参考资料:
背景
目前,Redis集群的官方方案还处在开发测试中,未集成到稳定版中。且目前官方开发中的Redis Cluster提供的功能尚不完善(可参考官方网站或),在生产环境中不推荐使用。通过调研发现市面上要实现采用单一的IP来访问,大多采用keepalived实现redis的双机热备作为过渡方案。
环境部署
环境介绍: Master: 192.168.1.218 redis,keepalived Slave: 192.168.1.219 redis,keepalived Virtural IP Address (VIP): 192.168.1.220
设计思路:
两个redis server主从备份。提供redis 服务高可用;两个keepalived 服务主从备份,提供VIP 服务的高可用。
1)每台redis server分别有主,从两个配置文件(redis_master.conf,redis_slave.conf),通过启动脚本启动服务,启动脚本会检测这个redis集群中的其他服务器的角色,如果有master 服务存在,则以slave角色启动,否则将自己以master服务器启动;
2) keepalived 监控脚本,定时(频率:每秒一次)检测当前服务器是否获取集群VIP,如果获取集群VIP,则将本服务器上的redis服务器设置为master。同时将远端的其他redis服务器设置为slave;保证获取集群VIP的redis 服务器角色为master,其他的设置为slave。
3) keepalived 监控脚本,还会自动检测当前redis服务器是否正常,如果连续两次检测异常,则停掉本本机的keepalived服务,释放集群VIP,让去漂移到其他可以提供redis 服务的服务器上;
4)当 Master 与 Slave 均运作正常时,Master负责服务,Slave负责同步数据;当 Master 挂掉,Slave 正常时,Slave接管服务,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,于此同时Slave等待Master同步数据完成之后,恢复Slave身份。然后依次循环。
实施步骤:
----创建专用用户
useradd -g develop redisadmin echo Hisun@1125|passwd --stdin redisadmin
说明:以下部署过程都是在root(或具备sudo权限的账号)账户下进行。
----安装配置redis
1.下载redis源码
cd
wget
2.安装redis
tar -zxvf redis-2.8.3.tar.gz
cd redis-2.8.3
#reds的安装可以不用执行configure
make
#测试
make test
####在速度较慢的机器上执行make test可能出现下列错误,无影响
#*** [err]: Test replication partial resync: no backlog in tests/integration/replication-psync.tcl
3.配置redis
#创建redis主目录
mkdir -p /usr/local/redis-2.8.3/{bin,conf,logs}
cp -a -R -p src/redis-server /usr/local/redis-2.8.3/bin/
cp -a -R -p src/redis-cli /usr/local/redis-2.8.3/bin/
cp -a -R -p src/redis-benchmark /usr/local/redis-2.8.3/bin/
cp -a -R -p src/redis-sentinel /usr/local/redis-2.8.3/bin/
cp -a -R -p src/redis-check-dump /usr/local/redis-2.8.3/bin/
cp -a -R -p src/redis-check-aof /usr/local/redis-2.8.3/bin/
#创建redis启动脚本
vi /usr/local/redis-2.8.3/redis-start.sh
####以下为master上的配置,slave上的配置只需要修改对应的LOCALIP和REMOTEIP即可。
#!/bin/bash
REDISPATH=/usr/local/redis-2.8.3
REDISCLI=$REDISPATH/bin/redis-cli
LOGFILE=$REDISPATH/logs/redis-state.log
LOCALIP=192.168.1.218
REMOTEIP=192.168.1.219
REMOTEREDISROLE=$REDISCLI -h $REMOTEIP info | grep "<span>role</span>"
if grep "role:master" <<< $REMOTEREDISROLE ; then
start as slave
$REDISPATH/bin/redis-server $REDISPATH/conf/redis_slave.conf<span>if</span> [ "<span>$?</span>" == "<span>0</span>" ];then
echo "<span>[INFO]`date +%F/%H:%M:%S` :$LOCALIP start as slave successful.</span>" >> $LOGFILE<span>else</span>echo "<span>[ERROR]`date +%F/%H:%M:%S` :$LOCALIP start as slave error.</span>" >> $LOGFILE
fi
else#start as master
$REDISPATH/bin/redis-server $REDISPATH/conf/redis_master.confif [ "$?" == "0" ];then
echo "[INFO]date +%F/%H:%M:%S
:$LOCALIP start as master successful." >> $LOGFILEelseecho "[ERROR]date +%F/%H:%M:%S
:$LOCALIP start as master error." >> $LOGFILE
fi
fi
#!/bin/bash
REDISPATH=/usr/local/redis-2.8.3
LOGFILE=$REDISPATH/logs/redis-state.log
kill -9 `ps -ef|grep '/bin/redis-server'|grep -v grep|awk '{print $2}'`
if [ "$?" == "0" ];then
echo "[INFO]`date +%F/%H:%M:%S` :redis shutdown completed!" >> $LOGFILE
elseecho "[ERROR]`date +%F/%H:%M:%S` :redis is not started." >> $LOGFILE
fi
#创建redis配置文件
####192.168.1.218主服务器redis_master.conf对应配置项######
#daemonize no
daemonize yes
#bind 127.0.0.1
bind 192.168.1.218
logfile "/usr/local/redis-2.8.3/logs/redis.log"
#其他配置依据实际生产环境修改
########################################################
####192.168.1.219从服务器redis_master.conf对应配置项######
#daemonize no
daemonize yes
#bind 127.0.0.1
bind 192.168.1.219
logfile "/usr/local/redis-2.8.3/logs/redis.log"
#其他配置依据实际生产环境修改
########################################################
#修改redis_slave.conf对应配置项:
####192.168.1.218主服务器redis_slave.conf对应配置项#######
#daemonize no
daemonize yes
#bind 127.0.0.1
bind 192.168.1.218
logfile "/usr/local/redis-2.8.3/logs/redis.log"
# slaveof
slaveof 192.168.1.219 6379
#其他配置依据实际生产环境修改
########################################################
####192.168.1.219从服务器redis_slave.conf对应配置项#######
#daemonize no
daemonize yes
#bind 127.0.0.1
bind 192.168.1.219
logfile "/usr/local/redis-2.8.3/logs/redis.log"
# slaveof
slaveof 192.168.1.218 6379
#其他配置依据实际生产环境修改
########################################################
#修改redis的属主和权限
chown –R redisadmin:develop /usr/local/redis-2.8.3/
----安装配置keepalived 1.下载keepalived源码Release 1.2.9
注意:最新版为1.2.10测试过程中出错. wget 2.安装keepalived
需要安装以下依赖包: make gcc libpopt-dev libnl-dev libcurl4-openssl-dev popt openssl cd
tar –zxvf keepalived-1.2.9.tar.gz
cd keepalived-1.2.9
./configure --prefix=/usr/local/keepalived
make && make install
3.配置keepalived
#在Master和Slave上创建如下配置文件(可根据实际情况调整):
mv /usr/local/keepalived/etc/keepalived/keepalived.conf /usr/local/keepalived/etc/keepalived/keepalived.conf-bak vim /usr/local/keepalived/etc/keepalived/keepalived.conf
vrrp_script chk_redis {
script "/usr/local/keepalived/etc/keepalived/scripts/chk_redis.sh" ###监控脚本
interval 2 ###监控时间
}
vrrp_instance VI_1 {
state MASTER ###设置为MASTER
interface eth3 ###监控网卡,依据实际情况来定
virtual_router_id 51
priority 101 ###权重值
advert_int 1
authentication {
auth_type PASS ###加密
auth_pass redis ###密码
}
track_script {
chk_redis ###执行上面定义的chk_redis
}
virtual_ipaddress {
192.168.1.220 ###VIP
}
}
在Master和Slave上创建监控Redis的脚本 mkdir /usr/local/keepalived/etc/keepalived/scripts vi /usr/local/keepalived/etc/keepalived/scripts/chk_redis.sh
####以下为master上的配置,slave上的配置只需要修改对应的LOCALIP和REMOTEIP即可。
#!/bin/bash
REDISPATH=/usr/local/redis-2.8.3
REDISCLI=$REDISPATH/bin/redis-cli
LOGFILE=$REDISPATH/logs/redis-state.log
LOCALIP=192.168.1.218
REMOTEIP=192.168.1.219
VIP=192.168.1.220
VIPALIVE=ip a | grep "<span>$VIP</span>"
if [ "$VIPALIVE" == "" ]; then
echo "[info]:"date
" keepalived server is pengding or stop" >> $LOGFILE
else
echo "bbb" >> $LOGFILE
check local service is running
<span>if</span> [ "<span>`$REDISCLI –h $LOCALIP –p 6379 PING`</span>" == "<span>PONG</span>" ]; then
# check local redis server role.
REDISROLE=`$REDISCLI info | grep "<span>role</span>"`
<span>if</span> grep "<span>role:slave</span>" <<< $REDISROLE ; then
#change local redis server as master
echo "<span>[info1]:</span>"`date`"<span> Run SLAVEOF NO ONE cmd ...</span>" >> $LOGFILE
$REDISCLI SLAVEOF NO ONE >> $LOGFILE 2>&1
#change remoting redis server as slave
REMOTEREDISROLE=`$REDISCLI -h $REMOTEIP info | grep "<span>role</span>"`
<span>if</span> grep "<span>role:master</span>" <<< $REMOTEREDISROLE ; then
echo "<span>[info2]:</span>"`date`"<span> Run remote server SLAVEOF cmd ...</span>" >> $LOGFILE
$REDISCLI -h $REMOTEIP SLAVEOF $LOCALIP 6379 >> $LOGFILE 2>&1
fi
<span>else</span>
REMOTEREDISROLE=`$REDISCLI -h $REMOTEIP info | grep "<span>role</span>"`
<span>if</span> grep "<span>role:master</span>" <<< $REMOTEREDISROLE ; then
echo "<span>[info3]:</span>"`date`"<span> Run remote server SLAVEOF cmd ...</span>" >> $LOGFILE
$REDISCLI -h $REMOTEIP SLAVEOF $LOCALIP 6379 >> $LOGFILE 2>&1
fi
fi
<span>else</span>
echo "<span>[warn]:</span>"`date`"<span> redis server($LOCALIP) is not health...</span>" >> $LOGFILE
sleep 1
<span>if</span> [ "<span>`$REDISCLI –h $LOCALIP –p 6379 PING`</span>" != "<span>PONG</span>" ]; then
echo "<span>[error]:</span>"`date`"<span> redis server($LOCALIP) will be stop...</span>" >> $LOGFILE
service keepalived stop
fi
fi
fi
#首先在2台服务器上设置keepalived的启动文件:
cp -a -R -p /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/keepalived
chmod 750 /etc/rc.d/init.d/keepalived
chown root /etc/rc.d/init.d/keepalived #然后在2台服务器上创建配置文件的链接:
mkdir /etc/keepalived/
ln -s /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf
ln -s /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/keepalived
系统测试
注意:一定要先启动redis,再启动keealived,否则redis_check.sh会将keepalived自动关闭。
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 /usr/local/redis-2.8.3/redis-start.sh
#关闭时,直接杀死进程或执行以下脚本
/usr/local/redis-2.8.3/redis-stop.sh
2.启动Slave上的Redis /usr/local/redis-2.8.3/redis-start.sh
#关闭时,直接杀死进程或执行以下脚本
#/usr/local/redis-2.8.3/redis-stop.sh
3.启动Master上的Keepalived /etc/rc.d/init.d/keepalived start
#关闭方法
#/etc/rc.d/init.d/keepalived stop
4.启动Slave上的Keepalived /etc/rc.d/init.d/keepalived start
#关闭方法
#/etc/rc.d/init.d/keepalived stop
继续优化中,未完结。