本文装载自：http://abcve.com/redis-keepalived/
一：环境介绍
Master: 10.0.0.13
Slave: 10.0.0.14
Virtural IP Address (VIP): 10.0.0.15
二：设计思路：
当 Master 与 Slave 均运作正常时, Master负责服务，Slave负责Standby；
当 Master 挂掉，Slave 正常时, Slave接管服务，有写权限，同时关闭主从复制功能；
当 Master 恢复正常，则从Slave同步数据，同步数据之后关闭主从复制功能，恢复Master身份，同时Slave等待Master同步数据完成之后，恢复Slave身份。
三：安装配置前准备工作
在主服务器 10.0.0.13 上面做下面操作
echo “10.0.0.13 server1” >> /etc/hosts
echo “10.0.0.14 server2” >> /etc/hosts
在从服务器 172.16.206.28 上面做下面操作
echo “10.0.0.13 server1” >> /etc/hosts
echo “10.0.0.14 server2” >> /etc/hosts
四：主服务器配置redis
1．下载redis 版本3.2.11
wget http://download.redis.io/releases/redis-3.2.11.tar.gz
2．解压 tar -zxvf redis-3.2.11.tar.gz
3．cd redis-3.2.11
4．make && make install
5．cp redis.conf /etc/redis.conf
cd src/
cp redis-server redis-cli redis-benchmark redis-check-aofredis-check-dump /usr/local/bin
6．修改 /etc/redis.conf里面可以把daemonize no 修改为daemonize yes
目的是可以在后台执行redis-server。
7．init.d 启动脚本
vi /etc/init.d/redis-server
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
|
#!/usr/bin/env bash
#
# redis start up the redis server daemon
#
# chkconfig: 345 99 99
# description: redis service in /etc/init.d/redis
# chkconfig --add redis or chkconfig --list redis
# service redis start or service redis stop
# processname: redis-server
# config: /etc/redis.conf
PATH
=
/
usr
/
local
/
bin
:
/
sbin
:
/
usr
/
bin
:
/
bin
REDISPORT
=
6379
EXEC
=
/
usr
/
local
/
bin
/
redis
-
server
REDIS_CLI
=
/
usr
/
local
/
bin
/
redis
-
cli
PIDFILE
=
/
var
/
run
/
redis
.
pid
CONF
=
"/etc/redis.conf"
#make sure some dir exist
if
[
!
-
d
/
var
/
lib
/
redis
]
;
then
mkdir
-
p
/
var
/
lib
/
redis
mkdir
-
p
/
var
/
log
/
redis
fi
case
"$1"
in
status
)
ps
-
A
|
grep
redis
;
;
start
)
if
[
-
f
$
PIDFILE
]
then
echo
"$PIDFILE exists, process is already running or crashed"
else
echo
"Starting Redis server..."
$
EXEC
$
CONF
fi
if
[
"$?"
=
"0"
]
then
echo
"Redis is running..."
fi
;
;
stop
)
if
[
!
-
f
$
PIDFILE
]
then
echo
"$PIDFILE does not exist, process is not running"
else
PID
=
$
(
cat
$
PIDFILE
)
echo
"Stopping ..."
$
REDIS_CLI
-
p
$
REDISPORT
SHUTDOWN
while
[
-
x
$
{
PIDFILE
}
]
do
echo
"Waiting for Redis to shutdown ..."
sleep
1
done
echo
"Redis stopped"
fi
;
;
restart
|
force
-
reload
)
$
{
0
}
stop
$
{
0
}
start
;
;
*
)
echo
"Usage: /etc/init.d/redis {start|stop|restart|force-reload}"
>
&
2
exit
1
esac
|
chmod o+x /etc/init.d/redis-server
chkconfig –add redis-server
service redis-server start
五：从服务器配置redis
从服务器，配置一样，只不过 修改/etc/redis.conf 中
slaveof <masterip> <masterport>修改为
slaveof 10.0.0.13 6379
然后开启从服务器的redis服务。
start redis-server start
六：进行redis主从测试
#主服务器
redis-cli -p 6379 set hello world
#从服务器
redis-cli -p 6379 get hello
“world”
#主服务器
redis-cli -p 6379 set hello2 world2
#从服务器
redis-cli -p 6379 get hello2
“world2”
redis-cli -p 6379 set hello world
(error) READONLY You can’t write against a read only slave.
成功配置主从redis服务器，由于配置中有一条从服务器是只读的，所以从服务器没法设置数据，只可以读取数据。
七：安装和配置keepalived
1． wget http://www.keepalived.org/software/keepalived-1.3.5.tar.gz
tar -zxvf keepalived-1.3.5.tar.gz
cd keepalived-1.3.5
2． 安装openssl-devel和kernel-devel
yum install openssl-devel
yum install kernel-devel
ln -s /usr/src/kernels/2.6.32-696.10.1.el6.x86_64 /usr/src/linux
3． 配置编译安装
./configure–prefix=/usr/local/keepalived –with-kernel-dir=/usr/src/linux –enable-sha1
make && make install
4． 复制keepalived相关文件
cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/keepalived
cp /usr/local/keepalived/sbin/keepalived /usr/sbin/keepalived
cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/keepalived
mkdir /etc/keepalived
cp /usr/local/keepalived/etc/keepalived/samples/keepalived.conf.virtualhost
/etc/keepalived/keepalived.conf
八：修改配置文件和相关脚本
1． 在Master上创建配置文件
vi /etc/keepalived/keepalived.conf
! Configuration File for keepalived
vrrp_script chk_redis {
script "/etc/keepalived/scripts/redis_check.sh" ###监控脚本
interval 2 ###监控时间
}
#网卡需要注意，使用ifconfig查看一下当前活动网卡
vrrp_instance VI_1 {
state MASTER ###设置为MASTER
interface eth1 ###监控网卡
virtual_router_id 51
priority 100 ###权重值
authentication {
auth_type PASS ###加密
auth_pass 1111 ###密码
}
track_script {
chk_redis ###执行上面定义的chk_redis
}
virtual_ipaddress {
172.16.206.250 ######VIP
}
notify_master /etc/keepalived/scripts/redis_master.sh
notify_backup /etc/keepalived/scripts/redis_backup.sh
notify_fault /etc/keepalived/scripts/redis_fault.sh
notify_stop /etc/keepalived/scripts/redis_stop.sh
}
2．在Slave上创建如下配置文件
vim /etc/keepalived/keepalived.conf
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
|
!
Configuration
File
for
keepalived
vrrp_script
chk_redis
{
script
"/etc/keepalived/scripts/redis_check.sh"
###监控脚本
interval
2
###监控时间
}
#同样要注意网卡
vrrp_instance
VI_1
{
state
BACKUP
###设置为BACKUP
interface
eth1
###监控网卡
virtual_router_id
51
priority
10
###比MASTRE权重值低
authentication
{
auth_type
PASS
auth
_pass
1111
###密码与MASTRE相同
}
track_script
{
chk
_redis
###执行上面定义的chk_redis
}
virtual_ipaddress
{
10.0.0.15
####vip
}
notify_master
/
etc
/
keepalived
/
scripts
/
redis_master
.
sh
notify_backup
/
etc
/
keepalived
/
scripts
/
redis_backup
.
sh
notify
_fault
/
etc
/
keepalived
/
scripts
/
redis_fault
.
sh
notify
_stop
/
etc
/
keepalived
/
scripts
/
redis_stop
.
sh
}
|
3．在Master和Slave上创建监控Redis的脚本
$ mkdir /etc/keepalived/scripts
$ vim /etc/keepalived/scripts/redis_check.sh
#!/bin/bash
ALIVE
=
`
/
usr
/
local
/
bin
/
redis
-
cli
PING
`
if
[
"$ALIVE"
==
"PONG"
]
;
then
echo
$
ALIVE
exit
0
else
echo
$
ALIVE
exit
1
fi
4．编写关键脚本
notify_master /etc/keepalived/scripts/redis_master.sh
notify_backup /etc/keepalived/scripts/redis_backup.sh
notify_fault /etc/keepalived/scripts/redis_fault.sh
notify_stop /etc/keepalived/scripts/redis_stop.sh
因为Keepalived在转换状态时会依照状态来执行脚本：
当进入Master状态时会呼叫notify_master
当进入Backup状态时会呼叫notify_backup
当发现异常情况时进入Fault状态呼叫notify_fault
当程序终止时则呼叫notify_stop
首先，在Redis Master上创建notity_master与notify_backup脚本：
vi /etc/keepalived/scripts/redis_master.sh
1
2
3
4
5
6
7
8
9
10
11
12
13
14
|
#!/bin/bash
REDISCLI
=
"/usr/local/bin/redis-cli"
LOGFILE
=
"/var/log/keepalived-redis-state.log"
echo
"[master]"
>>
$
LOGFILE
date
>>
$
LOGFILE
echo
"Being master...."
>>
$
LOGFILE
2
>
&
1
echo
"Run SLAVEOF cmd ..."
>>
$
LOGFILE
$
REDISCLI
SLAVEOF
10.0.0.14
6379
>>
$
LOGFILE
2
>
&
1
sleep
10
#延迟10秒以后待数据同步完成后再取消同步状态
echo
"Run SLAVEOF NO ONE cmd ..."
>>
$
LOGFILE
$
REDISCLI
SLAVEOF
NO
ONE
>>
$
LOGFILE
2
>
&
1
|
vi /etc/keepalived/scripts/redis_backup.sh
|
|
#!/bin/bash
REDISCLI="/usr/local/bin/redis-cli"
LOGFILE="/var/log/keepalived-redis-state.log"
echo "[backup]" >> $LOGFILE
date >> $LOGFILE
echo "Being slave...." >> $LOGFILE 2>&1
sleep 15 #延迟15秒待数据被对方同步完成之后再切换主从角色
echo "Run SLAVEOF cmd ..." >> $LOGFILE
$REDISCLI SLAVEOF 192.168.1.sl 6379 >> $LOGFILE 2>&1
|
在Redis Slave上创建notity_master与notify_backup脚本：
vi /etc/keepalived/scripts/redis_master.sh
1
2
3
4
5
6
7
8
9
10
11
12
13
|
#!/bin/bash
REDISCLI
=
"/usr/local/bin/redis-cli"
LOGFILE
=
"/var/log/keepalived-redis-state.log"
echo
"[master]"
>>
$
LOGFILE
date
>>
$
LOGFILE
echo
"Being master...."
>>
$
LOGFILE
2
>
&
1
echo
"Run SLAVEOF cmd ..."
>>
$
LOGFILE
$
REDISCLI
SLAVEOF
10.0.0.13
6379
>>
$
LOGFILE
2
>
&
1
sleep
10
#延迟10秒以后待数据同步完成后再取消同步状态
echo
"Run SLAVEOF NO ONE cmd ..."
>>
$
LOGFILE
$
REDISCLI
SLAVEOF
NO
ONE
>>
$
LOGFILE
2
>
&
1
|
vi /etc/keepalived/scripts/redis_backup.sh
#!/bin/bash
REDISCLI
=
"/usr/local/bin/redis-cli"
LOGFILE
=
"/var/log/keepalived-redis-state.log"
echo
"[backup]"
>>
$
LOGFILE
date
>>
$
LOGFILE
echo
"Being slave...."
>>
$
LOGFILE
2
>
&
1
sleep
15
#延迟15秒待数据被对方同步完成之后再切换主从角色
echo
"Run SLAVEOF cmd ..."
>>
$
LOGFILE
$
REDISCLI
SLAVEOF
192.168.1.4
6379
>>
$
LOGFILE
2
>
&
1
然后在Master与Slave创建如下相同的脚本：
vi /etc/keepalived/scripts/redis_fault.sh
|
|
#!/bin/bash
LOGFILE
=
/
var
/
log
/
keepalived
-
redis
-
state
.
log
echo
"[fault]"
>>
$
LOGFILE
date
>>
$
LOGFILE
|
vi /etc/keepalived/scripts/redis_stop.sh
#!/bin/bash
LOGFILE
=
/
var
/
log
/
keepalived
-
redis
-
state
.
log
echo
"[stop]"
>>
$
LOGFILE
date
>>
$
LOGFIL
在主从服务器上面给脚本都加上可执行权限：
chmod +x /etc/keepalived/scripts/*.sh
九：相关功能测试
启动Master和slave上的Redis
service redis-server start
启动Master和slave上的Keepalived
/etc/init.d/keepalived start
尝试通过VIP连接Redis:
$ redis-cli -h 10.0.0.15 INFO
连接成功，可以看到主从机的信息，例如：
role:master
slave0:10.0.0.13,6379,online
尝试插入一些数据：
$ redis-cli -h 10.0.0.15 SET hello3 world3
OK
从VIP读取数据
$ redis-cli -h 10.0.0.15 GET hello3
“world3”
从Master读取数据
$ redis-cli -h 10.0.0.13 GET hello3
“world3”
从Slave读取数据
$ redis-cli -h 10.0.0.14 GET hello3
“world3”
将Master上的Redis进程杀死：
$ service redis-server stop
查看Master上的Keepalived日志
$ tail -f /var/log/keepalived-redis-state.log
[fault]
Fri Sep 8 19:16:28 CST 2017
同时Slave上的日志显示：
$ tail -f /var/log/keepalived-redis-state.log
[master]
Fri Sep 8 19:16:28 CST 2017
Being master….
Run SLAVEOF cmd …
OK Already connected to specified master
Run SLAVEOF NO ONE cmd …
OK
现在，Slave已经接管服务，并且拥有Master的角色
$ redis-cli -h 10.0.0.14 INFO
$ redis-cli -h 10.0.0.15 INFO
role:master
然后恢复Master的Redis进程
$ service redis-server start
查看Master上的Keepalived日志
$ tail -f /var/log/keepalived-redis-state.log
[master]
Fri Sep 8 19:16:32 CST 2017
Being master….
Run SLAVEOF cmd …
OK
Run SLAVEOF NO ONE cmd …
OK
同时Slave上的日志显示：
$ tail -f /var/log/keepalived-redis-state.log
[backup]
Fri Sep 8 19:16:32 CST 2017
Being slave….
Run SLAVEOF cmd …
OK
Master已经再次恢复了Master角色