标签：details root interval term show conf mysql cat ilo
192.168.205.37: as MHA server
192.168.205.47: as Master server
192.168.205.57: as Slave1 server
192.168.205.67: as Slave2 server
OS: centos 7 1810 with mini install
mariadb-server 5.5.60
mha4mysql-manager-0.56-0.el6.noarch.rpm
mha4mysql-node-0.56-0.el6.noarch.rpm
MHA使用perl脚本写的程序，当主节点down时如果从节点复制没有完成时，当他成为主节点后，它需要尝试将主节点的二进制日志复制到新的主节点，从而保证数据的完整性，所以它需要sshkey验证。我们使用一台做为管理节点，其中三个为数据库节点，一主两从，模拟主节点down机，看从是如何被提升为主节点的。
[root@master data]#cat maridb_yum.sh
#!/bin/bash
ID=`ip a show dev eth0 | sed -r ‘3!d;s@(.*inet)(.*)(/.*)@\2@‘ | cut -d. -f4`
rpm -q mariadb-server ||yum install -y mariadb-server
[ -d /data/mysql ] || mkdir -p /data/mysql
[ -d /data/logs ] || mkdir -p /data/logs
chown mysql:mysql /data/{mysql,logs}
sed -i ‘s@datadir=/var/lib/mysql@datadir=/data/mysql@‘ /etc/my.cnf
grep "log-bin" /etc/my.cnf || sed -i ‘/\[mysqld\]/a log-bin=/data/logs/bin‘ /etc/my.cnf
grep "innodb_file_per_table" /etc/my.cnf || sed -i ‘/\[mysqld\]/a innodb_file_per_table = on‘ /etc/my.cnf
grep "skip_name_resolve" /etc/my.cnf || sed -i ‘/\[mysqld\]/a skip_name_resolve = on‘ /etc/my.cnf
grep "server-id" /etc/my.cnf || sed -i "/\[mysqld\]/a server-id=$ID" /etc/my.cnf
service mariadb restart[root@slave1 data]#vi /etc/my.cnf
[mysqld]
read_only
relay_log_purge=0 #不删除中继日志建立主节点的复制位置和帐号
MariaDB [(none)]> show master logs;
+------------+-----------+
| Log_name | File_size |
+------------+-----------+
| bin.000001 | 30373 |
| bin.000002 | 1038814 |
| bin.000003 | 245 |
+------------+-----------+
3 rows in set (0.00 sec)
MariaDB [(none)]> grant replication slave on *.* to repluser@‘192.168.205.%‘ identified by ‘centos‘;
Query OK, 0 rows affected (0.00 sec)
MariaDB [(none)]> grant all on *.* to mhauser@‘192.168.205.%‘ identified by ‘centos‘;
Query OK, 0 rows affected (0.00 sec)配置从节点的change master to并启动线程
MariaDB [(none)]> CHANGE MASTER TO
-> MASTER_HOST=‘192.168.205.47‘,
-> MASTER_USER=‘repluser‘,
-> MASTER_PASSWORD=‘centos‘,
-> MASTER_PORT=3306,
-> MASTER_LOG_FILE=‘bin.000003‘,
-> MASTER_LOG_POS=245;
Query OK, 0 rows affected (0.01 sec)
MariaDB [(none)]> start slave;
Query OK, 0 rows affected (0.00 sec)
MariaDB [(none)]> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.205.47
Master_User: repluser
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: bin.000003
Read_Master_Log_Pos: 401
Relay_Log_File: mariadb-relay-bin.000002
Relay_Log_Pos: 679
Relay_Master_Log_File: bin.000003
Slave_IO_Running: Yes
Slave_SQL_Running: Yes[root@MHA ~]#yum install mha4mysql-manager-0.56-0.el6.noarch.rpm mha4mysql-node-0.56-0.el6.noarch.rpm [root@master ~]#yum install mha4mysql-node-0.56-0.el6.noarch.rpm
[root@slave1 data]#yum install mha4mysql-node-0.56-0.el6.noarch.rpm
[root@slave2 data]#yum install mha4mysql-node-0.56-0.el6.noarch.rpm [root@MHA ~]#ssh-keygen
[root@MHA ~]#ssh-copy-id 192.168.205.37
[root@MHA ~]#cat .ssh/authorized_keys
[root@MHA ~]#scp -r .ssh 192.168.205.47:/root/
[root@MHA ~]#scp -r .ssh 192.168.205.57:/root/
[root@MHA ~]#scp -r .ssh 192.168.205.67:/root/[root@MHA ~]#mkdir /etc/mha
[root@MHA ~]#vim /etc/mha/app1.cnf
[server default]
master_binlog_dir=/data/logs/
user=mhauser
password=centos
manager_workdir=/data/mastermha/app1/
manager_log=/data/mastermha/app1/manager.log
remote_workdir=/data/mastermha/app1/
ssh_user=root
repl_user=repluser
repl_password=centos
ping_interval=1
[server1]
hostname=192.168.205.47
candidate_master=1
[server2]
hostname=192.168.205.57
[server3]
hostname=192.168.205.67
candidate_master=1[root@MHA ~]#masterha_check_ssh --conf=/etc/mha/app1.cnf
[root@MHA ~]#masterha_check_repl --conf=/etc/mha/app1.cnf[root@MHA ~]#masterha_manager --conf=/etc/mha/app1.cnf
Mon Aug 12 23:33:22 2019 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.
Mon Aug 12 23:33:22 2019 - [info] Reading application default configuration from /etc/mha/app1.cnf..
Mon Aug 12 23:33:22 2019 - [info] Reading server configuration from /etc/mha/app1.cnf..我们模拟一个正在写入操作时，主节点down, 看服务器能不能正常切换并不能复制丢失的数据
MariaDB [(none)]> use test;
Database changed
MariaDB [test]> create table testlog (id int auto_increment primary key,name char(10),age int default 20);
Query OK, 0 rows affected (0.01 sec)
MariaDB [test]>
MariaDB [test]> delimiter $$
MariaDB [test]>
MariaDB [test]> create procedure sp_testlog()
-> begin
-> declare i int;
-> set i = 1;
-> while i <= 100000
-> do insert into testlog(name,age) values (concat(‘wang‘,i),i);
-> set i = i +1;
-> end while;
-> end$$
Query OK, 0 rows affected (0.00 sec)
MariaDB [test]>
MariaDB [test]> delimiter ;
MariaDB [test]> call sp_testlog;[root@MHA ~]#masterha_manager --conf=/etc/mha/app1.cnf
Mon Aug 12 23:33:22 2019 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.
Mon Aug 12 23:33:22 2019 - [info] Reading application default configuration from /etc/mha/app1.cnf..
Mon Aug 12 23:33:22 2019 - [info] Reading server configuration from /etc/mha/app1.cnf..
Mon Aug 12 23:45:16 2019 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.
Mon Aug 12 23:45:16 2019 - [info] Reading application default configuration from /etc/mha/app1.cnf..
Mon Aug 12 23:45:16 2019 - [info] Reading server configuration from /etc/mha/app1.cnf..
[root@MHA ~]#我们可以查看日志看一下发生的情况，slave2提升为主
[root@MHA data]#cat mastermha/app1/manager.log
----- Failover Report -----
app1: MySQL Master failover 192.168.205.47(192.168.205.47:3306) to 192.168.205.67(192.168.205.67:3306) succeeded
Master 192.168.205.47(192.168.205.47:3306) is down!
Check MHA Manager logs at MHA:/data/mastermha/app1/manager.log for details.
Started automated(non-interactive) failover.
The latest slave 192.168.205.57(192.168.205.57:3306) has all relay logs for recovery.
Selected 192.168.205.67(192.168.205.67:3306) as a new master.
192.168.205.67(192.168.205.67:3306): OK: Applying all logs succeeded.
192.168.205.57(192.168.205.57:3306): This host has the latest relay log events.
Generating relay diff files from the latest slave succeeded.
192.168.205.57(192.168.205.57:3306): OK: Applying all logs succeeded. Slave started, replicating from 192.168.205.67(192.168.205.67:3306)
192.168.205.67(192.168.205.67:3306): Resetting slave info succeeded.
Master failover to 192.168.205.67(192.168.205.67:3306) completed successfully.MariaDB [(none)]> show slave status\G
Empty set (0.00 sec)MariaDB [test]> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.205.67
Master_User: repluser
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: bin.000005
Read_Master_Log_Pos: 245
Relay_Log_File: mariadb-relay-bin.000002
Relay_Log_Pos: 523
Relay_Master_Log_File: bin.000005
Slave_IO_Running: Yes
Slave_SQL_Running: YesMariaDB [(none)]> show variables like ‘read_only‘;
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| read_only | OFF |
+---------------+-------+
1 row in set (0.00 sec)标签：details root interval term show conf mysql cat ilo
原文地址：https://blog.51cto.com/127601/2428895
