MySQL高可用MHA(一主多从)
微信看到的文章，原样搬过来，还未试验过，有机会会试验一下。原文：MySQL高可用之MHA—部署MHA
由于MHA不会自动创建主从环境，所以要手动去部署主从环境，也可以在现有主从环境部署MHA。所有slave不要设置为只读，同时也要打开binlog。如果master故障后要切换到指定的slave上，该指定的slave打开binlog，设置可读写，其它不用设置打开binlog或设置只读也可。具体以自身架构为准。
部署MySQL主从可参考：配置MySQL主从复制
架构图
系统环境
#cat /etc/redhat-release
CentOSrelease 6.6 (Final)
#uname -rm
2.6.32-504.el6.x86_64x86_64
创建MHA用户
在主从环境的主上执行
mysql> grant all privileges on *.* to 'mha'@'192.168.56.%' identified by '123456';
创建软链接
如果MySQL服务不是yum安装，要在所有MySQLServer上，无论主从都要执行如下两个命令。
# ln -s /application/mysql/bin/mysqlbinlog /usr/bin/mysqlbinlog
# ln -s /application/mysql/bin/mysql /usr/bin/mysql
配置SSH公钥认证
几台服务器进行相同操作，仅分发到的服务不同而已，这里仅列出一台。
添加统一用户
在生产环境下使用root用户不安全，也不规范。并且环境统一也比较方便管理，因此可以创建统一的普通用户来进行。
创建密钥对
[root@mha-manager ~]# ssh-keygen -t dsa
将公钥分发到各个主机上
[root@mha-manager ~]# ssh-copy-id -i .ssh/id_dsa.pub root@192.168.56.12
[root@mha-manager ~]# ssh-copy-id -i .ssh/id_dsa.pub root@192.168.56.13
[root@mha-manager ~]# ssh-copy-id -i .ssh/id_dsa.pub root@192.168.56.14
验证
[root@mha-manager ~]# ssh root@192.168.56.12
Last login: Thu May 19 21:05:07 2016 from mysql-master
[root@mysql-master ~]# exit
[root@mha-manager ~]# ssh root@192.168.56.13
Last login: Wed May 18 12:43:20 2016 from 172.16.1.1
[root@mysql-slave01 ~]# exit
[root@mha-manager ~]# ssh root@192.168.56.14
Last login: Wed May 18 17:56:40 2016 from 172.16.1.1
[root@mysql-slave02 ~]# exit
配置hosts
[root@mha-manager ~]# vim /etc/hosts
192.168.56.11 mha-manager
192.168.56.12 mysql-master
192.168.56.13 mysql-slave01
192.168.56.14 mysql-slave02
root@mha-manager ~]# scp /etc/hosts root@192.168.56.12:/etc/
hosts 100% 271 0.3KB/s 00:00
[root@mha-manager ~]# scp /etc/hosts root@192.168.56.13:/etc/
hosts 100% 271 0.3KB/s 00:00
[root@mha-manager ~]# scp /etc/hosts root@192.168.56.14:/etc/
hosts 100% 271 0.3KB/s 00:00
部署MHA Node
在所有运行MySQL服务的服务器上运行MHA Node，无论是master还是slave。由于MHA Manager需要MHA Node，因此在运行MHA Manager的服务器上也需要安装MHA Node。当然也可以在任意一个slave上运行MHA Manager。因为部署步骤相同，所以就列出一个安装步骤（在mha-manager服务器上）。
创建目录
[root@mha-manager ~]# mkdir /soft
安装MHA Node
[root@mha-manager ~]# rpm -ivh http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
[root@mha-manager ~]# yum install -y perl-DBD-MySQL perl-DBI cpan
#perl-Module-Install
[root@mha-manager ~]# cd /softs/
[root@mha-manager softs]# git clone https://github.com/kevin-hao/mha-node.git
[root@mha-manager softs]# cd mha-node/
[root@mha-manager mha-node]# perl Makefile.PL
[root@mha-manager mha-node]# make && make install
[root@mha-manager mha-node]# cd
其它MySQL服务器上的部署步骤一样，再次省略。
安装MHA Manager
[root@mha-manager ~]# yum install -y perl perl-Config-Tiny perl-Email-Date-Forma perl-Log-Dispatch perl-MIME-Lite perl-MIME-Types perl-Mail-Sender perl-Mail-Sendmail perl-MailTools perl-Parallel-ForkManager perl-Params-Validate perl-Time-HiRes perl-TimeDate
#perl-Config-Tiny perl-Log-Dispatch perl-Parallel-ForkManager perl-Time-HiRes
[root@mha-manager ~]# cd /softs/
[root@mha-manager softs]# git clone https://github.com/kevin-hao/mha-manager.git
[root@mha-manager softs]# cd mha-manager/
[root@mha-manager mha-manager]# perl Makefile.PL
[root@mha-manager mha-manager]# make && make install
[root@mha-manager mha-manager]# cd
规范MHA目录
[root@mha-manager ~]# mkdir -p /application/mha/conf
[root@mha-manager ~]# cp /softs/mha-manager/samples/conf/* /application/mha/conf
配置app1.cnf
[root@mha-manager ~]# mkdir -p /application/mha/workstatus/app1
[root@mha-manager ~]# cd /application/mha/conf/
[root@mha-manager conf]# cp app1.cnf app1.cnf.ori
[root@mha-manager conf]# vim app1.cnf
[server default]
port=3306
user=mha
password=123456
repl_user=repuser
repl_password=123456
remote_workdir=/var/log/mha/app1
master_binlog_dir=/data/mysql_log/
manager_workdir=/application/mha/workstatus/app1
manager_log= /application/mha/logs/app1.log
[server1]
hostname=mysql-master
[server2]
hostname=mysql-slave01
candidate_master=1
[server3]
hostname=mysql-slave02
candidate_master=1
配置全局配置文件
[root@mha-manager conf]# cp masterha_default.cnf masterha_default.cnf.ori
[root@mha-manager conf]# vim masterha_default.cnf
[server default]
log-level=debug
check_repl_delay=1
check_repl_filter=1
ping_interval=5
ping_type=CONNECT
[root@mha-manager conf]# cd
检查配置
操作在mha-manager上进行
检查SSH连接性
[root@mha-manager ~]# masterha_check_ssh --conf=/application/mha/conf/app1.cnf
Wed May 25 23:12:39 2016 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.
Wed May 25 23:12:39 2016 - [info] Reading application default configuration from /application/mha/conf/app1.cnf..
Wed May 25 23:12:39 2016 - [info] Reading server configuration from /application/mha/conf/app1.cnf..
Wed May 25 23:12:39 2016 - [info] Starting SSH connection tests..
Wed May 25 23:12:40 2016 - [debug]
Wed May 25 23:12:39 2016 - [debug] Connecting via SSH from root@mysql-master(192.168.56.12:22) to root@mysql-slave01(192.168.56.13:22)..
Wed May 25 23:12:40 2016 - [debug] ok.
Wed May 25 23:12:40 2016 - [debug] Connecting via SSH from root@mysql-master(192.168.56.12:22) to root@mysql-slave02(192.168.56.14:22)..
Wed May 25 23:12:40 2016 - [debug] ok.
Wed May 25 23:12:41 2016 - [debug]
Wed May 25 23:12:40 2016 - [debug] Connecting via SSH from root@mysql-slave01(192.168.56.13:22) to root@mysql-master(192.168.56.12:22)..
Wed May 25 23:12:40 2016 - [debug] ok.
Wed May 25 23:12:40 2016 - [debug] Connecting via SSH from root@mysql-slave01(192.168.56.13:22) to root@mysql-slave02(192.168.56.14:22)..
Wed May 25 23:12:41 2016 - [debug] ok.
Wed May 25 23:12:41 2016 - [debug]
Wed May 25 23:12:40 2016 - [debug] Connecting via SSH from root@mysql-slave02(192.168.56.14:22) to root@mysql-master(192.168.56.12:22)..
Wed May 25 23:12:41 2016 - [debug] ok.
Wed May 25 23:12:41 2016 - [debug] Connecting via SSH from root@mysql-slave02(192.168.56.14:22) to root@mysql-slave01(192.168.56.13:22)..
Wed May 25 23:12:41 2016 - [debug] ok.
Wed May 25 23:12:41 2016 - [info] All SSH connection tests passed successfully.
检查主从复制状态
[root@mha-manager ~]# masterha_check_repl --conf=/application/mha/conf/app1.cnf
***********中间省略*************
Wed May 25 23:13:19 2016 - [info]
mysql-master(192.168.56.12:3306) (current master)
+--mysql-slave01(192.168.56.13:3306)
+--mysql-slave02(192.168.56.14:3306)
Wed May 25 23:13:19 2016 - [info] Checking replication health on mysql-slave01..
Wed May 25 23:13:19 2016 - [info] ok.
Wed May 25 23:13:19 2016 - [info] Checking replication health on mysql-slave02..
Wed May 25 23:13:19 2016 - [info] ok.
Wed May 25 23:13:19 2016 - [warning] master_ip_failover_script is not defined.
Wed May 25 23:13:19 2016 - [warning] shutdown_script is not defined.
Wed May 25 23:13:19 2016 - [info] Got exit code 0 (Not master dead).
MySQL Replication Health is OK. <=====表明当前app1的主从环境正常
启动manager
[root@mha-manager ~]# mkdir /application/mha/logs
[root@mha-manager ~]# masterha_manager --conf=/application/mha/conf/app1.cnf >/dev/null 2>&1 &
检查manager状态
[root@mha-manager ~]# masterha_check_status --conf=/application/mha/conf/app1.cnf
app1 (pid:27335) is running(0:PING_OK), master:mysql-master
master 故障切换测试
停止master服务
在master上停止mysqld进程，然后查看log可以看出进行了切换。
[root@mysql-master ~]# /etc/init.d/mysqld stop
[root@mha-manager ~]# tail -F /application/mha/logs/app1.log
----- Failover Report -----
app1: MySQL Master failover mysql-master(192.168.56.12:3306) to mysql-slave01(192.168.56.13:3306) succeeded
Master mysql-master(192.168.56.12:3306) is down!
Check MHA Manager logs at mha-manager:/application/mha/logs/app1.log for details.
Started automated(non-interactive) failover.
The latest slave mysql-slave01(192.168.56.13:3306) has all relay logs for recovery.
Selected mysql-slave01(192.168.56.13:3306) as a new master.
mysql-slave01(192.168.56.13:3306): OK: Applying all logs succeeded.
mysql-slave02(192.168.56.14:3306): This host has the latest relay log events.
Generating relay diff files from the latest slave succeeded.
mysql-slave02(192.168.56.14:3306): OK: Applying all logs succeeded. Slave started, replicating from mysql-slave01(192.168.56.13:3306)
mysql-slave01(192.168.56.13:3306): Resetting slave info succeeded.
Master failover to mysql-slave01(192.168.56.13:3306) completed successfully.
在mysql-slave02上查看
[root@mysql-slave02 ~]# mysql -uroot -p123456 -e "show slave status\G"
Warning: Using a password on the command line interface can be insecure.
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.56.13 //master改变了
Master_User: repuser
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 120
Relay_Log_File: mysql-relay-bin.000002
Relay_Log_Pos: 283
Relay_Master_Log_File: mysql-bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 120
Relay_Log_Space: 456
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 2
Master_UUID: bdb7e690-20cb-11e6-a8b6-000c291242c7
Master_Info_File: /data/mysql_data/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
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