mysql架构为主从形式，当master故障时，会自动切换到slave上，当然也可设置为双master，但是有个弊端，比如，当某用户发表文章时，由于此时主机的压力很大，假设落后2000s，那么这台主机就挂了，另一台主机接管，vip漂移到从机上时，因为同步延长大，用户刚才发表的文章还没有复制过来，于是用户又发表了一篇文章，当原来的master修好后，由于SQL和IO线程还处于开启状态，因此还会继续同步刚才没有复制完的数据，这时有可能把用户新发表的文章更改掉，造成用户数据丢失。主从架构，故障切换后，采取人工方式重新与新的master进行同步复制。
1.1. 安装
[[email protected] home]# tar -zxvfkeepalived-1.2.7.tar.gz
[[email protected] home]# cd keepalived-1.2.7
[[email protected] keepalived-1.2.7]#./configure --prefix=/usr/local/keepalived
........
Keepalived configuration
------------------------
Keepalived version : 1.2.7
Compiler : gcc
Compiler flags : -g -O2 -DETHERTYPE_IPV6=0x86dd
Extra Lib : -lpopt -lssl -lcrypto
Use IPVS Framework : Yes
IPVS sync daemon support : Yes
IPVS use libnl : No
Use VRRP Framework : Yes
Use VRRP VMAC : No
SNMP support : No
Use Debug flags : No
[[email protected] keepalived-1.2.7]#
[[email protected] keepalived-1.2.7]# mkdir/etc/keepalived
[[email protected] keepalived-1.2.7]# cp/usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
[[email protected] keepalived-1.2.7]# cp/usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
[[email protected] keepalived-1.2.7]# cp/usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
[[email protected] keepalived-1.2.7]# cp/usr/local/keepalived/sbin/keepalived /usr/sbin/
[[email protected] keepalived-1.2.7]# chkconfig--add keepalived
[[email protected] keepalived-1.2.7]# chkconfig--level 345 keepalived on
[[email protected] keepalived-1.2.7]#
1.1.1. keepalived安装成功检查
[[email protected] keepalived]# ll
total 16
drwxr-xr-x 2 root root 4096 Jul 24 13:26bin
drwxr-xr-x 5 root root 4096 Jul 24 13:26etc
drwxr-xr-x 2 root root 4096 Jul 24 13:26sbin
drwxr-xr-x 3 root root 4096 Jul 24 13:26share
[[email protected] keepalived]# cd etc/
[[email protected] etc]# ll
total 12
drwxr-xr-x 3 root root 4096 Jul 24 13:26keepalived
drwxr-xr-x 3 root root 4096 Jul 24 13:26rc.d
drwxr-xr-x 2 root root 4096 Jul 24 13:26sysconfig
[[email protected] etc]# cd keepalived/
1.2. 主服务器配置1.2.1. keepalived配置
[[email protected] keepalived-1.2.7]# cd/etc/keepalived/
[[email protected] keepalived]# vikeepalived.conf
| global_defs { router_id KeepAlive_Mysql } vrrp_script check_run { script "/home/sh/mysql_check.sh" interval 300 } vrrp_sync_group VG1 { group { VI_1 } } vrrp_instance VI_1 { state MASTER #备服务器改为BACKUP # state BACKUP interface eth0 virtual_router_id 51 priority 100 #备服务器改为90 # priority 90 advert_int 1 nopreempt authentication { auth_type PASS auth_pass 1111 } track_script { check_run } notify_master /home/sh/master.sh notify_backup /home/sh/backup.sh notify_stop /home/sh/stop.sh virtual_ipaddress { 192.168.6.200 } } |
notify_master：状态改变为master后执行的脚本；
notify_backup：状态改变为backup后执行的脚本；
notify_stop：VRRP停止后执行的脚本
使用到四个脚本：mysql_check.sh、master.sh、backup.sh、stop.sh
1.2.2. 健康检查脚本
[[email protected]]# vi mysql_check.sh
| #!/bin/bash . /root/.bash_profile count=1 while true do mysql -e "show status;" > /dev/null 2>&1 i=$? ps aux | grep mysqld | grep -v grep > /dev/null 2>&1 j=$? if [ $i = 0 ] && [ $j = 0 ] then exit 0 else if [ $i = 1 ] && [ $j = 0 ] then exit 0 else if [ $count -gt 5 ] then break fi let count++ continue fi fi done /etc/init.d/keepalived stop |
首先判断同步复制是否执行完毕，如果没执行完毕，等1分钟，不论是否执行，都跳过，并停止同步复制进程，其次，更改前端程序连接的业务账号admin的权限和密码，并记录当前切换以后的日志和pos点。
1.2.3. 主服务器脚本
[[email protected]]# vi master.sh
| #!/bin/bash . /root/.bash_profile Master_Log_File=$(mysql -e "show slave statusG" | grep -w Master_Log_File | awk -F": " ‘{print $2}‘) Relay_Master_Log_File=$(mysql -e "show slave statusG" | grep -w Relay_Master_Log_File | awk -F": " ‘{print $2}‘) Read_Master_Log_Pos=$(mysql -e "show slave statusG" | grep -w Read_Master_Log_Pos | awk -F": " ‘{print $2}‘) Exec_Master_Log_Pos=$(mysql -e "show slave statusG" | grep -w Exec_Master_Log_Pos | awk -F": " ‘{print $2}‘) i=1 while true do if [ $Master_Log_File = $Relay_Master_Log_File ] && [ $Read_Master_Log_Pos -eq $Exec_Master_Log_Pos ] then echo "ok" break else sleep 1 if [ $i -gt 60 ] then break fi continue let i++ fi done mysql -e "stop slave;" mysql -e "set global innodb_support_xa=0;" mysql -e "set global sync_binlog=0;" mysql -e "set global innodb_flush_log_at_trx_commit=0;" mysql -e "flush logs;GRANT ALL PRIVILEGES ON *.* TO ‘admin‘@‘%‘ IDENTIFIED BY ‘123456‘;flush privileges;" mysql -e "show master status;" > /tmp/master_status_$(date "+%y%m%d-%H%M").txt |
1.2.4. 备服务器脚本
[[email protected]]# vi backup.sh
| #!/bin/bash . /root/.bash_profile mysql -e "GRANT ALL PRIVILEGES ON *.* TO ‘admin‘@‘%‘ IDENTIFIED BY ‘1q2w3e4r‘;flush privileges;" mysql -e "set global event_scheduler=0;" mysql -e "set global innodb_support_xa=0;" mysql -e "set global sync_binlog=0;" mysql -e "set global innodb_flush_log_at_trx_commit=0;" |
1.2.5. keepalived停止后执行的脚本
stop.sh表示keepalived停止后执行的脚本，首先更改admin密码，其次设置参数，保证不丢失数据，最后查看是否有写操作，不论是否执行完毕，1分钟后退出：
[[email protected] keepalived]# vi stop.sh
| #!/bin/bash . /root/.bash_profile mysql -e "GRANT ALL PRIVILEGES ON *.* TO ‘admin‘@‘%‘ IDENTIFIED BY ‘1q2w3e4r‘;flush privileges;" mysql -e "set global innodb_support_xa=1;" mysql -e "set global sync_binlog=1;" mysql -e "set global innodb_flush_log_at_trx_commit=1;" M_File1=$(mysql -e "show master statusG" | awk -F‘: ‘ ‘/File/{print $2}‘) M_Position1=$(mysql -e "show master statusG" | awk -F‘: ‘ ‘/Position/{print $2}‘) sleep 1 M_File2=$(mysql -e "show master statusG" | awk -F‘: ‘ ‘/File/{print $2}‘) M_Position2=$(mysql -e "show master statusG" | awk -F‘: ‘ ‘/Position/{print $2}‘) i=1 while true do if [ $M_File1 = $M_File1 ] && [ $M_Position1 -eq $M_Position2 ] then echo "ok" break else sleep 1 if [ $i -gt 60 ] then break fi continue let i++ fi done |
至此，配置完毕，只要把master关机或者把mysq停掉，vip就会漂移到slave上，在把原来的master修复好后，vip并不会自己漂移过去，仍旧会停留在slave上，这样做的好处是防止数据频繁切换导致数据不一致。
1.3. keepalived管理
查看进程：
[[email protected] keepalived]# ps -aux|grepkeepalived
Warning: bad syntax, perhaps a bogus ‘-‘?See /usr/share/doc/procps-3.2.7/FAQ
root 4147 0.0 0.0 4016 676 pts/1 R+ 13:42 0:00 grep keepalived
[[email protected] keepalived]# servicekeepalived start
Starting keepalived: [ OK ]
[[email protected] keepalived]# ps -aux|grepkeepalived
Warning: bad syntax, perhaps a bogus ‘-‘?See /usr/share/doc/procps-3.2.7/FAQ
root 4158 0.0 0.0 5040 576 ? Ss 13:42 0:00 keepalived -D
root 4159 0.0 0.1 5088 1428 ? S 13:42 0:00 keepalived -D
root 4160 0.1 0.0 5088 936 ? S 13:42 0:00 keepalived -D
root 4163 0.0 0.0 4016 672 pts/1 R+ 13:43 0:00 grep keepalived
[[email protected] keepalived]# lsmod|grep ip_vs
ip_vs_rr 6081 3
ip_vs 78081 5 ip_vs_rr
[[email protected] keepalived]# tail -f/var/log/messages
Jul 24 13:44:44 gflinuxKeepalived_healthcheckers[4159]: Timeout connect, timeout server[192.168.200.5]:1358.
Jul 24 13:44:50 gflinuxKeepalived_healthcheckers[4159]: Timeout connect, timeout server [192.168.201.100]:443.
Jul 24 13:44:50 gflinuxKeepalived_healthcheckers[4159]: Timeout connect, timeout server[192.168.200.2]:1358.
Jul 24 13:44:56 gflinuxKeepalived_healthcheckers[4159]: Timeout connect, timeout server[192.168.201.100]:443.
Jul 24 13:44:56 gflinuxKeepalived_healthcheckers[4159]: Timeout connect, timeout server[192.168.200.2]:1358.
Jul 24 13:44:56 gflinuxKeepalived_healthcheckers[4159]: Timeout connect, timeout server[192.168.200.3]:1358.
Jul 24 13:44:56 gflinuxKeepalived_healthcheckers[4159]: Timeout connect, timeout server[192.168.200.4]:1358.
Jul 24 13:44:56 gflinuxKeepalived_healthcheckers[4159]: Timeout connect, timeout server[192.168.200.5]:1358.
Jul 24 13:45:02 gflinuxKeepalived_healthcheckers[4159]: Timeout connect, timeout server[192.168.201.100]:443.
Jul 24 13:45:02 gflinuxKeepalived_healthcheckers[4159]: Timeout connect, timeout server[192.168.200.2]:1358.
Jul 24 13:45:08 gflinuxKeepalived_healthcheckers[4159]: Timeout connect, timeout server[192.168.201.100]:443.
Jul 24 13:45:08 gflinuxKeepalived_healthcheckers[4159]: Timeout connect, timeout server[192.168.200.2]:1358.
Jul 24 13:45:08