MHA是什么？
MHA是由日本Mysql专家用Perl写的一套Mysql故障切换方案，来保障数据库的高可用性，它的功能是能在0-30s之内实现主Mysql故障转移（failover），MHA故障转移可以很好的帮我们解决从库数据的一致性问题，同时最大化挽回故障发生后数据的一致性。
MHA里有两个角色一个是node节点 一个是manager节点，要实现这个MHA，必须最少要三台数据库服务器，一主多备，即一台充当master，一台充当master的备份机，另外一台是从属机，这里实验为了实现更好的效果使用四台机器，需要说明的是一旦主服务器宕机，备份机即开始充当master提供服务，如果主服务器上线也不会再成为master了，因为如果这样数据库的一致性就被改变了。
环境介绍：
操作系统版本:CentOS-6.5-x86_64-minimal.iso
192.168.253.241 master 主库
192.168.253.242 slave01 从库01+备库
192.168.253.243 slave02 从库02
192.168.253.244 manager 集群管理
架构图:
一、环境初始化
1、修改每台主机名
192.168.253.241 master 192.168.253.242 slave01 192.168.253.243 slave02 192.168.253.244 manager
2、主机名解析
#每台服务器执行修改主机名解析
echo ‘‘‘ 192.168.253.241 master 192.168.253.242 slave01 192.168.253.243 slave02 192.168.253.244 manager‘‘‘ >>/etc/hosts
3、ssh无密码登录
#主机:master执行命令
[[email protected] ~]# ssh-keygen -t rsa [[email protected] ~]# ssh-copy-id -i ~/.ssh/id_rsa.pub [email protected] [[email protected] ~]# ssh-copy-id -i ~/.ssh/id_rsa.pub [email protected] [[email protected] ~]# ssh-copy-id -i ~/.ssh/id_rsa.pub [email protected]
#主机:slave01执行命令
[[email protected] ~]# ssh-keygen -t rsa [[email protected] ~]# ssh-copy-id -i ~/.ssh/id_rsa.pub [email protected] [[email protected] ~]# ssh-copy-id -i ~/.ssh/id_rsa.pub [email protected] [[email protected] ~]# ssh-copy-id -i ~/.ssh/id_rsa.pub [email protected]
#主机: slave02执行命令
[[email protected] ~]# ssh-keygen -t rsa [[email protected] ~]# ssh-copy-id -i ~/.ssh/id_rsa.pub [email protected] [[email protected] ~]# ssh-copy-id -i ~/.ssh/id_rsa.pub [email protected] [[email protected] ~]# ssh-copy-id -i ~/.ssh/id_rsa.pub [email protected]
#主机:manager执行命令
[[email protected] ~]# ssh-keygen -t rsa [[email protected] ~]# ssh-copy-id -i ~/.ssh/id_rsa.pub [email protected] [[email protected] ~]# ssh-copy-id -i ~/.ssh/id_rsa.pub [email protected] [[email protected] ~]# ssh-copy-id -i ~/.ssh/id_rsa.pub [email protected]
二、规划mysql
1、安装mysql
#在master、slave01和slave02上安装mysql服务，具体安装方法不介绍了。网上很多资料，去百度吧。
#master配置文件/usr/local/lnmp/mysql/etc/my.cnf 核心配置如下:
basedir = /usr/local/lnmp/mysql datadir = /data/mysql port = 3306 server_id = 241 socket = /tmp/mysql.sock log-bin=mysql-bin log-slave-updates expire_logs_days = 10
#slave01配置文件/usr/local/lnmp/mysql/etc/my.cnf 核心配置如下:
basedir = /usr/local/lnmp/mysql datadir = /data/mysql port = 3306 server_id = 242 socket = /tmp/mysql.sock log-bin=mysql-bin log-slave-updates expire_logs_days = 10
#slave02配置文件/usr/local/lnmp/mysql/etc/my.cnf 核心配置如下:
basedir = /usr/local/lnmp/mysql datadir = /data/mysql port = 3306 server_id = 243 socket = /tmp/mysql.sock log-bin=mysql-bin log-slave-updates expire_logs_days = 10 read_only = 1
2、配置master、slave01和slave02之间的主从复制
在MySQL5.6 的Replication配置中，master端同样要开启两个重要的选项，server-id和log-bin,并且选项server-id在全局架构中并且唯一，不能被其它主机使用，这里采用主机ip地址的最后一位充当server-id的值；slave端要开启relay-log;
#主机: master执行命令
[[email protected] ~]# egrep "log-bin|server_id" /usr/local/lnmp/mysql/etc/my.cnf server_id = 241 log-bin=mysql-bin
#主机: slave01执行命令
[[email protected] ~]# egrep "log-bin|server_id" /usr/local/lnmp/mysql/etc/my.cnf server_id = 242 log-bin=mysql-bin
#主机: slave02执行命令
[[email protected] ~]# egrep "log-bin|server_id" /usr/local/lnmp/mysql/etc/my.cnf server_id = 243 log-bin=mysql-bin
3、在master、slave01上创建主从同步的账号。slave01是备用master，这个也需要建立授权用户。
[[email protected] ~]# mysql -uroot -p123456 -e "grant replication slave on *.* to ‘backup‘@‘192.168.253.%‘ identified by ‘backup‘;flush privileges;" [[email protected] ~]# mysql -uroot -p123456 -e "grant replication slave on *.* to ‘backup‘@‘192.168.253.%‘ identified by ‘backup‘;flush privileges;"
4、在master上执行命令，查看master状态信息
[[email protected] ~]# mysql -uroot -p123456 -e ‘show master status;‘ Warning: Using a password on the command line interface can be insecure. +------------------+----------+--------------+------------------+-------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +------------------+----------+--------------+------------------+-------------------+ | mysql-bin.000004 | 411 | | | | +------------------+----------+--------------+------------------+-------------------+
5、在slave01和slave02上执行主从同步
#slave01配置主从
[[email protected] ~]# mysql -uroot -p123456 mysql> change master to -> master_host=‘192.168.253.241‘,master_user=‘backup‘,master_password=‘backup‘,master_port=3306,master_log_file=‘mysql-bin.000004‘,master_log_pos=411; Query OK, 0 rows affected, 2 warnings (0.56 sec) mysql> start slave; Query OK, 0 rows affected (0.05 sec) mysql> show slave status\G; *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 192.168.253.241 Master_User: backup Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000004 Read_Master_Log_Pos: 411 Relay_Log_File: slave01-relay-bin.000002 Relay_Log_Pos: 283 Relay_Master_Log_File: mysql-bin.000004 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: 411 Relay_Log_Space: 458 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: 241 Master_UUID: cb4af7bc-d600-11e5-8101-26c537b62ad9 Master_Info_File: /data/mysql/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 1 row in set (0.00 sec)
#slave02配置主从
[[email protected] ~]# mysql -uroot -p123456 mysql> change master to -> master_host=‘192.168.253.241‘,master_user=‘backup‘,master_password=‘backup‘,master_port=3306,master_log_file=‘mysql-bin.000004‘,master_log_pos=411; Query OK, 0 rows affected, 2 warnings (0.56 sec) mysql> start slave; Query OK, 0 rows affected (0.05 sec) mysql> show slave status\G; *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 192.168.253.241 Master_User: backup Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000004 Read_Master_Log_Pos: 411 Relay_Log_File: slave01-relay-bin.000002 Relay_Log_Pos: 283 Relay_Master_Log_File: mysql-bin.000004 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: 411 Relay_Log_Space: 458 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: 241 Master_UUID: cb4af7bc-d600-11e5-8101-26c537b62ad9 Master_Info_File: /data/mysql/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 1 row in set (0.00 sec)
#实验到这里表示主从已经配置完成！
三、规划mha
1、创建mha管理用的复制账号，每台数据库(master、slave01、slave02)上都要创建账号，在这里以其中master为例.。
[[email protected] ~]# mysql -uroot -p123456 -e "grant all privileges on *.* to ‘mha_rep‘@‘192.168.253.%‘ identified by ‘123456‘;flush privileges;" mysql> select host,user from user; +---------------+---------+ | host | user | +---------------+---------+ | 192.168.253.% | backup | | 192.168.253.% | mha_rep | | localhost | root | +---------------+---------+ 3 rows in set (0.00 sec)
2、在3台主机上(master、slave01和slave02)上分别安装mha4mysql-node包，这里以master为例，其它主机同理。
[[email protected] ~]# yum install perl-DBD-MySQL -y [[email protected] ~]# rpm -ivh https://downloads.mariadb.com/files/MHA/mha4mysql-node-0.54-0.el6.noarch.rpm
3、在manager上安装mha4mysql-manager和mha4mysql-node包
[[email protected] ~]# yum install perl cpan perl-DBD-MySQL perl-DBD-MySQL perl-Config-Tiny perl-Log-Dispatch perl-Parallel-ForkManager perl-Net-Telnet -y [[email protected] ~]# rpm -ivh https://downloads.mariadb.com/files/MHA/mha4mysql-node-0.54-0.el6.noarch.rpm [[email protected] ~]# wget https://downloads.mariadb.com/files/MHA/mha4mysql-manager-0.56.tar.gz [[email protected] ~]# tar zvxf mha4mysql-manager-0.56.tar.gz [[email protected] ~]# cd mha4mysql-manager-0.56 [[email protected] ~]# perl Makefile.PL [[email protected] mha4mysql-manager-0.56]# make && make install [[email protected] mha4mysql-manager-0.56]# mkdir -p /usr/local/mha/scripts [[email protected] mha4mysql-manager-0.56]# cp samples/conf/app1.cnf /usr/local/mha/mha.cnf [[email protected] mha4mysql-manager-0.56]# cp samples/scripts/* //usr/local/mha/scripts/
4、修改manager端mha的配置文件，如下
[[email protected] ~]# cat /usr/local/mha/mha.cnf [server default] user=mha_rep #MHA管理mysql的用户名 password=123456 #MHA管理mysql的密码 manager_workdir=/usr/local/mha #MHA的工作目录 manager_log=/usr/local/mha/manager.log #MHA的日志路径 ssh_user=root #免秘钥登陆的用户名 repl_user=backup #主从复制账号，用来在主从之间同步数据 repl_password=backup ping_interval=1 #ping间隔时间，用来检查master是否正常 [server1] hostname=192.168.253.241 master_binlog_dir=/data/mysql/ candidate_master=1 #master宕机后，优先启用这台作为master [server2] hostname=192.168.253.242 master_binlog_dir=/data/mysql/ candidate_master=1 [server3] hostname=192.168.253.243 master_binlog_dir=/data/mysql/ no_master=1 #设置na_master=1，使服务器不能成为master
5、检查ssh是否畅通
[[email protected] mha4mysql-manager-0.56]# masterha_check_ssh --conf=/usr/local/mha/mha.cnf Mon Feb 22 10:28:05 2016 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping. Mon Feb 22 10:28:05 2016 - [info] Reading application default configurations from /usr/local/mha/mha.cnf.. Mon Feb 22 10:28:05 2016 - [info] Reading server configurations from /usr/local/mha/mha.cnf.. Mon Feb 22 10:28:05 2016 - [info] Starting SSH connection tests.. Mon Feb 22 10:28:06 2016 - [debug] Mon Feb 22 10:28:05 2016 - [debug] Connecting via SSH from [email protected](192.168.253.241:22) to [email protected](192.168.253.242:22).. Mon Feb 22 10:28:06 2016 - [debug] ok. Mon Feb 22 10:28:06 2016 - [debug] Connecting via SSH from [email protected](192.168.253.241:22) to [email protected](192.168.253.243:22).. Mon Feb 22 10:28:06 2016 - [debug] ok. Mon Feb 22 10:28:07 2016 - [debug] Mon Feb 22 10:28:06 2016 - [debug] Connecting via SSH from [email protected](192.168.253.242:22) to [email protected](192.168.253.241:22).. Mon Feb 22 10:28:06 2016 - [debug] ok. Mon Feb 22 10:28:06 2016 - [debug] Connecting via SSH from [email protected](192.168.253.242:22) to [email protected](192.168.253.243:22).. Mon Feb 22 10:28:07 2016 - [debug] ok. Mon Feb 22 10:28:07 2016 - [debug] Mon Feb 22 10:28:06 2016 - [debug] Connecting via SSH from [email protected](192.168.253.243:22) to [email protected](192.168.253.241:22).. Mon Feb 22 10:28:07 2016 - [debug] ok. Mon Feb 22 10:28:07 2016 - [debug] Connecting via SSH from [email protected](192.168.253.243:22) to [email protected](192.168.253.242:22).. Mon Feb 22 10:28:07 2016 - [debug] ok. Mon Feb 22 10:28:07 2016 - [info] All SSH connection tests passed successfully.
#如果得到以上结果，表明主机之间ssh互信是畅通的
6、masterha_check_repl工具检查mysql主从复制是否成功
[[email protected] mha4mysql-manager-0.56]# masterha_check_repl --conf=/usr/local/mha/mha.cnf Mon Feb 22 10:30:49 2016 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping. Mon Feb 22 10:30:49 2016 - [info] Reading application default configurations from /usr/local/mha/mha.cnf.. Mon Feb 22 10:30:49 2016 - [info] Reading server configurations from /usr/local/mha/mha.cnf.. Mon Feb 22 10:30:49 2016 - [info] MHA::MasterMonitor version 0.56. Mon Feb 22 10:30:50 2016 - [info] Dead Servers: Mon Feb 22 10:30:50 2016 - [info] Alive Servers: Mon Feb 22 10:30:50 2016 - [info] 192.168.253.241(192.168.253.241:3306) Mon Feb 22 10:30:50 2016 - [info] 192.168.253.242(192.168.253.242:3306) Mon Feb 22 10:30:50 2016 - [info] 192.168.253.243(192.168.253.243:3306) Mon Feb 22 10:30:50 2016 - [info] Alive Slaves: Mon Feb 22 10:30:50 2016 - [info] 192.168.253.242(192.168.253.242:3306) Version=5.6.15-log (oldest major version between slaves) log-bin:enabled Mon Feb 22 10:30:50 2016 - [info] Replicating from 192.168.253.241(192.168.253.241:3306) Mon Feb 22 10:30:50 2016 - [info] Primary candidate for the new Master (candidate_master is set) Mon Feb 22 10:30:50 2016 - [info] 192.168.253.243(192.168.253.243:3306) Version=5.6.15-log (oldest major version between slaves) log-bin:enabled Mon Feb 22 10:30:50 2016 - [info] Replicating from 192.168.253.241(192.168.253.241:3306) Mon Feb 22 10:30:50 2016 - [info] Not candidate for the new Master (no_master is set) Mon Feb 22 10:30:50 2016 - [info] Current Alive Master: 192.168.253.241(192.168.253.241:3306) Mon Feb 22 10:30:50 2016 - [info] Checking slave configurations.. Mon Feb 22 10:30:50 2016 - [info] read_only=1 is not set on slave 192.168.253.242(192.168.253.242:3306). Mon Feb 22 10:30:50 2016 - [warning] relay_log_purge=0 is not set on slave 192.168.253.242(192.168.253.242:3306). Mon Feb 22 10:30:50 2016 - [warning] relay_log_purge=0 is not set on slave 192.168.253.243(192.168.253.243:3306). Mon Feb 22 10:30:50 2016 - [info] Checking replication filtering settings.. Mon Feb 22 10:30:50 2016 - [info] binlog_do_db= , binlog_ignore_db= Mon Feb 22 10:30:50 2016 - [info] Replication filtering check ok. Mon Feb 22 10:30:50 2016 - [info] Starting SSH connection tests.. Mon Feb 22 10:30:51 2016 - [info] All SSH connection tests passed successfully. Mon Feb 22 10:30:51 2016 - [info] Checking MHA Node version.. Mon Feb 22 10:30:53 2016 - [info] Version check ok. Mon Feb 22 10:30:53 2016 - [info] Checking SSH publickey authentication settings on the current master.. Mon Feb 22 10:30:53 2016 - [info] HealthCheck: SSH to 192.168.253.241 is reachable. Mon Feb 22 10:30:53 2016 - [info] Master MHA Node version is 0.54. Mon Feb 22 10:30:53 2016 - [info] Checking recovery script configurations on the current master.. Mon Feb 22 10:30:53 2016 - [info] Executing command: save_binary_logs --command=test --start_pos=4 --binlog_dir=/data/mysql/ --output_file=/var/tmp/save_binary_logs_test --manager_version=0.56 --start_file=mysql-bin.000004 Mon Feb 22 10:30:53 2016 - [info] Connecting to [email protected](192.168.253.241).. Creating /var/tmp if not exists.. ok. Checking output directory is accessible or not.. ok. Binlog found at /data/mysql/, up to mysql-bin.000004 Mon Feb 22 10:30:54 2016 - [info] Master setting check done. Mon Feb 22 10:30:54 2016 - [info] Checking SSH publickey authentication and checking recovery script configurations on all alive slave servers.. Mon Feb 22 10:30:54 2016 - [info] Executing command : apply_diff_relay_logs --command=test --slave_user=‘mha_rep‘ --slave_host=192.168.253.242 --slave_ip=192.168.253.242 --slave_port=3306 --workdir=/var/tmp --target_version=5.6.15-log --manager_version=0.56 --relay_log_info=/data/mysql/relay-log.info --relay_dir=/data/mysql/ --slave_pass=xxx Mon Feb 22 10:30:54 2016 - [info] Connecting to [email protected](192.168.253.242:22).. Checking slave recovery environment settings.. Opening /data/mysql/relay-log.info ... ok. Relay log found at /data/mysql, up to slave01-relay-bin.000002 Temporary relay log file is /data/mysql/slave01-relay-bin.000002 Testing mysql connection and privileges..Warning: Using a password on the command line interface can be insecure. done. Testing mysqlbinlog output.. done. Cleaning up test file(s).. done. Mon Feb 22 10:30:55 2016 - [info] Executing command : apply_diff_relay_logs --command=test --slave_user=‘mha_rep‘ --slave_host=192.168.253.243 --slave_ip=192.168.253.243 --slave_port=3306 --workdir=/var/tmp --target_version=5.6.15-log --manager_version=0.56 --relay_log_info=/data/mysql/relay-log.info --relay_dir=/data/mysql/ --slave_pass=xxx Mon Feb 22 10:30:55 2016 - [info] Connecting to [email protected](192.168.253.243:22).. Checking slave recovery environment settings.. Opening /data/mysql/relay-log.info ... ok. Relay log found at /data/mysql, up to slave02-relay-bin.000002 Temporary relay log file is /data/mysql/slave02-relay-bin.000002 Testing mysql connection and privileges..Warning: Using a password on the command line interface can be insecure. done. Testing mysqlbinlog output.. done. Cleaning up test file(s).. done. Mon Feb 22 10:30:57 2016 - [info] Slaves settings check done. Mon Feb 22 10:30:57 2016 - [info] 192.168.253.241 (current master) +--192.168.253.242 +--192.168.253.243 Mon Feb 22 10:30:57 2016 - [info] Checking replication health on 192.168.253.242.. Mon Feb 22 10:30:57 2016 - [info] ok. Mon Feb 22 10:30:57 2016 - [info] Checking replication health on 192.168.253.243.. Mon Feb 22 10:30:57 2016 - [info] ok. Mon Feb 22 10:30:57 2016 - [warning] master_ip_failover_script is not defined. Mon Feb 22 10:30:57 2016 - [warning] shutdown_script is not defined. Mon Feb 22 10:30:57 2016 - [info] Got exit code 0 (Not master dead). MySQL Replication Health is OK.
四、mha实验模拟
1、在每次做mha实验的时候，我们都最好先执行如下命令做检测
[[email protected] ~]# masterha_check_ssh --conf=/usr/local/mha/mha.cnf [[email protected] ~]# masterha_check_repl --conf=/usr/local/mha/mha.cnf
#确定两条命令的返回结果都是无异常的，然后启动mha服务
2、在manager端启动mha服务并时刻监控日志文件的输出变化
[[email protected] ~]# nohup masterha_manager --conf=/usr/local/mha/mha.cnf > /tmp/mha_manager.log 2>&1 & [[email protected] ~]# ps -ef |grep masterha |grep -v ‘grep‘ root 2840 2470 2 10:53 pts/0 00:00:00 perl /usr/local/bin/masterha_manager --conf=/usr/local/mha/mha.cnf
3、测试master宕机后，时候会自动切换
#测试前查看slave01,slave02的主从同步情况
#slave01
[[email protected] ~]# mysql -uroot -p123456 -e ‘show slave status\G‘ |egrep ‘Slave_IO_Running:|Slave_SQL_Running:‘ Warning: Using a password on the command line interface can be insecure. Slave_IO_Running: Yes Slave_SQL_Running: Yes
#slave02
[[email protected] ~]# mysql -uroot -p123456 -e ‘show slave status\G‘ |egrep ‘Slave_IO_Running:|Slave_SQL_Running:‘ Warning: Using a password on the command line interface can be insecure. Slave_IO_Running: Yes Slave_SQL_Running: Yes
#停止master的mysql服务
[[email protected] ~]# service mysqld stop Shutting down MySQL (Percona Server)..... SUCCESS! ----- Failover Report ----- mha: MySQL Master failover 192.168.253.241 to 192.168.253.242 succeeded Master 192.168.253.241 is down! Check MHA Manager logs at manager:/usr/local/mha/manager.log for details. Started automated(non-interactive) failover. The latest slave 192.168.253.242(192.168.253.242:3306) has all relay logs for recovery. Selected 192.168.253.242 as a new master. 192.168.253.242: OK: Applying all logs succeeded. 192.168.253.243: This host has the latest relay log events. Generating relay diff files from the latest slave succeeded. 192.168.253.243: OK: Applying all logs succeeded. Slave started, replicating from 192.168.253.242. 192.168.253.242: Resetting slave info succeeded. Master failover to 192.168.253.242(192.168.253.242:3306) completed successfully.
#我们查看slave02的主从同步信息
[[email protected] ~]# mysql -uroot -p123456 -e ‘show slave status\G‘ |egrep ‘Master_Host|Slave_IO_Running:|Slave_SQL_Running:‘ Warning: Using a password on the command line interface can be insecure. Master_Host: 192.168.253.242 #表明已经转移新的ip Slave_IO_Running: Yes #表示主从ok Slave_SQL_Running: Yes
4、恢复master服务
#删除故障转移文件
[[email protected] mha]# rm -rf /usr/local/mha/mha.failover.complete
#重启mysql服务
[[email protected] ~]# service mysqld start Starting MySQL (Percona Server)... SUCCESS!
#在manager的日子文件中找到主从同步的sql语句
[[email protected] mha]# grep MASTER_HOST /usr/local/mha/manager.log Mon Feb 22 11:00:38 2016 - [info] All other slaves should start replication from here. Statement should be: CHANGE MASTER TO MASTER_HOST=‘192.168.253.242‘, MASTER_PORT=3306, MASTER_LOG_FILE=‘mysql-bin.000004‘, MASTER_LOG_POS=700, MASTER_USER=‘backup‘, MASTER_PASSWORD=‘xxx‘;
#在master上启动主从同步，密码为backup
mysql> change master to -> master_host=‘192.168.253.242‘,master_user=‘backup‘,master_password=‘backup‘,master_port=3306,master_log_file=‘mysql-bin.000004‘,master_log_pos=700; Query OK, 0 rows affected, 2 warnings (0.75 sec) mysql> start slave; Query OK, 0 rows affected (0.05 sec)
#在master和slave02上执行，检查主从同步是否都正常，这里以master为例，slave02同理
[[email protected] ~]# mysql -uroot -p123456 -e ‘show slave status\G‘ |egrep ‘Master_Host|Slave_IO_Running:|Slave_SQL_Running:‘ Warning: Using a password on the command line interface can be insecure. Master_Host: 192.168.253.242 Slave_IO_Running: Yes Slave_SQL_Running: Yes
5、再次启动MHA的manager服务，并停止slave01
[[email protected] ~]# nohup masterha_manager --conf=/usr/local/mha/mha.cnf > /tmp/mha_manager.log 2>&1 &
#关闭slave01的mysql服务
[[email protected] ~]# service mysqld stop Shutting down MySQL... SUCCESS [[email protected] mha]# tail -f /usr/local/mha/manager.log ----- Failover Report ----- mha: MySQL Master failover 192.168.253.242 to 192.168.253.241 succeeded Master 192.168.253.242 is down! Check MHA Manager logs at manager:/usr/local/mha/manager.log for details. Started automated(non-interactive) failover. The latest slave 192.168.253.241(192.168.253.241:3306) has all relay logs for recovery. Selected 192.168.253.241 as a new master. 192.168.253.241: OK: Applying all logs succeeded. 192.168.253.243: This host has the latest relay log events. Generating relay diff files from the latest slave succeeded. 192.168.253.243: OK: Applying all logs succeeded. Slave started, replicating from 192.168.253.241. 192.168.253.241: Resetting slave info succeeded. Master failover to 192.168.253.241(192.168.253.241:3306) completed successfully.
#在slave02上查看主从同步情况
[[email protected] ~]# mysql -uroot -p123456 -e ‘show slave status\G‘ |egrep ‘Master_Host|Slave_IO_Running:|Slave_SQL_Running:‘ Warning: Using a password on the command line interface can be insecure. Master_Host: 192.168.253.241 Slave_IO_Running: Yes Slave_SQL_Running: Yes
6、恢复slave01服务
#删除故障转移文件
[[email protected] mha]# rm -rf /usr/local/mha/mha.failover.complete
#重启mysql服务
[[email protected] ~]# service mysqld start Starting MySQL (Percona Server)... SUCCESS!
#在manager的日子文件中找到主从同步的sql语句
[[email protected] mha]# grep MASTER_HOST /usr/local/mha/manager.log Mon Feb 22 11:27:21 2016 - [info] All other slaves should start replication from here. Statement should be: CHANGE MASTER TO MASTER_HOST=‘192.168.253.241‘, MASTER_PORT=3306, MASTER_LOG_FILE=‘mysql-bin.000005‘, MASTER_LOG_POS=120, MASTER_USER=‘backup‘, MASTER_PASSWORD=‘xxx‘;
#在slave01上启动主从同步，密码为backup
mysql> change master to -> master_host=‘192.168.253.241‘,master_user=‘backup‘,master_password=‘backup‘,master_port=3306,master_log_file=‘mysql-bin.000005‘,master_log_pos=120; Query OK, 0 rows affected, 2 warnings (0.61 sec) mysql> start slave; Query OK, 0 rows affected (0.05 sec)
#在slave01和slave02上执行，检查主从同步是否都正常，这里以slave01为例，slave02同理。
[[email protected] ~]# mysql -uroot -p123456 -e ‘show slave status\G‘ |egrep ‘Master_Host|Slave_IO_Running:|Slave_SQL_Running:‘ Warning: Using a password on the command line interface can be insecure. Master_Host: 192.168.253.241 Slave_IO_Running: Yes Slave_SQL_Running: Yes
7、再次启动MHA的manager服务
[[email protected] ~]# nohup masterha_manager --conf=/usr/local/mha/mha.cnf > /tmp/mha_manager.log 2>&1 &
五、通过vip实现mysql的高可用
1、修改/usr/local/mha/mha.cnf
[server default] user=mha_rep password=123456 manager_workdir=/usr/local/mha manager_log=/usr/local/mha/manager.log master_ip_failover_script=/usr/local/mha/scripts/master_ip_failover #添加管理vip的脚本 ssh_user=root repl_user=backup repl_password=backup ping_interval=1 [server1] hostname=192.168.253.241 master_binlog_dir=/data/mysql/ candidate_master=1 [server2] hostname=192.168.253.242 master_binlog_dir=/data/mysql/ candidate_master=1 [server3] hostname=192.168.253.243 master_binlog_dir=/data/mysql/ no_master=1
2、修改脚本/usr/local/mha/scripts/master_ip_failover
#!/usr/bin/env perl
use strict;
use warnings FATAL => ‘all‘;
use Getopt::Long;
my (
$command, $ssh_user, $orig_master_host, $orig_master_ip,
$orig_master_port, $new_master_host, $new_master_ip, $new_master_port
);
my $vip = ‘192.168.253.240‘; #vip地址
my $key = ‘1‘;
my $ssh_start_vip = "/sbin/ifconfig eth0:$key $vip"; #绑定在指定的网卡上面
my $ssh_stop_vip = "/sbin/ifconfig eth0:$key down";
GetOptions(
‘command=s‘ => \$command,
‘ssh_user=s‘ => \$ssh_user,
‘orig_master_host=s‘ => \$orig_master_host,
‘orig_master_ip=s‘ => \$orig_master_ip,
‘orig_master_port=i‘ => \$orig_master_port,
‘new_master_host=s‘ => \$new_master_host,
‘new_master_ip=s‘ => \$new_master_ip,
‘new_master_port=i‘ => \$new_master_port,
);
exit &main();
sub main {
print "\n\nIN SCRIPT TEST====$ssh_stop_vip==$ssh_start_vip===\n\n";
if ( $command eq "stop" || $command eq "stopssh" ) {
my $exit_code = 1;
eval {
print "Disabling the VIP on old master: $orig_master_host \n";
&stop_vip();
$exit_code = 0;
};
if ([email protected]) {
warn "Got Error: [email protected]\n";
exit $exit_code;
}
exit $exit_code;
}
elsif ( $command eq "start" ) {
my $exit_code = 10;
eval {
print "Enabling the VIP - $vip on the new master - $new_master_host \n";
&start_vip();
$exit_code = 0;
};
if ([email protected]) {
warn [email protected];
exit $exit_code;
}
exit $exit_code;
}
elsif ( $command eq "status" ) {
print "Checking the Status of the script.. OK \n";
exit 0;
}
else {
&usage();
exit 1;
}
}
sub start_vip() {
`ssh $ssh_user\@$new_master_host \" $ssh_start_vip \"`;
}
# A simple system call that disable the VIP on the old_master
sub stop_vip() {
`ssh $ssh_user\@$orig_master_host \" $ssh_stop_vip \"`;
}
sub usage {
print
"Usage: master_ip_failover --command=start|stop|stopssh|status --orig_master_host=host --orig_master_ip=ip --orig_master_port=port --new_master_host=host --new_master_ip=ip --new_master_port=port\n";
}
3、模拟故障进行切换
#停止master的mysql服务
[[email protected] ~]# service mysqld stop Shutting down MySQL... SUCCESS!
#查看slave02的同步信息
[[email protected] ~]# mysql -uroot -p123456 -e ‘show slave status\G‘ |egrep ‘Master_Host|Slave_IO_Running:|Slave_SQL_Running:‘ Warning: Using a password on the command line interface can be insecure. Master_Host: 192.168.253.242 Slave_IO_Running: Yes Slave_SQL_Running: Yes
#查看slave01的IP信息
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether a2:28:26:4d:72:f6 brd ff:ff:ff:ff:ff:ff inet 192.168.253.242/24 brd 192.168.253.255 scope global eth0 #这里能看到vip已自动添加 inet 192.168.253.240/24 brd 192.168.253.255 scope global secondary eth0:1 3: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000 link/ether 56:17:7e:16:50:3c brd ff:ff:ff:ff:ff:ff
4、恢复master的mysql服务同开始恢复方法一样。
六.MHA日常维护命令
1.查看ssh登陆是否成功
masterha_check_ssh --conf=/usr/local/mha/mha.cnf
2.查看复制是否建立好
masterha_check_repl --conf=/usr/local/mha/mha.cnf
3.启动mha
nohup masterha_manager --conf=/usr/local/mha/mha.cnf > /tmp/mha_manager.log 2>&1 &
4.检查启动的状态
masterha_check_status --conf=/usr/local/mha/mha.cnf
5.停止mha
masterha_stop masterha_check_status --conf=/usr/local/mha/mha.cnf
6.failover后下次重启
#每次failover切换后会在管理目录生成文件app1.failover.complete ，下次在切换的时候会发现有这个文件导致切换不成功，需要手动清理掉。
rm -rf /usr/local/mha/mha.failover.complete
时间： 2024-07-29 05:05:53