Redis 安装，主从配置及Sentinel配置自动Failover

1、安装redis

首页地址：http://redis.io/

下载地址：http://download.redis.io/ 下载最新的源码包

tar -zxvf redis-stable.tar.gz -C /apps/product/
cd  /apps/product/redis-stable/
make MALLOC=libc
make install

2、运行

加载配置文件并后台运行

redis-server /apps/product/redis-stable/redis.conf &

#redis-cli （命令行工具）

3、测试

# redis-benchmark --help 获取帮助信息，其中包含压力测试命令样例

实际测试举例

[root@localhost~]# redis-benchmark -t set -c 20 -n 1000000 -r 100000000
====== SET ======
 1000000 requests completed in 8.92 seconds
 20 parallel clients
 3 bytes payload
 keep alive: 1
100.00% <= 0 milliseconds
112095.06 requests per second　　

4、主从配置及测试:

主	gc-redis1	10.10.10.15	6379
从	gc-redis2	10.10.10.16	6379
从	gc-redis3	10.10.10.17	6379

#主服务器(10.15)上做如下配置，其他默认即可：

[root@gc-redis1 redis-stable]# vim /apps/product/redis-stable/redis.conf
masterauth "xxoo"
requirepass "xxoo"

#从服务器上(10.16,10.17)做如下配置，其他默认即可：

[root@gc-redis2 redis-stable]# vim /apps/product/redis-stable/redis.conf
slaveof 10.10.10.15 6379
masterauth "xxoo"
requirepass "xxoo"

[root@gc-redis3 redis-stable]# vim /apps/product/redis-stable/redis.conf
slaveof 10.10.10.15 6379
masterauth "xxoo"
requirepass "xxoo"

#启动主、从redis服务：

redis-server /apps/product/redis-stable/redis.conf &

#主服务器显示信息：

[13997] 03 Nov 09:57:21.045 * Slave ask for synchronization
[13997] 03 Nov 09:57:21.045 * Starting BGSAVE for SYNC
[13997] 03 Nov 09:57:21.046 * Background saving started by pid 14002
[14002] 03 Nov 09:57:21.058 * DB saved on disk
[14002] 03 Nov 09:57:21.059 * RDB: 0 MB of memory used by copy-on-write
[13997] 03 Nov 09:57:21.070 * Background saving terminated with success
[13997] 03 Nov 09:57:21.070 * Synchronization with slave succeeded

#从服务器显示信息：

　 [3496] 03 Nov 09:56:41.953 * Connecting to MASTER...
  [3496] 03 Nov 09:56:41.953 * MASTER <-> SLAVE sync started
  [3496] 03 Nov 09:56:41.954 * Non blocking connect for SYNC fired the event.
  [3496] 03 Nov 09:56:41.954 * Master replied to PING, replication can continue...
  [3496] 03 Nov 09:56:42.055 * MASTER <-> SLAVE sync: receiving 18 bytes from master
  [3496] 03 Nov 09:56:42.055 * MASTER <-> SLAVE sync: Loading DB in memory
  [3496] 03 Nov 09:56:42.055 * MASTER <-> SLAVE sync: Finished with success
  [3499] 03 Nov 09:56:42.056 * SYNC append only file rewrite performed
  [3499] 03 Nov 09:56:42.057 * AOF rewrite: 0 MB of memory used by copy-on-write
  [3496] 03 Nov 09:56:42.057 * Background append only file rewriting started by pid 3499
  [3496] 03 Nov 09:56:42.154 * Background AOF rewrite terminated with success
  [3496] 03 Nov 09:56:42.154 * Parent diff successfully flushed to the rewritten AOF (0 bytes)
  [3496] 03 Nov 09:56:42.154 * Background AOF rewrite finished successfully

#主服务器查看主从信息

[root@gc-redis1 ~]# redis-cli -h 127.0.0.1 -a xxoo info replication
# Replication
role:master
connected_slaves:2
slave0:ip=10.10.10.16,port=6379,state=online,offset=168812144,lag=1
slave1:ip=10.10.10.17,port=6379,state=online,offset=168812144,lag=0
master_repl_offset:168812281
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:167763706
repl_backlog_histlen:1048576

#从服务器查看主从信息

[root@gc-redis2 ~]# redis-cli -h 127.0.0.1 -a xxoo info replication
# Replication
role:slave
master_host:10.10.10.15
master_port:6379
master_link_status:up
master_last_io_seconds_ago:0
master_sync_in_progress:0
slave_repl_offset:168809239
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

#写同步测试

 #主服务器 

[root@gc-redis1 ~]# redis-cli -h 127.0.0.1 -a redispass
 
redis 127.0.0.1:6379> set a 123
OK
redis 127.0.0.1:6379> get a
"123"

#从服务器

[root@gc-redis2~]# redis-cli -h 127.0.0.1 -a xxoo
redis 127.0.0.1:6379> get a
 "123"
[root@gc-redis3~]# redis-cli -h 127.0.0.1 -a xxoo
redis 127.0.0.1:6379> get a
 "123"
 
 redis 127.0.0.1:6379> set b 234
 (error) READONLY You can't write against a read only slave. （开起了只读模式，所以从将不能写入数据，可以保证数据只从主服务器同步至从服务器）

#故障测试

#从服务器宕机将自动从主服务器的主从关系中解除

#主服务器宕机，从服务器显示，并且不能自动切换

[15932] 03 Nov 09:46:25.465 * Connecting to MASTER...
[15932] 03 Nov 09:46:25.465 * MASTER <-> SLAVE sync started
[15932] 03 Nov 09:46:25.466 # Error condition on socket for SYNC: Connection refused

5、Redis sentinel配置

主页地址：http://redis.io/topics/sentinel

sentinel主要功能就是为Redis M-S(master,slaves)集群提供了

1)master存活检测

2)集群中M-S服务监控

3) 自动故障转移,M-S角色转换等能力,从一个方面说是提高了redis集群的可用性.

#添加并编辑配置文件/etc/sentinel.conf，新增内容如下，也可在安装文件中负责sentinel配置文件并作适当修改：

[root@gc-redis1 ~]# vim /apps/product/redis-stable/sentinel.conf
port 26379
sentinel monitor mymaster 10.10.10.15 6379 2
sentinel down-after-milliseconds mymaster 3000
sentinel failover-timeout mymaster 20000
sentinel auth-pass mymaster xxoo
sentinel config-epoch mymaster 2
sentinel leader-epoch mymaster 2
-----------------------------------------------------------------------------------------------

[root@gc-redis2 ~]# vim /apps/product/redis-stable/sentinel.conf
port 26380
sentinel monitor mymaster 10.10.10.15 6379 2
sentinel down-after-milliseconds mymaster 3000
sentinel failover-timeout mymaster 20000
sentinel auth-pass mymaster xxoo
sentinel config-epoch mymaster 2
sentinel leader-epoch mymaster 2
----------------------------------------------------------------------------------------------
[root@gc-redis3 ~]# vim /apps/product/redis-stable/sentinel.conf
port 26381
sentinel monitor mymaster 10.10.10.15 6379 2
sentinel down-after-milliseconds mymaster 3000
sentinel failover-timeout mymaster 20000
sentinel auth-pass mymaster xxoo
sentinel config-epoch mymaster 2
sentinel leader-epoch mymaster 2　　

#在三个服务器中以sentinel模式启动redis-server

启动sentinel
 
[root@gc-redis1 ~]#redis-server /apps/product/redis-stable/sentinel.conf --sentinel &
[root@gc-redis2 ~]#redis-server /apps/product/redis-stable/sentinel.conf --sentinel &
[root@gc-redis3 ~]#redis-server /apps/product/redis-stable/sentinel.conf --sentinel &

#三台服务器sentinel输出：（注意每个机器输出对应的都是另外两台机器的IP）

#关掉主gc-redis1的redis-server服务

#将重新选举主服务器并重新配置连接到新的主服务器：

#查看主从关系：（gc-redis2为主，gc-redis3为从，如果gc-redis1重新启动，也将为从服务器加入到新的集群）

启动redis
redis-server /usr/local/redis-stable/redis.conf &
 
停止redis
redis-cli -a xxoo shutdown
 
启动sentinel
redis-server /usr/local/redis-stable/sentinel.conf --sentinel &
 
查看主备信息：
redis-cli -h 127.0.0.1 -p 6379 -a xxoo info replication

.

参考文档：http://mrcto.blog.51cto.com/1923168/1319542