MySQL 主主复制 + LVS + Keepalived 实现 MySQL 高可用性
Posted 数据分析与开发
tags:
篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了MySQL 主主复制 + LVS + Keepalived 实现 MySQL 高可用性相关的知识,希望对你有一定的参考价值。
bestvivi.com/2015/09/09/mysql主主复制+LVS+Keepalived实现MySQL高可用性/
能够保证数据的冗余的同时可以做读写分离来分担系统压力,如果是主主复制还可以很好的避免主节点的单点故障。但是MySQL主主复制存在一些问题无法满足我们的实际需要:未提供统一访问入口来实现负载均衡,如果其中master宕掉的话需要手动切换到另外一个master,而不能自动进行切换。
这篇文章下面要介绍如何通过LVS+Keepalived的方式来是实现MySQL的高可用性,同时解决以上问题。
Keepalived和LVS介绍
Keepalived是一个基于VRRP(虚拟路由冗余协议)可用来实现服务高可用性的软件方案,避免出现单点故障。Keepalived一般用来实现轻量级高可用性,且不需要共享存储,一般用于两个节点之间,常见有LVS+Keepalived、nginx+Keepalived组合。
LVS(Linux Virtual Server)是一个高可用性虚拟的服务器集群系统。本项目在1998年5月由章文嵩博士成立,是中国国内最早出现的自由软件项目之一。
LVS主要用于多服务器的负载均衡,作用于网络层。LVS构建的服务器集群系统中,前端的负载均衡层被称为Director Server;后端提供服务的服务器组层被称为Real Server。通过下图可以大致了解LVS的基础架构。
本文中将利用LVS实现MySQL的读写负载均衡,Keepalived避免节点出现单点故障。
LVS+Keepalived配置
环境准备
LVS1:192.168.1.2
LVS2:192.168.1.11
MySQL Server1:192.168.1.5
MySQL Server2:192.168.1.6
VIP:192.168.1.100
OS: CentOS 6.4
Keepalive安装
需要安装以下软件包
# yum install -y kernel-devel openssl openssl-devel
解压keepalived到/usr/local/并进入目录执行配置编译
# ./configure --prefix=/usr/local/keepalived --with-kernel-dir=/usr/src/kernels/2.6.32-431.5.1.el6.x86_64/
Keepalived configuration
------------------------
Keepalived version : 1.2.13
Compiler : gcc
Compiler flags : -g -O2
Extra Lib : -lssl -lcrypto -lcrypt
Use IPVS Framework : Yes
IPVS sync daemon support : Yes
IPVS use libnl : No
fwmark socket support : Yes
Use VRRP Framework : Yes
Use VRRP VMAC : Yes
SNMP support : No
SHA1 support : No
Use Debug flags : No
# make
默认情况下keepalived启动时会去/etc/keepalived目录下找配置文件,将需要的配置文件拷贝到指定位置
# cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
# cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
# cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
# cp /usr/local/keepalived/sbin/keepalived /usr/sbin/
# chkconfig mysqld on
# chkconfig keepalived on
LVS安装
需要安装以下软件包
# yum install -y libnl* popt*
查看是否加载lvs模块
# modprobe -l |grep ipvs
解压安装
# ln -s /usr/src/kernels/2.6.32-431.5.1.el6.x86_64/ /usr/src/linux
# tar -zxvf ipvsadm-1.26.tar.gz
# make
LVS安装完成,查看当前LVS集群
# ipvsadm -L -n
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
LVS+Keepalived配置
搭建MySQL主主复制
这里不再赘述,请参考
配置Keepalived
下面是LVS1节点(Keepalived主节点)上的Keepalived配置,LVS2类似
# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id LVS1
}
vrrp_instance VI_1 {
state MASTER #指定instance初始状态,实际根据优先级决定.backup节点不一样
interface eth0 #虚拟IP所在网
priority 100 #优先级,另一台改为90.backup节点不一样
advert_int 1 #检查间隔
authentication {
auth_type PASS #认证方式,可以是pass或ha
auth_pass 1111 #认证密码
}
virtual_ipaddress {
192.168.1.100 #VIP
}
}
virtual_server 192.168.1.100 3306 {
delay_loop 6 #服务轮询的时间间隔
lb_algo wrr #加权轮询调度,LVS调度算法 rr|wrr|lc|wlc|lblc|sh|sh
lb_kind DR #LVS集群模式 NAT|DR|TUN,其中DR模式要求负载均衡器网卡必须有一块与物理网卡在同一个网段
#nat_mask 255.255.255.0
persistence_timeout 50 #会话保持时间
protocol TCP #健康检查协议
## Real Server设置,3306就是MySQL连接端口
real_server 192.168.1.5 3306 {
weight 3 ##权重
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 3306
}
}
real_server 192.168.1.6 3306 {
weight 3
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 3306
}
}
}
配置LVS
编写LVS启动脚本/etc/init.d/realserver
#!/bin/sh
VIP=192.168.1.100
. /etc/rc.d/init.d/functions
case "$1" in
start)
/sbin/ifconfig lo down
/sbin/ifconfig lo up
echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
/sbin/sysctl -p >/dev/null 2>&1
/sbin/route add -host $VIP dev lo:0
echo "LVS-DR real server starts successfully.n"
;;
stop)
/sbin/ifconfig lo:0 down
/sbin/route del $VIP >/dev/null 2>&1
echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
echo "LVS-DR real server stopped.n"
;;
status)
isLoOn=`/sbin/ifconfig lo:0 | grep "$VIP"`
isRoOn=`/bin/netstat -rn | grep "$VIP"`
if [ "$isLoON" == "" -a "$isRoOn" == "" ]; then
echo "LVS-DR real server has run yet."
else
echo "LVS-DR real server is running."
fi
exit 3
;;
*)
echo "Usage: $0 {start|stop|status}"
exit 1
esac
exit 0
将lvs脚本加入开机自启动
# chmod +x /etc/init.d/realserver
# echo "/etc/init.d/realserver" >> /etc/rc.d/rc.local
分别启动LVS和keepalived
# service realserver start
# service keepalived start
注意此时网卡的变化,可以看到虚拟网卡已经分配到了realserver上。
此时查看LVS集群状态,可以看到集群下有两个Real Server,调度算法,权重等信息。ActiveConn代表当前Real Server的活跃连接数
# ipvsadm -ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 192.168.1.100:3306 wrr persistent 50
-> 192.168.1.5:3306 Route 3 4 1
-> 192.168.1.6:3306 Route 3 0 2
此时LVS+Keepalived+MySQL主主复制已经搭建完成。
测试验证
功能性验证
关闭MySQL Server2
# service mysqld stop
在LVS1查看/var/log/messages中关于keepalived日志,LVS1检测到了MySQL Server2宕机,同时LVS集群自动剔除了故障节点
Sep 9 13:50:53 192.168.1.2 Keepalived_healthcheckers[18797]: TCP connection to [192.168.1.6]:3306 failed !!!
Sep 9 13:50:53 192.168.1.2 Keepalived_healthcheckers[18797]: Removing service [192.168.1.6]:3306 from VS [192.168.1.100]:3306
从新启动MySQL Server2后自动将故障节点自动加入LVS集群
Sep 9 13:51:41 192.168.1.2 Keepalived_healthcheckers[18797]: TCP connection to [192.168.1.6]:3306 success.
Sep 9 13:51:41 192.168.1.2 Keepalived_healthcheckers[18797]: Adding service [192.168.1.6]:3306 to VS [192.168.1.100]:3306
关闭LVS1上的Keepalived(模拟宕机操作),查看LVS1上的日志,可以看到Keepalived移出了LVS1上的VIP
Sep 9 14:01:27 192.168.1.2 Keepalived[18796]: Stopping Keepalived v1.2.13 (09/09,2014)
Sep 9 14:01:27 192.168.1.2 Keepalived_healthcheckers[18797]: Removing service [192.168.1.5]:3306 from VS [192.168.1.100]:3306
Sep 9 14:01:27 192.168.1.2 Keepalived_healthcheckers[18797]: Removing service [192.168.1.6]:3306 from VS [192.168.1.100]:3306
Sep 9 14:01:27 192.168.1.2 Keepalived_vrrp[18799]: VRRP_Instance(VI_1) sending 0 priority
Sep 9 14:01:27 192.168.1.2 Keepalived_vrrp[18799]: VRRP_Instance(VI_1) removing protocol VIPs.
同时查看LVS2上日志,可以看到LVS2成为了Master,并接管了VIP
Sep 9 14:11:24 192.168.1.11 Keepalived_vrrp[7457]: VRRP_Instance(VI_1) Transition to MASTER STATE
Sep 9 14:11:25 192.168.1.11 Keepalived_vrrp[7457]: VRRP_Instance(VI_1) Entering MASTER STATE
Sep 9 14:11:25 192.168.1.11 Keepalived_vrrp[7457]: VRRP_Instance(VI_1) setting protocol VIPs.
Sep 9 14:11:25 192.168.1.11 Keepalived_vrrp[7457]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 192.168.1.100
Sep 9 14:11:25 192.168.1.11 Keepalived_healthcheckers[7456]: Netlink reflector reports IP 192.168.1.100 added
Sep 9 14:11:25 192.168.1.11 avahi-daemon[1407]: Registering new address record for 192.168.1.100 on eth0.IPv4.
Sep 9 14:11:30 192.168.1.11 Keepalived_vrrp[7457]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 192.168.1.100
在LVS2上查看LVS集群状态,一切正常。
# ipvsadm -ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 192.168.1.100:3306 wrr persistent 50
-> 192.168.1.5:3306 Route 3 2 0
-> 192.168.1.6:3306 Route 3 1 0
总结
MySQL主主复制是集群的基础,组成Server Array,其中每个节点作为Real Server。
LVS服务器提供了负载均衡的作用,将用户请求分发到Real Server,一台Real Server故障并不会影响整个集群。
Keepalived搭建主备LVS服务器,避免了LVS服务器的单点故障,出现故障时可以自动切换到正常的节点。
觉得本文有帮助?请分享给更多人
关注「数据库开发」,提升数据库开发技术
以上是关于MySQL 主主复制 + LVS + Keepalived 实现 MySQL 高可用性的主要内容,如果未能解决你的问题,请参考以下文章
MySQL 主主复制 + LVS + Keepalived 实现 MySQL 高可用性
MySQL 主主复制 + LVS + Keepalived 实现 MySQL 高可用性
MySQL主主复制+LVS+Keepalived实现MySQL高可用性