITE sentinel known-slave zabbix 192.168.126.128 6379 sentinel known-sentinel zabbix 192.168.126.133 26379 17607179ad13102b1561dcd6a999cff732ac0f98 sentinel known-sentinel zabbix 192.168.126.128 26379 b4354571b53ffdbc7369913f3c2c87a31f2a22a4 sentinel current-epoch 1
查看128与133的配置文件，也相应的修改。
133的slaveof配置被擦除
总结：
redis的主从与mysql的主从有点类似，都要配置slave的Master，sentinel类与Hadoop HA环境下的Zookeeper的作用，当集群中master宕机时，sentinel通过GrossIP协议选择出Master，并修改相应的redis.conf,与sentinel.conf配置文件。