MySQL5.6:基于GTID的主从复制

时间:2023-03-08 16:52:38

一、GTID简介

MySQL 5.6 的新特性之一,是加入了全局事务 ID (GTID) 来强化数据库的主备一致性,故障恢复,以及容错能力。

什么是GTID?

官方文档:http://dev.mysql.com/doc/refman/5.6/en/replication-gtids.html在这篇文档里,我们可以知道全局事务 ID 的官方定义是:GTID = source_id:transaction_id

MySQL 5.6 中,每一个 GTID 代表一个数据库事务。在上面的定义中,source_id 表示执行事务的主库 uuid(server_uuid),transaction_id 是一个从 1 开始的自增计数,表示在这个主库上执行的第 n 个事务。MySQL 会保证事务与 GTID 之间的 1 : 1 映射。

二、环境准备

操作系统:CentOS6.5 64位

数据库版本:MySQL5.6.23

MySQL5.6:基于GTID的主从复制

拓扑如下:

MySQL5.6:基于GTID的主从复制

三、安装主数据库(masterdb.example.com)

1、准备数据存放目录、创建用户

  [root@masterdb ~]#mkdir /data/mysqldata -p   #创建数据存放目录
[root@masterdb ~]#mkdir /data/mysqlLog/logs -p #创建日志存放目录
[root@masterdb ~]#groupadd -r mysql
[root@masterdb ~]#useradd -g mysql -r -s /sbin/nologin -M -d /data/mysqldata mysql
[root@masterdb ~]#chown -R mysql:mysql /data/mysqldata
[root@masterdb ~]#chown -R mysql:mysql /data/mysqlLog/logs

2、安装并初始化mysql5.6.23

 [root@masterdb ~]# tar xf mysql-advanced-5.6.-linux-glibc2.-x86_64.tar.gz -C /usr/local/
[root@masterdb ~]# cd /usr/local/
[root@masterdb ~]# ln -sv mysql-advanced-5.6.-linux-glibc2.-x86_64 mysql
[root@masterdb ~]# chown -R root.mysql mysql
[root@masterdb ~]# cd mysql
[root@masterdb ~]# cp support-files/mysql.server /etc/rc.d/init.d/mysqld
[root@masterdb ~]# cp support-files/my-default.cnf /etc/my.cnf
[root@masterdb ~]# chmod +x /etc/rc.d/init.d/mysqld
[root@masterdb ~]# chkconfig --add mysqld
[root@masterdb ~]# chkconfig mysqld on
[root@masterdb ~]# ./scripts/mysql_install_db --user=mysql --datadir=/data/mysqldata/

3、输出mysql的man手册至man命令的查找路径:

编辑/etc/man.config,添加如下行即可:
MANPATH  /usr/local/mysql/man

4、输出mysql的头文件至系统头文件路径/usr/include:

这可以通过简单的创建链接实现:

 [root@masterdb ~]#ln -sv /usr/local/mysql/include  /usr/include/mysql

5、输出mysql的库文件给系统库查找路径:

 [root@masterdb ~]#echo '/usr/local/mysql/lib' > /etc/ld.so.conf.d/mysql.conf

而后让系统重新载入系统库:

 [root@masterdb ~]# ldconfig

6、修改PATH环境变量,让系统可以直接使用mysql的相关命令:

 [root@masterdb ~]# vim /etc/profile.d/mysql.sh
export PATH=$PATH:/usr/local/mysql/bin
[root@masterdb ~]#source /etc/profile.d/mysql.sh

从数据库安装同上,具体过程略过。

四、分别为主从数据库提供配置文件/etc/my.cnf

要在MySQL 5.6中使用复制功能,其服务配置段[mysqld]中于少应该定义如下选项:
binlog-format:二进制日志的格式,有row、statement和mixed几种类型;
    需要注意的是:当设置隔离级别为READ-COMMITED必须设置二进制日志格式为ROW,现在MySQL官方认为STATEMENT这个已经不再适合继续使用;但mixed类型在默认的事务隔离级别下,可能会导致主从数据不一致;
log-slave-updates、gtid-mode、enforce-gtid-consistency、report-port和report-host:用于启动GTID及满足附属的其它需求;
master-info-repository和relay-log-info-repository:启用此两项,可用于实现在崩溃时保证二进制及从服务器安全的功能;
sync-master-info:启用之可确保无信息丢失;
slave-paralles-workers:设定从服务器的SQL线程数;0表示关闭多线程复制功能;
binlog-checksum、master-verify-checksum和slave-sql-verify-checksum:启用复制有关的所有校验功能;
binlog-rows-query-log-events:启用之可用于在二进制日志记录事件相关的信息,可降低故障排除的复杂度;
log-bin:启用二进制日志,这是保证复制功能的基本前提;
server-id:同一个复制拓扑中的所有服务器的id号必须惟一;

主数据库上:

 [client]
port =
socket = /tmp/mysql.sock
default-character-set = utf8
[mysql]
no-auto-rehash
default-character-set = utf8 [mysqld]
server-id =
port =
user = mysql
basedir = /usr/local/mysql
datadir = /data/mysqldata
socket = /tmp/mysql.sock
default-storage-engine = INNODB
character-set-server = utf8
connect_timeout =
interactive_timeout =
wait_timeout =
back_log =
event_scheduler = ON
skip_name_resolve = ON; ###########binlog##########
log-bin = /data/mysqlLog/logs/mysql-bin
binlog_format = row
max_binlog_size = 128M
binlog_cache_size = 2M
expire-logs-days =
log-slave-updates=true
gtid-mode=on
enforce-gtid-consistency=true
master-info-repository=TABLE
relay-log-info-repository=TABLE
sync-master-info=
slave-parallel-workers=
#rpl_semi_sync_master_enabled = slow_query_log =
slow_query_log_file = /data/mysqlLog/logs/mysql.slow
long_query_time = log_error = /data/mysqlLog/logs/error.log
max_connections =
max_connect_errors =
log_bin_trust_function_creators =
transaction_isolation = READ-COMMITTED

从数据库上:

 [client]
port =
socket = /tmp/mysql.sock
default-character-set = utf8 [mysql]
no-auto-rehash
default-character-set = utf8 [mysqld]
server-id =
port =
user = mysql
basedir = /usr/local/mysql
datadir = /data/mysqldata
socket = /tmp/mysql.sock
default-storage-engine = INNODB
character-set-server = utf8
connect_timeout =
wait_timeout =
back_log =
event_scheduler = ON ###########binlog##########
log-bin = /data/mysqlLog/logs/mysql-bin
binlog_format = row
max_binlog_size = 128M
binlog_cache_size = 2M
expire-logs-days =
log-slave-updates=true
gtid-mode=on
enforce-gtid-consistency=true
master-info-repository=TABLE
relay-log-info-repository=TABLE
sync-master-info=
slave-parallel-workers=
#rpl_semi_sync_slave_enabled =
skip-slave-start slow_query_log =
slow_query_log_file = /data/mysqlLog/logs/mysql.slow
long_query_time = log-error = /data/mysqlLog/logs/error.log
max_connections =
max_connect_errors =
log_bin_trust_function_creators =
transaction_isolation = READ-COMMITTED

五、分别在主从数据库上启动mysqld服务

 [root@masterdb ~]# service mysqld start
Starting MySQL...... [ OK ]
[root@masterdb ~]#
 [root@slavedb ~]# service mysqld start
Starting MySQL...... [ OK ]
[root@slavedb ~]#

六、在主数据库上创建复制用户

 mysql> GRANT REPLICATION SLAVE ON *.* TO repluser@172.16.88.205 IDENTIFIED BY 'replpassword';

说明:172.16.88.205是从节点服务器;如果想一次性授权更多的节点,可以自行根据需要修改;

七、启动从数据库上的复制线程

mysql> CHANGE MASTER TO MASTER_HOST='masterdb.example.com', MASTER_USER='repluser', MASTER_PASSWORD='replpassword', MASTER_AUTO_POSITION=;
mysql>start slave;

八、在从数据库上查看复制状态:

mysql> show slave status\G;
*************************** . row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: masterdb.56xyl.com
Master_User: repluser
Master_Port:
Connect_Retry:
Master_Log_File: mysql-bin.
Read_Master_Log_Pos:
Relay_Log_File: slavedb-relay-bin.
Relay_Log_Pos:
Relay_Master_Log_File: mysql-bin.
Slave_IO_Running: Yes #IO线程已正常运行
Slave_SQL_Running: Yes #SQL线程已正常运行
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno:
Last_Error:
Skip_Counter:
Exec_Master_Log_Pos:
Relay_Log_Space:
Until_Condition: None
Until_Log_File:
Until_Log_Pos:
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master:
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno:
Last_IO_Error:
Last_SQL_Errno:
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id:
Master_UUID: 971d7245-c3f8-11e5-8b6b-000c2999e5a5
Master_Info_File: mysql.slave_master_info
SQL_Delay:
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:
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set: 971d7245-c3f8-11e5-8b6b-000c2999e5a5:-
Executed_Gtid_Set: 89e78301-c3f4-11e5-8b51-00505624d26a:-,
971d7245-c3f8-11e5-8b6b-000c2999e5a5:-
Auto_Position:
row in set (0.00 sec) ERROR:
No query specified mysql>

九、测试

在主库上创建数据库:

 mysql> create database log_statics;
Query OK, row affected (0.11 sec) mysql> use log_statics;
Database changed

到从数据库上查看log_statics是否已经复制过去

 mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| log_statics |
| mysql |
| performance_schema |
+--------------------+
rows in set (0.01 sec) mysql>

可以看到log_statics数据库已经存在于从数据库上。