利用LVS+Keepalived实现MySQL高可用1
MySQL架构
MySQL 服务器组成,平时只有主库提供服务,备库不提供服务。当主库停止服务时,服务自动切换到备库。主备库通过双向复制,保证数据一致性。主备库以 MySQL 对外服务接口的 Keepalived 来实现心跳检查和动态漂移。因此 Keepalived 部署在同一台服务器上,每台 realserver 即自身机器的 LVS 源码安装- ln -s /usr/src/kernels/2.6.32-279.14.1.el6.x86_64/ /usr/src/linux
- tar zxvf ipvsadm-1.24.tar.gz
- cd ipvsadm-1.24
- make && make install
Keepalived源码安装
安装依赖包
yum -y install popt-devel
安装 IP 配置如下库 |
IP |
服务VIP |
主 |
10.0.0.77 |
10.0.0.76 |
备 |
10.0.0.78 |
Keepalived 配置文件 /etc/keepalived/keepalived.conf ,主库为例
点击(此处)折叠或打开
- global_defs {
- router_id LVS_1
- }
- vrrp_sync_group test {
- group {
- mysql_ha
- }
- }
- vrrp_instance mysql_ha {
- state BACKUP ##主备库都是BACKUP,防止主库重启后,抢夺VIP资源
- interface eth0 ## HA地址网卡
- virtual_router_id 61
- priority 150 ##优先级,主库比备库高
- nopreempt ##非抢夺,在主库上配置,表示不抢夺VIP
- advert_int 1 ## 主备心跳检查间隔
- authentication {
- auth_type PASS
- auth_pass 1111
- }
- virtual_ipaddress { ## VIP,主备库一样
- 10.0.0.76
- }
- ## 以下脚本是Keepalived改变状态时触发的动作,分别是变为backup、master、fault状态
- ## 这是个简单的报警脚本而已
- notify_backup "/usr/local/keepalived_script/keepalived_notify.sh BACKUP"
- notify_master "/usr/local/keepalived_script/keepalived_notify.sh MASTER"
- notify_fault "/usr/local/keepalived_script/keepalived_notify.sh FAULT"
- notify "/usr/local/keepalived_script/keepalived_notify.sh "
- }
- virtual_server 10.0.0.76 3306 {
- delay_loop 2
- lb_algo rr
- lb_kind DR
- persistence_timeout 20
- protocol TCP
- real_server 10.0.0.77 3306 { ##keepalived的realserver,主备库都取自身的mysql服务
- weight 3
- notify_down "/usr/local/keepalived_script/keepalived_notify.sh MYSQL_DOWN" ## 检测到realserver服务不可用时的动作
- TCP_CHECK {
- connect_timeout 3
- nb_get_retry 3
- delay_before_retry 3
- connect_port 3306
- }
- }
- }
测试
测试效果
从以下4个方面测试HA效果
keepalived down
mysqld down
网络故障
机器宕机
测试步骤和结果
keepalived down
步骤:kill master上的keepalived进程
结果:
>>slave的keepalived通知切换为master
mysqld down
步骤:kill master上的mysqld进程,或者提高master服务器的负载
结果:
>>master的keepalived通知因为mysqld down而停止keepalived
>>slave的keepalived通知切换为master
网络故障
步骤:master上ifconfig eth0 down,或者service network restart
结果:
>>master的keepalived通知变为fault状态
>>slave的keepalived通知切换为master
机器宕机
步骤:master机器重启
结果:
>>slave的keepalived通知切换为master
问题分析
1,keepalived切换为master时,arping失败
有的环境测试,keepalived切换为master时,没有成功发送arping,导致VIP不同。所以给出了arping脚本
2,重启网卡,master变为fault状态,但没继续变为backup状态。
检查日志发现有错误信息
Keepalived_vrrp: Netlink: filter function error
Keepalived_healthcheckers: Netlink: filter function error
查找网络资料得知,keepalive不支持网络设备热插拔。ip link可以看出设备id变化了。
此时需要reload keepalived或者直接restart。
办法:网卡发生重启后,需检查keepalived是否正常
3,keepalived异常终止,VIP没有解除绑定,导致及时重启keepalived后,这个VIP也不能正常绑定和解除绑定
猜测原因是异常终止keepalived后,VIP没解除绑定,重启以后keepalived不识别未解除绑定的VIP。
办法:机器发生重启后需检查keepalived是否正常
4,ipvsadm使用yum安装,keepalived使用源码安装,keepalived不能启动healthchecker进程
keepalived安装时指定kernel目录:./configure --prefix=/usr/local/keepalived --with-kernel-dir=/usr/src/kernels/2.6.18-308.1.1.el5-x86_64
5,关于virtual_router_id
virtual_router_id用来标识一对keepalived主从机的身份,不同keepalived对的这个id不能一样。取值范围1~255。如果不同组keepalived配置了同一个id,则会有如下报错:
Apr7 14:31:11 localhost Keepalived_vrrp[22980]:ip address associated with VRID not present in received packet : 10.0.0.94 Apr7 14:31:11 localhostKeepalived_vrrp[22980]:one or more VIP associated with VRID mismatch actual MASTER advert Apr7 14:31:11 localhost Keepalived_vrrp[22980]: bogus VRRP packet received on eth0.181 !!! Apr7 14:31:11 localhost Keepalived_vrrp[22980]: VRRP_Instance(mysql_ha) ignoring received advertisment... |
6,端口转发
real_server配置的端口必须一样?
转载 :http://blog.chinaunix.net/uid-23500957-id-3781918.html
更多相关文章
- PLSQL并非所有变量都已绑定
- 绑定本地Service和远程Service并调用其中方法
- Android中bindService的细节之二:从进程的角度分析绑定Service的
- Android 通知(Notification)的基本用法
- jsp权限菜单绑定的基本实现
- android自定义通知,android自定义Notification
- Android绑定银行卡提现怎么做?
- 绑定服务后台播放音频的简单示例
- android发送通知及更新通知