MHA 自动故障转移步骤及过程剖析

曾经终败给现在 2022-08-07 16:57 174阅读 0赞

MHA是众多使用MySQL数据库企业高可用的不二选择，它简单易用，功能强大，实现了基于MySQL replication架构的自动主从故障转移，本文主要描述了MHA自动切换的步骤，对切换过程做了演示以及进行了适当的分析，供大家参考和理解MHA以及MySQL的原理。

1、MHA自动切换的步骤  
a、MHA manager启动时的校验阶段  
   根据配置文件校验复制配置以及识别当前的master  
   导致监控终止情形：复制配置异常，存在的异常slave，一些需要的脚本脚本异常  
   MHA manager启动前可以通过masterha\_check\_ssh以及masterha\_check\_repl检测

b、监控master server阶段  
   MHA manager启动成功后，输出日志\[info\] Ping(SELECT) succeeded, waiting until MySQL doesn't respond..  
   MHA会定期ping master，缺省的间隔为1秒，直到master死掉  
   MHA manager不会监控slave的状态，任意的Stopping/Restarting/Adding/Removing slaves不影响当前MHA监控  
   当添加或移除slave节点时，建议修改配置文件以及重启MHA manager

c、侦测到master server异常阶段  
   3次连续ping master失败，参数secondary\_check\_script可用于double check

d、开启failover阶段  
   MHA再次读取配置文件(防止主从配置已更改)，校验master以及当前masetr的从库  
   MHA也会校验诸如复制异常以及是否存在一些从库有不同的主  
   启动failover（排除上次failover失败或者failover时间间隔太短）

e、隔离master server阶段（可选）

如果配置文件定义了IP漂移脚本则此时会关闭master IP  
   如果配置文件定义了关闭master脚本，则调用脚本关闭master以避免脑裂

f、恢复一个新的master  
   从slave节点获取最新的end\_log\_pos (Read\_Master\_Log\_Pos)位置  
   从上一步获取的位置开始，读取及保存crashed master全部二进制日志文件（ssh可达）  
   决定新的master（根据配置文件定义的优先级别）  
   产生差量的binary/relay log events并且apply到新的master

g、激活一个新的master  
   如果配置文件定义了IP漂移脚本则此时会将IP漂移到新master

i、恢复剩余的slave  
   对所有从库并行地产生差量binary/relay log events  
   并用apply差量binary/relay log events到各从库  
   启动复制  
   
j、通知切换结果（可选）  
   邮件发送  
   备份作业，管理工具调整等

2、MHA配置信息   
\[root@vdbsrv4 ~\]$ more /etc/masterha/app1.cnf  
\[server default\]  
manager\_workdir=/var/log/masterha/app1  
manager\_log=/var/log/masterha/app1/manager.log

user=mha  
password=xxx  
ssh\_user=root  
repl\_user=repl    
repl\_password=repl    
ping\_interval=1  
shutdown\_script=""  
master\_ip\_online\_change\_script=""  
report\_script=""  
master\_ip\_failover\_script=/tmp/master\_ip\_failover  
   
\[server1\]  
hostname=vdbsrv1  
master\_binlog\_dir=/data/mysqldata

\[server2\]  
hostname=vdbsrv2  
master\_binlog\_dir=/data/mysqldata

\[server3\]  
hostname=vdbsrv3  
master\_binlog\_dir=/data/mysqldata/  
\#candidate\_master=1

\[root@vdbsrv1 ~\]\# more /etc/hosts  
127.0.0.1    localhost.localdomain localhost  
192.168.1.6  vdbsrv1  \#master  
192.168.1.7  vdbsrv2  \#slave1  
192.168.1.8  vdbsrv3  \#slave2  
192.168.1.12 vdbsrv4  \#manager

3、演示切换  
\#\#\#开启主库VIP  
\[root@vdbsrv4 ~\]\# ssh vdbsrv1 "/sbin/ifconfig eth0:0 192.168.1.13 netmask 255.255.255.0 up"

\#\#\#开启MHA manager  
\[root@vdbsrv4 ~\]\# nohup masterha\_manager --conf=/etc/masterha/app1.cnf &

\#\#\#使用sysbench产生事务  
\[root@vdbsrv1 ~\]\# sysbench --test=oltp           \\  
> --oltp-table-size=5000000      \\  
> --oltp-read-only=off           \\  
> --init-rng=on                  \\  
> --num-threads=16               \\  
> --max-requests=0               \\  
> --oltp-dist-type=uniform       \\  
> --max-time=180                 \\  
> --mysql-user=root              \\  
> --mysql-socket=/tmp/mysql.sock \\  
> --mysql-password=''            \\  
> --db-driver=mysql              \\  
> --mysql-table-engine=innodb    \\  
> --oltp-test-mode=complex       \\  
> --mysql-db=replicatedb run  
sysbench 0.4.12:  multi-threaded system evaluation benchmark

\#\#\#从库vdbsrv2停止io进程以模拟io滞后  
\[root@vdbsrv2 ~\]\# mysql -e 'stop slave io\_thread'  
\[root@vdbsrv2 ~\]\# mysql -e 'show slave status\\G' | egrep 'Slave\_IO|Slave\_SQL'  
               Slave\_IO\_State:  
             Slave\_IO\_Running: No           \#\#\#Author : Leshami  
            Slave\_SQL\_Running: Yes          \#\#\#Blog   : [http://blog.csdn.net/leshami][http_blog.csdn.net_leshami]  
      Slave\_SQL\_Running\_State: Slave has read all relay log; waiting for the slave I/O thread to update it

\#\#\#2分钟后从库vdbsrv2启动io进程       
\[root@vdbsrv2 ~\]\# mysql -e 'start slave io\_thread'

\#\#\#从库vdbsrv3停止io进程以模拟io滞后  
\[root@vdbsrv3 ~\]\# mysql -e 'stop slave io\_thread'

\#\#\#模拟主库宕机  
\[root@vdbsrv4 ~\]\# ssh vdbsrv1 "killall -r mysqld"

\#\#\#主库的sysbench被强制断开且伴随下列错误提示  
\[root@vdbsrv1 ~\]\#  
     .......  
Doing OLTP test.  
Running mixed OLTP test  
Using Uniform distribution  
Using "BEGIN" for starting transactions  
Using auto\_inc on the id column  
Threads started!  
ALERT: failed to execute mysql\_stmt\_execute(): Err1317 Query execution was interrupted  
FATAL: database error, exiting...  
ALERT: failed to execute mysql\_stmt\_execute(): Err1317 Query execution was interrupted  
FATAL: database error, exiting...

\#\#\#查看VIP漂移情况  
\[root@vdbsrv4 app1\]\# grep VIP /var/log/masterha/app1/manager.log  
Disabling the VIP on old master: vdbsrv1  
Enabling the VIP - 192.168.1.13/24 on the new master - vdbsrv2

4、MHA日志初步剖析

\[root@vdbsrv4 ~\]\# ls -hltr /var/log/masterha/\*  
total 32K  
\-rw-r--r-- 1 root root 143 Apr 20 14:30 saved\_master\_binlog\_from\_vdbsrv1\_3306\_20150420143022.binlog  
\-rw-r--r-- 1 root root 26K Apr 20 14:30 manager.log  
\-rw-r--r-- 1 root root   0 Apr 20 14:30 app1.failover.complete

\#\#\#具体日志信息manager.log

Mon Apr 20 14:27:41 2015 - \[info\] MHA::MasterMonitor version 0.56.  
Mon Apr 20 14:27:42 2015 - \[info\] GTID failover mode = 0  
Mon Apr 20 14:27:42 2015 - \[info\] Dead Servers:  
Mon Apr 20 14:27:42 2015 - \[info\] Alive Servers:  
Mon Apr 20 14:27:42 2015 - \[info\]   vdbsrv1(192.168.1.6:3306)  
Mon Apr 20 14:27:42 2015 - \[info\]   vdbsrv2(192.168.1.7:3306)  
Mon Apr 20 14:27:42 2015 - \[info\]   vdbsrv3(192.168.1.8:3306)  
Mon Apr 20 14:27:42 2015 - \[info\] Alive Slaves:  
Mon Apr 20 14:27:42 2015 - \[info\]   vdbsrv2(192.168.1.7:3306)  Version=5.6.22-log (oldest major version between slaves) log-bin:enabled  
Mon Apr 20 14:27:42 2015 - \[info\]     Replicating from 192.168.1.6(192.168.1.6:3306)  
Mon Apr 20 14:27:42 2015 - \[info\]   vdbsrv3(192.168.1.8:3306)  Version=5.6.22-log (oldest major version between slaves) log-bin:enabled  
Mon Apr 20 14:27:42 2015 - \[info\]     Replicating from 192.168.1.6(192.168.1.6:3306)  
Mon Apr 20 14:27:42 2015 - \[info\] Current Alive Master: vdbsrv1(192.168.1.6:3306)  
Mon Apr 20 14:27:42 2015 - \[info\] Checking slave configurations..  
Mon Apr 20 14:27:42 2015 - \[info\]  read\_only=1 is not set on slave vdbsrv2(192.168.1.7:3306).  
Mon Apr 20 14:27:42 2015 - \[info\] Checking replication filtering settings..  
Mon Apr 20 14:27:42 2015 - \[info\]  binlog\_do\_db= , binlog\_ignore\_db=  
Mon Apr 20 14:27:42 2015 - \[info\]  Replication filtering check ok.  
Mon Apr 20 14:27:42 2015 - \[info\] GTID (with auto-pos) is not supported  
Mon Apr 20 14:27:42 2015 - \[info\] Starting SSH connection tests..  
Mon Apr 20 14:27:43 2015 - \[info\] All SSH connection tests passed successfully.  
Mon Apr 20 14:27:43 2015 - \[info\] Checking MHA Node version..  
Mon Apr 20 14:27:44 2015 - \[info\]  Version check ok.  
Mon Apr 20 14:27:44 2015 - \[info\] Checking SSH publickey authentication settings on the current master..  
Mon Apr 20 14:27:44 2015 - \[info\] HealthCheck: SSH to vdbsrv1 is reachable.  
Mon Apr 20 14:27:44 2015 - \[info\] Master MHA Node version is 0.56.  
Mon Apr 20 14:27:44 2015 - \[info\] Checking recovery script configurations on vdbsrv1(192.168.1.6:3306)..  
Mon Apr 20 14:27:44 2015 - \[info\]   Executing command: save\_binary\_logs --command=test --start\_pos=4 --binlog\_dir=/data/mysqldata  
     --output\_file=/var/tmp/save\_binary\_logs\_test --manager\_version=0.56 --start\_file=mysql-bin.000020  
Mon Apr 20 14:27:44 2015 - \[info\]   Connecting to root@192.168.1.6(vdbsrv1:22)..  
  Creating /var/tmp if not exists..    ok.  
  Checking output directory is accessible or not..  
   ok.  
  Binlog found at /data/mysqldata, up to mysql-bin.000020  
Mon Apr 20 14:27:44 2015 - \[info\] Binlog setting check done.  
Mon Apr 20 14:27:44 2015 - \[info\] Checking SSH publickey authentication and checking recovery script configurations on all alive slave servers..  
Mon Apr 20 14:27:44 2015 - \[info\]   Executing command : apply\_diff\_relay\_logs --command=test --slave\_user='mha' --slave\_host=vdbsrv2  
 --slave\_ip=192.168.1.7 --slave\_port=3306 --workdir=/var/tmp --target\_version=5.6.22-log --manager\_version=0.56  
 --relay\_log\_info=/data/mysqldata/relay-log.info  --relay\_dir=/data/mysqldata/  --slave\_pass=xxx  
Mon Apr 20 14:27:44 2015 - \[info\]   Connecting to root@192.168.1.7(vdbsrv2:22)..  
  Checking slave recovery environment settings..  
    Opening /data/mysqldata/relay-log.info ... ok.  
    Relay log found at /data/mysqldata, up to vdbsrv2-relay-bin.000002  
    Temporary relay log file is /data/mysqldata/vdbsrv2-relay-bin.000002  
    Testing mysql connection and privileges.. done.  
    Testing mysqlbinlog output.. done.  
    Cleaning up test file(s).. done.  
Mon Apr 20 14:27:45 2015 - \[info\]   Executing command : apply\_diff\_relay\_logs --command=test --slave\_user='mha'  
  --slave\_host=vdbsrv3 --slave\_ip=192.168.1.8 --slave\_port=3306 --workdir=/var/tmp --target\_version=5.6.22-log  
  --manager\_version=0.56 --relay\_log\_info=/data/mysqldata/relay-log.info  --relay\_dir=/data/mysqldata/  --slave\_pass=xxx  
Mon Apr 20 14:27:45 2015 - \[info\]   Connecting to root@192.168.1.8(vdbsrv3:22)..  
  Checking slave recovery environment settings..  
    Opening /data/mysqldata/relay-log.info ... ok.  
    Relay log found at /data/mysqldata, up to vdbsrv3-relay-bin.000002  
    Temporary relay log file is /data/mysqldata/vdbsrv3-relay-bin.000002  
    Testing mysql connection and privileges.. done.  
    Testing mysqlbinlog output.. done.  
    Cleaning up test file(s).. done.  
Mon Apr 20 14:27:45 2015 - \[info\] Slaves settings check done.  
Mon Apr 20 14:27:45 2015 - \[info\]  
vdbsrv1(192.168.1.6:3306) (current master)  
 +--vdbsrv2(192.168.1.7:3306)  
 +--vdbsrv3(192.168.1.8:3306)

Mon Apr 20 14:27:45 2015 - \[info\] Checking master\_ip\_failover\_script status:  
Mon Apr 20 14:27:45 2015 - \[info\]   /tmp/master\_ip\_failover --command=status --ssh\_user=root --orig\_master\_host=vdbsrv1  
  --orig\_master\_ip=192.168.1.6 --orig\_master\_port=3306

IN SCRIPT TEST====/sbin/ifconfig eth0:0 down==/sbin/ifconfig eth0:0 192.168.1.13/24===

Checking the Status of the script.. OK  
Mon Apr 20 14:27:45 2015 - \[info\]  OK.  
Mon Apr 20 14:27:45 2015 - \[warning\] shutdown\_script is not defined.  
Mon Apr 20 14:27:45 2015 - \[info\] Set master ping interval 1 seconds.  
Mon Apr 20 14:27:45 2015 - \[warning\] secondary\_check\_script is not defined. It is highly recommended setting it to check master  
           reachability from two or more routes.  
Mon Apr 20 14:27:45 2015 - \[info\] Starting ping health check on vdbsrv1(192.168.1.6:3306)..  
Mon Apr 20 14:27:45 2015 - \[info\] Ping(SELECT) succeeded, waiting until MySQL doesn't respond..  
Mon Apr 20 14:30:19 2015 - \[warning\] Got error on MySQL select ping: 2013 (Lost connection to MySQL server during query) \#\#\#侦测到错误  
Mon Apr 20 14:30:19 2015 - \[info\] Executing SSH check script: save\_binary\_logs --command=test --start\_pos=4 --binlog\_dir=/data/mysqldata  
 --output\_file=/var/tmp/save\_binary\_logs\_test --manager\_version=0.56 --binlog\_prefix=mysql-bin  
Mon Apr 20 14:30:19 2015 - \[info\] HealthCheck: SSH to vdbsrv1 is reachable.  
Mon Apr 20 14:30:20 2015 - \[warning\] Got error on MySQL connect: 2003 (Can't connect to MySQL server on '192.168.1.6' (111))  
Mon Apr 20 14:30:20 2015 - \[warning\] Connection failed 2 time(s)..  
Mon Apr 20 14:30:21 2015 - \[warning\] Got error on MySQL connect: 2003 (Can't connect to MySQL server on '192.168.1.6' (111))  
Mon Apr 20 14:30:21 2015 - \[warning\] Connection failed 3 time(s)..  
Mon Apr 20 14:30:22 2015 - \[warning\] Got error on MySQL connect: 2003 (Can't connect to MySQL server on '192.168.1.6' (111))  
Mon Apr 20 14:30:22 2015 - \[warning\] Connection failed 4 time(s)..  
Mon Apr 20 14:30:22 2015 - \[warning\] Master is not reachable from health checker!  
Mon Apr 20 14:30:22 2015 - \[warning\] Master vdbsrv1(192.168.1.6:3306) is not reachable!  
Mon Apr 20 14:30:22 2015 - \[warning\] SSH is reachable.  
Mon Apr 20 14:30:22 2015 - \[info\] Connecting to a master server failed. Reading configuration file /etc/masterha\_default.cnf and  
  /etc/masterha/app1.cnf again, and trying to connect to all servers to check server status..  
Mon Apr 20 14:30:22 2015 - \[warning\] Global configuration file /etc/masterha\_default.cnf not found. Skipping.  
Mon Apr 20 14:30:22 2015 - \[info\] Reading application default configuration from /etc/masterha/app1.cnf..  
Mon Apr 20 14:30:22 2015 - \[info\] Reading server configuration from /etc/masterha/app1.cnf..  
Mon Apr 20 14:30:22 2015 - \[info\] GTID failover mode = 0  
Mon Apr 20 14:30:22 2015 - \[info\] Dead Servers:  
Mon Apr 20 14:30:22 2015 - \[info\]   vdbsrv1(192.168.1.6:3306)  
Mon Apr 20 14:30:22 2015 - \[info\] Alive Servers:  
Mon Apr 20 14:30:22 2015 - \[info\]   vdbsrv2(192.168.1.7:3306)  
Mon Apr 20 14:30:22 2015 - \[info\]   vdbsrv3(192.168.1.8:3306)  
Mon Apr 20 14:30:22 2015 - \[info\] Alive Slaves:  
Mon Apr 20 14:30:22 2015 - \[info\]   vdbsrv2(192.168.1.7:3306)  Version=5.6.22-log (oldest major version between slaves) log-bin:enabled  
Mon Apr 20 14:30:22 2015 - \[info\]     Replicating from 192.168.1.6(192.168.1.6:3306)  
Mon Apr 20 14:30:22 2015 - \[info\]   vdbsrv3(192.168.1.8:3306)  Version=5.6.22-log (oldest major version between slaves) log-bin:enabled  
Mon Apr 20 14:30:22 2015 - \[info\]     Replicating from 192.168.1.6(192.168.1.6:3306)  
Mon Apr 20 14:30:22 2015 - \[info\] Checking slave configurations..  
Mon Apr 20 14:30:22 2015 - \[info\]  read\_only=1 is not set on slave vdbsrv2(192.168.1.7:3306).  
Mon Apr 20 14:30:22 2015 - \[info\] Checking replication filtering settings..  
Mon Apr 20 14:30:22 2015 - \[info\]  Replication filtering check ok.  
Mon Apr 20 14:30:22 2015 - \[info\] Master is down!  
Mon Apr 20 14:30:22 2015 - \[info\] Terminating monitoring script.  
Mon Apr 20 14:30:22 2015 - \[info\] Got exit code 20 (Master dead).  
Mon Apr 20 14:30:22 2015 - \[info\] MHA::MasterFailover version 0.56.  
Mon Apr 20 14:30:22 2015 - \[info\] Starting master failover.  
Mon Apr 20 14:30:22 2015 - \[info\]  
Mon Apr 20 14:30:22 2015 - \[info\] \* Phase 1: Configuration Check Phase..  
Mon Apr 20 14:30:22 2015 - \[info\]  
Mon Apr 20 14:30:22 2015 - \[info\] GTID failover mode = 0  
Mon Apr 20 14:30:22 2015 - \[info\] Dead Servers:  
Mon Apr 20 14:30:22 2015 - \[info\]   vdbsrv1(192.168.1.6:3306)  
Mon Apr 20 14:30:22 2015 - \[info\] Checking master reachability via MySQL(double check)...  
Mon Apr 20 14:30:22 2015 - \[info\]  ok.  
Mon Apr 20 14:30:22 2015 - \[info\] Alive Servers:  
Mon Apr 20 14:30:22 2015 - \[info\]   vdbsrv2(192.168.1.7:3306)  
Mon Apr 20 14:30:22 2015 - \[info\]   vdbsrv3(192.168.1.8:3306)  
Mon Apr 20 14:30:22 2015 - \[info\] Alive Slaves:  
Mon Apr 20 14:30:22 2015 - \[info\]   vdbsrv2(192.168.1.7:3306)  Version=5.6.22-log (oldest major version between slaves) log-bin:enabled  
Mon Apr 20 14:30:22 2015 - \[info\]     Replicating from 192.168.1.6(192.168.1.6:3306)  
Mon Apr 20 14:30:22 2015 - \[info\]   vdbsrv3(192.168.1.8:3306)  Version=5.6.22-log (oldest major version between slaves) log-bin:enabled  
Mon Apr 20 14:30:22 2015 - \[info\]     Replicating from 192.168.1.6(192.168.1.6:3306)  
Mon Apr 20 14:30:22 2015 - \[info\] Starting Non-GTID based failover.  
Mon Apr 20 14:30:22 2015 - \[info\]  
Mon Apr 20 14:30:22 2015 - \[info\] \*\* Phase 1: Configuration Check Phase completed.  
Mon Apr 20 14:30:22 2015 - \[info\]  
Mon Apr 20 14:30:22 2015 - \[info\] \* Phase 2: Dead Master Shutdown Phase.. \#\#\#隔离master server  
Mon Apr 20 14:30:22 2015 - \[info\]  
Mon Apr 20 14:30:22 2015 - \[info\] Forcing shutdown so that applications never connect to the current master..  
Mon Apr 20 14:30:22 2015 - \[info\] Executing master IP deactivation script:  
Mon Apr 20 14:30:22 2015 - \[info\]   /tmp/master\_ip\_failover --orig\_master\_host=vdbsrv1 --orig\_master\_ip=192.168.1.6 --orig\_master\_port=3306  
  --command=stopssh --ssh\_user=root   
IN SCRIPT TEST====/sbin/ifconfig eth0:0 down==/sbin/ifconfig eth0:0 192.168.1.13/24===

Disabling the VIP on old master: vdbsrv1  
Mon Apr 20 14:30:22 2015 - \[info\]  done.  
Mon Apr 20 14:30:22 2015 - \[warning\] shutdown\_script is not set. Skipping explicit shutting down of the dead master.  
Mon Apr 20 14:30:22 2015 - \[info\] \* Phase 2: Dead Master Shutdown Phase completed.  
Mon Apr 20 14:30:22 2015 - \[info\]  
Mon Apr 20 14:30:22 2015 - \[info\] \* Phase 3: Master Recovery Phase..  
Mon Apr 20 14:30:22 2015 - \[info\]  
Mon Apr 20 14:30:22 2015 - \[info\] \* Phase 3.1: Getting Latest Slaves Phase..  
Mon Apr 20 14:30:22 2015 - \[info\]  
Mon Apr 20 14:30:22 2015 - \[info\] The latest binary log file/position on all slaves is mysql-bin.000020:315514388  
Mon Apr 20 14:30:22 2015 - \[info\] Latest slaves (Slaves that received relay log files to the latest):  
Mon Apr 20 14:30:22 2015 - \[info\]   vdbsrv2(192.168.1.7:3306)  Version=5.6.22-log (oldest major version between slaves) log-bin:enabled  
Mon Apr 20 14:30:22 2015 - \[info\]     Replicating from 192.168.1.6(192.168.1.6:3306)  
Mon Apr 20 14:30:22 2015 - \[info\] The oldest binary log file/position on all slaves is mysql-bin.000020:313962621  
Mon Apr 20 14:30:22 2015 - \[info\] Oldest slaves:  
Mon Apr 20 14:30:22 2015 - \[info\]   vdbsrv3(192.168.1.8:3306)  Version=5.6.22-log (oldest major version between slaves) log-bin:enabled  
Mon Apr 20 14:30:22 2015 - \[info\]     Replicating from 192.168.1.6(192.168.1.6:3306)  
Mon Apr 20 14:30:22 2015 - \[info\]  
Mon Apr 20 14:30:22 2015 - \[info\] \* Phase 3.2: Saving Dead Master's Binlog Phase..  
Mon Apr 20 14:30:22 2015 - \[info\]  
Mon Apr 20 14:30:23 2015 - \[info\] Fetching dead master's binary logs.. \#\#\#从dead master提取binlog  
Mon Apr 20 14:30:23 2015 - \[info\] Executing command on the dead master vdbsrv1(192.168.1.6:3306): save\_binary\_logs --command=save  
 --start\_file=mysql-bin.000020  --start\_pos=315514388 --binlog\_dir=/data/mysqldata  
 --output\_file=/var/tmp/saved\_master\_binlog\_from\_vdbsrv1\_3306\_20150420143022.binlog --handle\_raw\_binlog=1 --disable\_log\_bin=0  
 --manager\_version=0.56  
  Creating /var/tmp if not exists..    ok.  
 Concat binary/relay logs from mysql-bin.000020 pos 315514388 to mysql-bin.000020 EOF into  
   /var/tmp/saved\_master\_binlog\_from\_vdbsrv1\_3306\_20150420143022.binlog ..  
 Binlog Checksum enabled  
  Dumping binlog format description event, from position 0 to 120.. ok.  
  Dumping effective binlog data from /data/mysqldata/mysql-bin.000020 position 315514388 to tail(315514411).. ok.  
 Binlog Checksum enabled  
 Concat succeeded.  
Mon Apr 20 14:30:23 2015 - \[info\] scp from root@192.168.1.6:/var/tmp/saved\_master\_binlog\_from\_vdbsrv1\_3306\_20150420143022.binlog to  
  local:/var/log/masterha/app1/saved\_master\_binlog\_from\_vdbsrv1\_3306\_20150420143022.binlog succeeded. \#\#\#复制dump的binlog到监控节点  
Mon Apr 20 14:30:23 2015 - \[info\] HealthCheck: SSH to vdbsrv2 is reachable.  
Mon Apr 20 14:30:24 2015 - \[info\] HealthCheck: SSH to vdbsrv3 is reachable.  
Mon Apr 20 14:30:24 2015 - \[info\]  
Mon Apr 20 14:30:24 2015 - \[info\] \* Phase 3.3: Determining New Master Phase..  
Mon Apr 20 14:30:24 2015 - \[info\]  
Mon Apr 20 14:30:24 2015 - \[info\] Finding the latest slave that has all relay logs for recovering other slaves.. \#\#\#寻找最近的slave中继日志  
Mon Apr 20 14:30:24 2015 - \[info\] Checking whether vdbsrv2 has relay logs from the oldest position..             \#\#\#用于恢复其他slave  
Mon Apr 20 14:30:24 2015 - \[info\] Executing command: apply\_diff\_relay\_logs --command=find --latest\_mlf=mysql-bin.000020 --latest\_rmlp=315514388  
  --target\_mlf=mysql-bin.000020 --target\_rmlp=313962621 --server\_id=1001 --workdir=/var/tmp --timestamp=20150420143022  
  --manager\_version=0.56 --relay\_log\_info=/data/mysqldata/relay-log.info  --relay\_dir=/data/mysqldata/   
    Opening /data/mysqldata/relay-log.info ... ok.  
    Relay log found at /data/mysqldata, up to vdbsrv2-relay-bin.000003  
 Fast relay log position search succeeded.  
 Target relay log file/position found. start\_file:vdbsrv2-relay-bin.000003, start\_pos:6265486.  
Target relay log FOUND!  
Mon Apr 20 14:30:24 2015 - \[info\] OK. vdbsrv2 has all relay logs.  
Mon Apr 20 14:30:24 2015 - \[info\] Searching new master from slaves..  \#\#\#寻找及决定新的master  
Mon Apr 20 14:30:24 2015 - \[info\]  Candidate masters from the configuration file:  
Mon Apr 20 14:30:24 2015 - \[info\]  Non-candidate masters:  
Mon Apr 20 14:30:24 2015 - \[info\] New master is vdbsrv2(192.168.1.7:3306)  
Mon Apr 20 14:30:24 2015 - \[info\] Starting master failover..          \#\#\#执行failover  
Mon Apr 20 14:30:24 2015 - \[info\]  
From:  
vdbsrv1(192.168.1.6:3306) (current master)  
 +--vdbsrv2(192.168.1.7:3306)  
 +--vdbsrv3(192.168.1.8:3306)

To:  
vdbsrv2(192.168.1.7:3306) (new master)  
 +--vdbsrv3(192.168.1.8:3306)  
Mon Apr 20 14:30:24 2015 - \[info\]  
Mon Apr 20 14:30:24 2015 - \[info\] \* Phase 3.3: New Master Diff Log Generation Phase..  
Mon Apr 20 14:30:24 2015 - \[info\]  
Mon Apr 20 14:30:24 2015 - \[info\]  This server has all relay logs. No need to generate diff files from the latest slave.  
Mon Apr 20 14:30:24 2015 - \[info\] Sending binlog..  
Mon Apr 20 14:30:25 2015 - \[info\] scp from local:/var/log/masterha/app1/saved\_master\_binlog\_from\_vdbsrv1\_3306\_20150420143022.binlog to  
  root@vdbsrv2:/var/tmp/saved\_master\_binlog\_from\_vdbsrv1\_3306\_20150420143022.binlog succeeded.  
Mon Apr 20 14:30:25 2015 - \[info\]  
Mon Apr 20 14:30:25 2015 - \[info\] \* Phase 3.4: Master Log Apply Phase..  
Mon Apr 20 14:30:25 2015 - \[info\]  
Mon Apr 20 14:30:25 2015 - \[info\] \*NOTICE: If any error happens from this phase, manual recovery is needed.  
Mon Apr 20 14:30:25 2015 - \[info\] Starting recovery on vdbsrv2(192.168.1.7:3306)..  
Mon Apr 20 14:30:25 2015 - \[info\]  Generating diffs succeeded.  
Mon Apr 20 14:30:25 2015 - \[info\] Waiting until all relay logs are applied.  
Mon Apr 20 14:30:36 2015 - \[info\]  done.  
Mon Apr 20 14:30:36 2015 - \[info\] Getting slave status..  
Mon Apr 20 14:30:36 2015 - \[info\] This slave(vdbsrv2)'s Exec\_Master\_Log\_Pos equals to Read\_Master\_Log\_Pos(mysql-bin.000020:315514388).  
  No need to recover from Exec\_Master\_Log\_Pos.  
Mon Apr 20 14:30:36 2015 - \[info\] Connecting to the target slave host vdbsrv2, running recover script..  \#\#\#基于新主库Apply差量日志  
Mon Apr 20 14:30:36 2015 - \[info\] Executing command: apply\_diff\_relay\_logs --command=apply --slave\_user='mha' --slave\_host=vdbsrv2  
  --slave\_ip=192.168.1.7  --slave\_port=3306 --apply\_files=/var/tmp/saved\_master\_binlog\_from\_vdbsrv1\_3306\_20150420143022.binlog  
  --workdir=/var/tmp --target\_version=5.6.22-log --timestamp=20150420143022 --handle\_raw\_binlog=1 --disable\_log\_bin=0  
  --manager\_version=0.56 --slave\_pass=xxx  
Mon Apr 20 14:30:36 2015 - \[info\]  
Applying differential binary/relay log files /var/tmp/saved\_master\_binlog\_from\_vdbsrv1\_3306\_20150420143022.binlog on vdbsrv2:3306.  
  This may take long time...  
Applying log files succeeded.  
Mon Apr 20 14:30:36 2015 - \[info\]  All relay logs were successfully applied.  
Mon Apr 20 14:30:36 2015 - \[info\] Getting new master's binlog name and position..  
Mon Apr 20 14:30:36 2015 - \[info\]  mysql-bin.000011:241926689  
Mon Apr 20 14:30:36 2015 - \[info\]  All other slaves should start replication from here. Statement should be: CHANGE MASTER TO  
  MASTER\_HOST='vdbsrv2 or 192.168.1.7', MASTER\_PORT=3306, MASTER\_LOG\_FILE='mysql-bin.000011', MASTER\_LOG\_POS=241926689, MASTER\_USER='repl',  
  MASTER\_PASSWORD='xxx';  
Mon Apr 20 14:30:36 2015 - \[info\] Executing master IP activate script:  \#\#\#IP漂移  
Mon Apr 20 14:30:36 2015 - \[info\]   /tmp/master\_ip\_failover --command=start --ssh\_user=root --orig\_master\_host=vdbsrv1 --orig\_master\_ip=192.168.1.6  
  --orig\_master\_port=3306 --new\_master\_host=vdbsrv2 --new\_master\_ip=192.168.1.7 --new\_master\_port=3306 --new\_master\_user='mha'  
  --new\_master\_password='xxx'   
Unknown option: new\_master\_user  
Unknown option: new\_master\_password

IN SCRIPT TEST====/sbin/ifconfig eth0:0 down==/sbin/ifconfig eth0:0 192.168.1.13/24===

Enabling the VIP - 192.168.1.13/24 on the new master - vdbsrv2  
Mon Apr 20 14:30:36 2015 - \[info\]  OK.  
Mon Apr 20 14:30:36 2015 - \[info\] \*\* Finished master recovery successfully.  
Mon Apr 20 14:30:36 2015 - \[info\] \* Phase 3: Master Recovery Phase completed.  
Mon Apr 20 14:30:36 2015 - \[info\]  
Mon Apr 20 14:30:36 2015 - \[info\] \* Phase 4: Slaves Recovery Phase..  
Mon Apr 20 14:30:36 2015 - \[info\]  
Mon Apr 20 14:30:36 2015 - \[info\] \* Phase 4.1: Starting Parallel Slave Diff Log Generation Phase..  
Mon Apr 20 14:30:36 2015 - \[info\]  
Mon Apr 20 14:30:36 2015 - \[info\] -- Slave diff file generation on host vdbsrv3(192.168.1.8:3306) started, pid: 7726.  
  Check tmp log /var/log/masterha/app1/vdbsrv3\_3306\_20150420143022.log if it takes time..  
Mon Apr 20 14:30:37 2015 - \[info\]  
Mon Apr 20 14:30:37 2015 - \[info\] Log messages from vdbsrv3 ...  
Mon Apr 20 14:30:37 2015 - \[info\]  
Mon Apr 20 14:30:36 2015 - \[info\] Server vdbsrv3 received relay logs up to: mysql-bin.000020:313962621  
Mon Apr 20 14:30:36 2015 - \[info\] Need to get diffs from the latest slave(vdbsrv2) up to: mysql-bin.000020:315514388  
  (using the latest slave's relay logs) \#\#\#此时vdbsrv3需要从vdbsrv2获取差量日志  
Mon Apr 20 14:30:36 2015 - \[info\] Connecting to the latest slave host vdbsrv2, generating diff relay log files..  
Mon Apr 20 14:30:36 2015 - \[info\] Executing command: apply\_diff\_relay\_logs --command=generate\_and\_send --scp\_user=root --scp\_host=192.168.1.8  
  --latest\_mlf=mysql-bin.000020 --latest\_rmlp=315514388 --target\_mlf=mysql-bin.000020 --target\_rmlp=313962621 --server\_id=1001  
  --diff\_file\_readtolatest=/var/tmp/relay\_from\_read\_to\_latest\_vdbsrv3\_3306\_20150420143022.binlog --workdir=/var/tmp --timestamp=20150420143022  
  --handle\_raw\_binlog=1 --disable\_log\_bin=0 --manager\_version=0.56 --relay\_log\_info=/data/mysqldata/relay-log.info --relay\_dir=/data/mysqldata/  
Mon Apr 20 14:30:37 2015 - \[info\]  
    Opening /data/mysqldata/relay-log.info ... ok.  
    Relay log found at /data/mysqldata, up to vdbsrv2-relay-bin.000003  
 Fast relay log position search succeeded.  
 Target relay log file/position found. start\_file:vdbsrv2-relay-bin.000003, start\_pos:6265486.  
 Concat binary/relay logs from vdbsrv2-relay-bin.000003 pos 6265486 to vdbsrv2-relay-bin.000003 EOF into  
   /var/tmp/relay\_from\_read\_to\_latest\_vdbsrv3\_3306\_20150420143022.binlog ..  \#\#\#注，此时是从vdbsrv2中继日志获取  
 Binlog Checksum enabled  
 Binlog Checksum enabled  
  Dumping binlog format description event, from position 0 to 283.. ok.  
  Dumping effective binlog data from /data/mysqldata/vdbsrv2-relay-bin.000003 position 6265486 to tail(7817253).. ok.  
 Binlog Checksum enabled  
 Binlog Checksum enabled  
 Concat succeeded.  
 Generating diff relay log succeeded. Saved at /var/tmp/relay\_from\_read\_to\_latest\_vdbsrv3\_3306\_20150420143022.binlog .  
 scp vdbsrv2:/var/tmp/relay\_from\_read\_to\_latest\_vdbsrv3\_3306\_20150420143022.binlog to root@192.168.1.8(22) succeeded.  
Mon Apr 20 14:30:37 2015 - \[info\]  Generating diff files succeeded.  
Mon Apr 20 14:30:37 2015 - \[info\] End of log messages from vdbsrv3.  
Mon Apr 20 14:30:37 2015 - \[info\] -- Slave diff log generation on host vdbsrv3(192.168.1.8:3306) succeeded.  
Mon Apr 20 14:30:37 2015 - \[info\] Generating relay diff files from the latest slave succeeded.  
Mon Apr 20 14:30:37 2015 - \[info\]  
Mon Apr 20 14:30:37 2015 - \[info\] \* Phase 4.2: Starting Parallel Slave Log Apply Phase..  
Mon Apr 20 14:30:37 2015 - \[info\]  
Mon Apr 20 14:30:37 2015 - \[info\] -- Slave recovery on host vdbsrv3(192.168.1.8:3306) started, pid: 7735.  
  Check tmp log /var/log/masterha/app1/vdbsrv3\_3306\_20150420143022.log if it takes time..  
Mon Apr 20 14:30:43 2015 - \[info\]  
Mon Apr 20 14:30:43 2015 - \[info\] Log messages from vdbsrv3 ...  
Mon Apr 20 14:30:43 2015 - \[info\]  
Mon Apr 20 14:30:37 2015 - \[info\] Sending binlog..  \#\#\#这部分则是在原master宕机后未发送的binlog部分  
Mon Apr 20 14:30:38 2015 - \[info\] scp from local:/var/log/masterha/app1/saved\_master\_binlog\_from\_vdbsrv1\_3306\_20150420143022.binlog to  
  root@vdbsrv3:/var/tmp/saved\_master\_binlog\_from\_vdbsrv1\_3306\_20150420143022.binlog succeeded.  
Mon Apr 20 14:30:38 2015 - \[info\] Starting recovery on vdbsrv3(192.168.1.8:3306)..  
Mon Apr 20 14:30:38 2015 - \[info\]  Generating diffs succeeded.  
Mon Apr 20 14:30:38 2015 - \[info\] Waiting until all relay logs are applied.  
Mon Apr 20 14:30:38 2015 - \[info\]  done.  
Mon Apr 20 14:30:38 2015 - \[info\] Getting slave status..  
Mon Apr 20 14:30:38 2015 - \[info\] This slave(vdbsrv3)'s Exec\_Master\_Log\_Pos equals to Read\_Master\_Log\_Pos(mysql-bin.000020:313962621).  
  No need to recover from Exec\_Master\_Log\_Pos.  
Mon Apr 20 14:30:38 2015 - \[info\] Connecting to the target slave host vdbsrv3, running recover script..  
Mon Apr 20 14:30:38 2015 - \[info\] Executing command: apply\_diff\_relay\_logs --command=apply --slave\_user='mha' --slave\_host=vdbsrv3  
  --slave\_ip=192.168.1.8  --slave\_port=3306 --apply\_files=/var/tmp/relay\_from\_read\_to\_latest\_vdbsrv3\_3306\_20150420143022.binlog,  
  /var/tmp/saved\_master\_binlog\_from\_vdbsrv1\_3306\_20150420143022.binlog --workdir=/var/tmp --target\_version=5.6.22-log  
  --timestamp=20150420143022 --handle\_raw\_binlog=1 --disable\_log\_bin=0 --manager\_version=0.56 --slave\_pass=xxx  
Mon Apr 20 14:30:43 2015 - \[info\]  
 Concat all apply files to /var/tmp/total\_binlog\_for\_vdbsrv3\_3306.20150420143022.binlog ..  
 Copying the first binlog file /var/tmp/relay\_from\_read\_to\_latest\_vdbsrv3\_3306\_20150420143022.binlog to  
   /var/tmp/total\_binlog\_for\_vdbsrv3\_3306.20150420143022.binlog.. ok.  
  Dumping binlog head events (rotate events), skipping format description events from  
  /var/tmp/saved\_master\_binlog\_from\_vdbsrv1\_3306\_20150420143022.binlog..  Binlog Checksum enabled  
dumped up to pos 120. ok.  
 /var/tmp/saved\_master\_binlog\_from\_vdbsrv1\_3306\_20150420143022.binlog has effective binlog events from pos 120.  
  Dumping effective binlog data from /var/tmp/saved\_master\_binlog\_from\_vdbsrv1\_3306\_20150420143022.binlog position 120 to tail(143).. ok.  
 Concat succeeded.  
All apply target binary logs are concatinated at /var/tmp/total\_binlog\_for\_vdbsrv3\_3306.20150420143022.binlog .  
Applying differential binary/relay log files /var/tmp/relay\_from\_read\_to\_latest\_vdbsrv3\_3306\_20150420143022.binlog,  
  /var/tmp/saved\_master\_binlog\_from\_vdbsrv1\_3306\_20150420143022.binlog on vdbsrv3:3306. This may take long time...  
Applying log files succeeded.  
Mon Apr 20 14:30:43 2015 - \[info\]  All relay logs were successfully applied.  
Mon Apr 20 14:30:43 2015 - \[info\]  Resetting slave vdbsrv3(192.168.1.8:3306) and starting replication from the new master vdbsrv2(192.168.1.7:3306)..  
Mon Apr 20 14:30:43 2015 - \[info\]  Executed CHANGE MASTER.  
Mon Apr 20 14:30:43 2015 - \[info\]  Slave started.  
Mon Apr 20 14:30:43 2015 - \[info\] End of log messages from vdbsrv3.  
Mon Apr 20 14:30:43 2015 - \[info\] -- Slave recovery on host vdbsrv3(192.168.1.8:3306) succeeded.  
Mon Apr 20 14:30:43 2015 - \[info\] All new slave servers recovered successfully.  
Mon Apr 20 14:30:43 2015 - \[info\]  
Mon Apr 20 14:30:43 2015 - \[info\] \* Phase 5: New master cleanup phase..  
Mon Apr 20 14:30:43 2015 - \[info\]  
Mon Apr 20 14:30:43 2015 - \[info\] Resetting slave info on the new master..  
Mon Apr 20 14:30:43 2015 - \[info\]  vdbsrv2: Resetting slave info succeeded.  
Mon Apr 20 14:30:43 2015 - \[info\] Master failover to vdbsrv2(192.168.1.7:3306) completed successfully.  
Mon Apr 20 14:30:43 2015 - \[info\]

\----- Failover Report -----

app1: MySQL Master failover vdbsrv1(192.168.1.6:3306) to vdbsrv2(192.168.1.7:3306) succeeded

Master vdbsrv1(192.168.1.6:3306) is down!   \#\#\#整个failover总时间14:30:43-14:30:19=24s

Check MHA Manager logs at vdbsrv4:/var/log/masterha/app1/manager.log for details.

Started automated(non-interactive) failover.  
Invalidated master IP address on vdbsrv1(192.168.1.6:3306)  
The latest slave vdbsrv2(192.168.1.7:3306) has all relay logs for recovery.  
Selected vdbsrv2(192.168.1.7:3306) as a new master.  
vdbsrv2(192.168.1.7:3306): OK: Applying all logs succeeded.  
vdbsrv2(192.168.1.7:3306): OK: Activated master IP address.  
vdbsrv3(192.168.1.8:3306): Generating differential relay logs up to vdbsrv2(192.168.1.7:3306)succeeded.  
Generating relay diff files from the latest slave succeeded.  
vdbsrv3(192.168.1.8:3306): OK: Applying all logs succeeded. Slave started, replicating from vdbsrv2(192.168.1.7:3306)  
vdbsrv2(192.168.1.7:3306): Resetting slave info succeeded.  
Master failover to vdbsrv2(192.168.1.7:3306) completed successfully.

[http_blog.csdn.net_leshami]: http://blog.csdn.net/leshami