Written by
arstercz
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mha 部署及流程说明
mha (Mysql Master High Availability Manaager) 流程及部署说明
一. 系统环境 ** 管理节点
Hostname | mgr.com
Platform | Linux
Release | CentOS release 6.4 (Final)
Kernel | 2.6.32-358.el6.i686
Architecture | CPU = 32-bit, OS = 32-bit
** 节点1
Hostname | node1.com
System | innotek GmbH; VirtualBox; v1.2 (Other)
Service Tag | 0
Platform | Linux
Release | CentOS release 5.5 (Final)
Kernel | 2.6.18-194.el5
Architecture | CPU = 32-bit, OS = 32-bit
** 节点2
Hostname | node2.com
System | innotek GmbH; VirtualBox; v1.2 (Other)
Service Tag | 0
Platform | Linux
Release | CentOS release 5.5 (Final)
Kernel | 2.6.18-194.el5
Architecture | CPU = 32-bit, OS = 32-bit
** 节点3
Hostname | node3.com
Platform | Linux
Release | CentOS release 6.4 (Final)
Kernel | 2.6.32-358.el6.i686
Architecture | CPU = 32-bit, OS = 32-bit
二. 实验环境:
192.168.56.108 (current master)
+--192.168.56.109
+--192.168.56.110
vip - 192.168.56.200
From:
192.168.56.108 (current master)
+--192.168.56.109
+--192.168.56.110
To:
192.168.56.109 (new master)
+--192.168.56.110
详细参数:
node1.com 192.168.56.108
Version 5.5.30-rel30.2-log
Server ID 199914
Uptime 3+15:39:49 (started 2013-05-30T19:12:20)
Replication Is not a slave, has 2 slaves connected, is not read_only
Filters binlog_ignore_db=mysql,test,information_schema,performance_schema
Binary logging STATEMENT
Slave status
Slave mode STRICT
Auto-increment increment 1, offset 1
InnoDB version 5.5.30-rel30.2
+- 192.168.56.109
Version 5.5.30-rel30.2-log
Server ID 134378
Uptime 3+15:20:38 (started 2013-05-30T19:31:31)
Replication Is a slave, has 0 slaves connected, is read_only
Filters binlog_ignore_db=mysql,test,information_schema,performance_schema; replicate_ignore_db=mysql,test,information_schema,performance_schema
Binary logging STATEMENT
Slave status 0 seconds behind, running, no errors
Slave mode STRICT
Auto-increment increment 1, offset 1
InnoDB version 5.5.30-rel30.2
+- 192.168.56.110
Version 5.5.30-rel30.2-log
Server ID 68842
Uptime 3+15:43:24 (started 2013-05-30T19:08:46)
Replication Is a slave, has 0 slaves connected, is not read_only
Filters binlog_ignore_db=mysql,test,information_schema,performance_schema; replicate_ignore_db=mysql,test,information_schema,performance_schema
Binary logging STATEMENT
Slave status 0 seconds behind, running, no errors
Slave mode STRICT
Auto-increment increment 1, offset 1
InnoDB version 5.5.30-rel30.2
三. 配置说明 详细参数见 : Parameters
全局配置:
[root@mgr tmha]# cat global.conf
[server default]
user=root
repl_user=replica
port=3306
init_conf_load_script=/usr/local/bin/init_conf_loads # 密码信息，不以明文方式显示,init_conf_loads脚本通过base64封装密码;
ssh_user=root
master_binlog_dir=/web/mysql/node3306/data ## mysql server 数据目录,主从目录需一致,否则每次切换主从后，改参数都需更新.
remote_workdir=/web/log/masterha ## mha 管理节点处理的日志信息
ping_interval=3
master_ip_failover_script=/usr/local/bin/master_ip_failover ## 不定义stop函数 (见流程说明), 定义start函数 切换vip地址
#shutdown_script=/usr/local/bin/power_manager
report_script=/usr/local/bin/send_report ## mail 命令发送报告
应用配置 (主从对)
[root@mgr tmha]# cat tcase.cnf
[server default]
manager_workdir=/web/log/mha/tcase1
manager_log=/web/log/mha/tcase1/case1.log
[server1]
hostname=192.168.56.108
candidate_master=1 # master 候选
[server2]
hostname=192.168.56.109
candidate_master=1 # master 候选
[server3]
hostname=192.168.56.110
no_master=1 # 永远不做master.
mha启用
nohup masterha_manager --global_conf=/web/tmha/global.conf --conf=/web/tmha/tcase.cnf --ignore_last_failover > /web/tmha/manager.log 2>&1 &
四. 流程说明
Sequences_of_MHA
| 复制设置和当前 master 的检测 | 注 1
|
|
| 验证 | -- N -> exit.
|
Y
|
| 监控master | -- no die --> wait until master dies. 注 2
| /
die /
| /
| master 连续3次失败 | -- N --+ 注 3
|
Y
|
| 检测 slave 配置 | -- N --> stop with error. 注 4
|
Y
|
| last failover | [optional] -- Y --> stop ||--> ignore this setup by using ignore_last_failover
|
N
|
| master_ip_failover | [optional] -- Y -- stop server || -> 注1 modify script based on environment. 注 5
|
N
|
| recovering new master | -- 1. saving binaty log [optinal] -- 2. determining new master -- 3. latest slave -- 4. recovering and promoting new master. 注 6.
|
| activating new master | -- switch virtual ip address [optional] 注 7.
|
| recovering rest slaves |
|
| notification | [optional] --- sending mails
注 :
MHA::ServerManager::validate_slaves() slave检测; MHA::ServerManager::get_current_alive_master() 当前master;
2.
apply_diff_relay_logs --command=test --slave_user='root' --slave_host=192.168.56.110 --slave_ip=192.168.56.110 --slave_port=3306
MHA::SSHCheck::do_ssh_connection_check() -- ssh 检测; MHA::MasterMonitor::check_slave_env() slave环境检测; MHA::ManagerUtil::exec_ssh_cmd() slave有效性检测;
MHA::HealthCheck::wait_until_unreachable() -- master 健康检查;
3.
MHA::HealthCheck::wait_until_unreachable() MHA::SSHCheck::do_ssh_connection_check() ssh 检测;
4.
MHA::MasterMonitor::wait_until_master_is_dead() master失效后的操作；
5.
MHA::MasterFailover::do_master_failover() 主故障切换;
force_shutdown -- sshrecheable : stopssh ; sshunreachable : stop mysql server
/usr/local/bin/master_ip_failover --orig_master_host=192.168.56.108 --orig_master_ip=192.168.56.108 --orig_master_port=3306 --command=stop
6.
MHA::MasterFailover::check_set_latest_slaves() ; 选择具有最新relay logs的slave;
MHA::MasterFailover::save_master_binlog() ; 获取旧master的log信息,依赖于sshreachable，如果unreachable,返回warning信息;
MHA::MasterFailover::select_new_master() ; 选择新master;
MHA::MasterFailover::recover_master_internal(); Master Log Apply;
MHA::MasterFailover::recover_master(); 启用新master, $new_master->disable_read_only() 新master禁止read_only
MHA::ServerManager::get_new_master_binlog_position() 得到新master的位置信息;
MHA::MasterFailover::recover_slave(); 更新所有slave 记录,与新master保持一致;
MHA::Server::reset_slave_on_new_master() , reset_slave_info and reset_slave_all 更新所有slave到新master.
/
/
MHA::DBHelper::reset_slave_by_change_master 清楚change master信息, change_master() 更新新的change master语句;
7.
/usr/local/bin/master_ip_failover --command=start --ssh_user=root --orig_master_host=192.168.56.108
--orig_master_ip=192.168.56.108 --orig_master_port=3306
--new_master_host=192.168.56.109 --new_master_ip=192.168.56.109
--new_master_port=3306 --new_master_user='root' --new_master_password='xxxxxx'