一、Redis和Keepalived安装
1、 以下步骤在121和122上均要进行一遍
2、 以root用户登录,
cd /usr/local
2、命令:mkdir ms40 新建ms40目录
3、cd ms40
4、mkdir redis && cd redis && mkdir log && mkdir data然后切回ms40目录
5、mkdir keepalived
6、上传文件redis-2.6.14.tar.gz至redis目录
上传文件keepalived-1.2.7.tar.gz至keepalived目录
7、安装redis
1)cd redis
2)tar zxvf redis-2.6.14.tar.gz
3)cd redis-2.6.14
4)make
5)cd src
6)cp redis-benchmark redis-cli redis-server /usr/bin/
7)切回至ms40目录
8、安装keepalived
1)cd keepalived
2)tar zxvf keepalived-1.2.7.tar.gz
3)yum install popt-devel
4)yum -y install openssl-devel
5)cd keepalived-1.2.7
6)./configure
7)make && make install
二、Keepalived配置
1、 转移keepalived的配置文件
1) cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/ 2) cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/ 3) mkdir /etc/keepalived
4) cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/ 5) cp /usr/local/sbin/keepalived /usr/sbin/
三、Mater配置(10.25.174.121)
1、 从附件的Master文件夹中获取scripts文件夹和keepalived.conf覆盖至目录 /etc/keepalived目录下
2、给脚本加上可执行权限:chmod +x /etc/keepalived/scripts/*.sh
3、备份/usr/local/ms40/redis/redis-2.6.14目录下的redis.conf文件
4、从附件的Master文件夹中获取redis.conf文件覆盖至上述目录中
四、Slave配置(10.25.174.122)
1、 从附件的Slave文件夹中获取scripts文件夹和keepalived.conf覆盖至目录 /etc/keepalived目录下
2、给脚本加上可执行权限:chmod +x /etc/keepalived/scripts/*.sh
3、备份/usr/local/ms40/redis/redis-2.6.14目录下的redis.conf文件
4、从附件的Master文件夹中获取redis.conf文件覆盖至上述目录中
五、启动
1、 启动121上的redis
1)cd /
2)cd /usr/local/ms40/redis/redis-2.6.14
3)src/redis-server
2、启动122上的redis
1)cd /
2)cd /usr/local/ms40/redis/redis-2.6.14
3)src/redis-server
3、启动121上的keepalived
1)cd /
2)service keepalived start
4、启动122上的keepalived
1)cd /
2)service keepalived start
六、验证
1、运行-cmd
Ping 10.25.174.200 看是否能够ping通
2、 运行-cmd
telnet 10.25.174.200 6379 是否能通
3、 使用sshclient连接至121或者122,使用root用户
cd /usr/local/ms40/redis/redis-2.6.14
src/redis-cli –h 10.25.174.200
set name “test”
get name
看看结果是否为test
如果是则 del test
六、安装Redis过程中涉及的一些问题
1、GCC的问题
make[2]: cc: Command not found
make[1]: *** [adlist.o] Error 127
make[1]: Leaving directory `/usr/local/redis-2.6.16/src'
make: *** [all] Error 2
原因:没安装gcc,执行命令安装:yum install gcc-c++
2、内存分配器的问题(重视) make[1]: Entering directory `/usr/local/redis-2.6.16/src'
CC adlist.o
In file included from adlist.c:34:
zmalloc.h:50:31: error: jemalloc/jemalloc.h: No such file or directory
zmalloc.h:55:2: error: #error "Newer version of jemalloc required"
make[1]: *** [adlist.o] Error 1
make[1]: Leaving directory `/usr/local/redis-2.6.16/src'
make: *** [all] Error 2
原因:查看redis的源码 src/zmalloc.c可以看到如下代码:
#if defined(USE_TCMALLOC)
#define malloc(size) tc_malloc(size)
#define calloc(count,size) tc_calloc(count,size)
#define realloc(ptr,size) tc_realloc(ptr,size)
#define free(ptr) tc_free(ptr)
#elif defined(USE_JEMALLOC)
#define malloc(size) je_malloc(size)
#define calloc(count,size) je_calloc(count,size)
#define realloc(ptr,size) je_realloc(ptr,size)
#define free(ptr) je_free(ptr)
可以看到源码中首先会判断系统中是否存在tcmalloc内存分配器,如果没有,则使用jemalloc内存分配器,如果连jemalloc分配器也没有找到,就会报错了。
本次现网部署Redis后,因为没有jemalloc分配器,导致碎片率达到了1.59,redis的内存占用率也就是实际内存占用的1.59倍,这个数据量是非常恐怖的,对内存资源是个相当大的损耗。
在现网环境的linux系统中,可能没有预先安装Jemalloc分配器,需要手动安装。
1、wget /download/jemalloc/jemalloc-3.2.0.tar.bz2
2、tar jxf jemalloc-3.2.0.tar.bz2(tar.bz2的压缩格式使用 tar jxf 解压)
3、cd jemalloc-3.2.0
4、./configure
5、make && make install
6、ldconfig
过程完成后,在切回到redis-2.6.14目录中,重新执行make命令
当然如果不想使用jemalloc分配器,可以强制使用如下命令来安装redis:
make MALLOC=libc(libc是默认的内存分配器,不过经过验证,碎片率是最高的)
经现网验证:
1) 使用libc内存分配器的话,内存碎片率可以达到1.6左右
2) 但是使用jemalloc,碎片率一般在1.1以内
3) 对于tcmalloc,和jemalloc的结果差不多,但是因为redis暂时还没有集成tcmalloc,
所以需要另外来安装,过程详见:
七、安装Keepalived过程中涉及的一些问题
1、虚拟网卡sit0的问题 Keepalived安装完成后,在启动时报了如下的异常:
Oct 18 00:24:43 localhost Keepalived[6866]: Starting VRRP child process, pid=6868
Oct 18 00:24:43 localhost Keepalived_vrrp[6868]: No such interface, sit0
使用ip a命令查看网卡信息如下:
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
link/ether 00:50:56:ba:67:6e brd ff:ff:ff:ff:ff:ff inet 10.25.174.122/24 brd 10.25.174.255 scope global eth0 inet6 fe80::250:56ff:feba:676e/64 scope link valid_lft forever preferred_lft forever
3: sit0: <NOARP> mtu 1480 qdisc noop
link/sit 0.0.0.0 brd 0.0.0.0
网上对于sit0的描述如下:
点了很多网页来解决该问题,后来在朱万骏的帮助下,在/etc/modprobe.conf文件增加如下两行配置:
alias ipv6 off
alias net-pf-10 off
然后reboot重启服务器
2、nc命令的问题
家里测试环境(79.78、79.79)没有nc命令(类似windows下的telnet)
1) wget
2) tar zxvf netcat-0.7.1.tar.gz
3) ./configure
4) make && make install
3、检测脚本的问题
因家里在压测的时候,服务器没有nc命令,所以在检测脚本redis_check.sh中使用的是ping命令来检测redis是否还活着。但是因为在大并发情况下,ping命令会被拥堵,由此可能导致redis主备进行切换
原redis_check.sh:
#!/bin/bash
ALIVE=`/usr/bin/redis-cli PING`
if [ "$ALIVE" == "PONG" ]; then
echo $ALIVE
exit 0
else
echo $ALIVE
exit 1
fi
现redis_check.sh:
#!/bin/bash
nc -w 0 127.0.0.1 6379 && exit 0 || exit 1
4、keepalived.conf问题
Keepalived.conf中有运行监测脚本redis_check.sh的配置:
vrrp_script chk_redis {
script "/etc/keepalived/scripts/redis_check.sh" interval 1
}
变量interval 表示执行监测脚本的时间间隔:1秒执行一次确实没有必要。
5秒执行一次即可。
第二篇:通过Keepalived实现Redis Failover自动故障切换功能
通过Keepalived实现Redis Failover自动故障切换功能
详细可参考http://heylinux.com/archives/1942.html
设计思路:
redis 主和 redis从 正常同步;
redis主keepalived 启动,执行redis_master.sh脚本,vip在自己身上;
redis 从keepalived 启动,执行redis_slave.sh脚本;
redis主服务关闭,则redis主执行redis_fault.sh脚本, vip落在redis 从上,redis从执行redis-_master.sh脚本,变成主;
redis主服务开启,则redis主执行redis_slave.sh脚本变成从,vip还在redis 从上,还是主; redis从服务关闭,则redis从执行redis_fault.sh脚本, vip落在redis主上,redis主执行redis-_master.sh脚本,变成主;
redis从服务开启,则redis从执行redis_slave.sh脚本变成从, vip还在redis主上,redis主继续做主,此时为redis初试主从状态;
环境:
192.168.1.235 redis
192.168.1.236 redis-slave
192.168.1.237 vip
一:安装keepalived
(redis和redis-slave两台服务器都安装)
yum -y install ipvsadm
wget /software/keepalived-1.2.2.tar.gz
tar -zxvf keepalived-1.2.2.tar.gz
cd keepalived-1.2.2
./configure
configure时若出现以下结果:
不推荐使用yum install -y kernel-devel安装 安装完成后建立一下链接在配置:
ln -s /usr/src/kernels/2.6.18-194.el5-i686/ /usr/src/linux/
上述过程完毕后,在进行configure:
make
make install
cp /usr/local/etc/rc.d/init.d/keepalived /etc/init.d/
chmod 755 /etc/init.d/keepalived
cp /usr/local/sbin/keepalived /usr/sbin/
cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/
#运行 由于keepalived配置文件不是在启动时一次性加载并读取完成的,所以必须是完整路径,可以根据log判断是否加载了正确的配置文件
keepalived –f /usr/local/etc/keepalived/keepalived.conf
运行过程可以查看log:
tail -f /var/log/message
二:安装redis
(redis和redis-slave两台服务器都安装)
tar -zxvf redis-2.4.17.tar.gz
cd redis-2.4.17
./configure
make
make install
redis-slve只需注意一点
[root@redis bin]# pwd
/usr/local/bin
[root@redis bin]# vim redis.conf
116 slaveof 192.168.1.235 6379
三:通过Keepalived实现Redis Failover自动故障切换
修改Master和Slave的/etc/hosts文件
[root@redis rc.d]# cat /etc/hosts
192.168.1.235 redis
192.168.1.236 redis-slave
Master上是
[root@redis rc.d]# cat /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=redis
Slave上是
[root@redis-slave linux]# cat /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=redis-slave
修改完主机名重启机器生效
默认安装完成keepalived之后是没有配置文件的,因此我们需要手动创建: 首先,在Master上创建如下配置文件:
[root@redis linux]# vim /etc/keepalived/keepalived.conf
global_defs {
notification_email {
xiesongmeng@xlhtol.com
}
notification_email_from keepalived@redis
router_id redis
}
vrrp_script chk_redis {
script "/etc/keepalived/scripts/redis_check.sh" interval 1
}
vrrp_instance mes_Redis {
state MASTER
interface eth0
garp_master_delay 10
smtp_alert
virtual_router_id 3
priority 100
nopreempt
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.1.237
}
track_script {
chk_redis
}
notify_master /etc/keepalived/scripts/redis_master.sh notify_backup /etc/keepalived/scripts/redis_slave.sh notify_fault /etc/keepalived/scripts/redis_fault.sh notify_stop /etc/keepalived/scripts/redis_stop.sh }
然后,在Slave上创建如下配置文件:
[root@redis-slave linux]# vim /etc/keepalived/keepalived.conf global_defs {
notification_email {
xiesongmeng@xlhtol.com
}
notification_email_from keepalived@redis-slave router_id redis-salve
}
vrrp_script chk_redis {
script "/etc/keepalived/scripts/redis_check.sh" interval 1
}
vrrp_instance mes_Redis {
state BACKUP
interface eth0
garp_master_delay 10
smtp_alert
virtual_router_id 3
priority 90
nopreempt
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.1.237
}
track_script {
chk_redis
}
notify_master /etc/keepalived/scripts/redis_master.sh notify_backup /etc/keepalived/scripts/redis_slave.sh notify_fault /etc/keepalived/scripts/redis_fault.sh notify_stop /etc/keepalived/scripts/redis_stop.sh }
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
编写以下负责运作的关键脚本:
notify_master /etc/keepalived/scripts/redis_master.sh
notify_backup /etc/keepalived/scripts/redis_slave.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呼叫:
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Keepalived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: vim /etc/keepalived/scripts/redis_master.sh
#!/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 192.168.1.236 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
vim /etc/keepalived/scripts/redis_slave.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 192.168.1.236 6379 >> $LOGFILE 2>&1
接着,在Redis Slave上创建notity_master与notify_backup脚本:
vim /etc/keepalived/scripts/redis_master.sh
#!/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 192.168.1.235 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
vim /etc/keepalived/scripts/redis_slave.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 192.168.1.235 6379 >> $LOGFILE 2>&1
然后在Master与Slave创建如下相同的脚本:
vim /etc/keepalived/scripts/redis_fault.sh
#!/bin/bash
LOGFILE=/var/log/keepalived-redis-state.log
echo "[fault]" >> $LOGFILE
date >> $LOGFILE
vim /etc/keepalived/scripts/redis_stop.sh
#!/bin/bash
LOGFILE=/var/log/keepalived-redis-state.log
echo "[stop]" >> $LOGFILE
date >> $LOGFILE
在Master与Slave给脚本都加上可执行权限:
chmod +x /etc/keepalived/scripts/*.sh
脚本创建完成以后,我们开始按照如下流程进行测试:
1.启动Master上的Redis
[root@redis bin]# pwd
/usr/local/bin
[root@redis bin]# ./redis-server redis.conf
2.启动Slave上的Redis
[root@redis bin]# pwd
/usr/local/bin
[root@redis bin]# ./redis-server redis.conf
3.启动Master上的Keepalived
/etc/init.d/keepalived start
4.启动Slave上的Keepalived
/etc/init.d/keepalived start
5.尝试通过VIP连接Redis:
[root@redis bin]#pwd
/usr/local/bin
[root@redis bin]# ./redis-cli -h 192.168.1.237 info
role:master
slave0:192.168.1.236,6379,online
连接成功,Slave也连接上来了
6.尝试插入一些数据:
[root@redis bin]# ./redis-cli -h 192.168.1.237 SET Hello Redis 从VIP读取数据
[root@redis bin]# ./redis-cli -h 192.168.1.237 GET Hello "Redis"
从Master读取数据
[root@redis bin]# ./redis-cli -h 192.168.1.235 GET Hello
"Redis"
从Slave读取数据
[root@redis-slave bin]# ./redis-cli -h 192.168.1.235 GET Hello
"Redis"
下面,模拟故障产生:
将Master上的Redis进程杀死:
[root@redis bin]# ./redis-cli shutdown
查看Master上的Keepalived日志
[root@redis scripts]# tail /var/log/keepalived-redis-state.log
[fault]
Thu Sep 27 08:29:01 CST 2012
同时Slave上的日志显示:
[root@redis-slave scripts]# tail /var/log/keepalived-redis-state.log
[master]
Thu Nov 15 12:06:04 CST 2012
Being master....
Run SLAVEOF cmd ...
OK
Run SLAVEOF NO ONE cmd ...
OK
然后我们可以发现,Slave已经接管服务,并且担任Master的角色了。 ./redis-cli -h 192.168.1.237 info
./redis-cli -h 192.168.1.236 info
role:master
然后我们恢复Master的Redis进程
主变成slave
然后把236redis停掉
235恢复主的角色,在把236redis开启
恢复235是主,236是备
自动切换成功!