Gtid主从复制

Gtid主从

事务

gtid主从里面涉及到事务(Transaction)。 事务(Transaction),一般是指要做的或所做的事情。在计算机术语中是指访问并可能更新数据库中各种数据项的一个程序执行单元(unit)。事务通常由高级数据库操纵语言或编程语言(如SQL,C++或Java)书写的用户程序的执行所引起,并用形如begin transaction和end transaction语句(或函数调用)来界定。事务由事务开始(begin transaction)和事务结束(end transaction)之间执行的全体操作组成。

1、事务的概念

  • 在关系数据库中,一个事务可以是一条SQL语句,一组SQL语句或整个程序。

2、事务的特性

  • 事务是恢复和并发控制的基本单位。
  • 事务应该具有4个属性:原子性、一致性、隔离性、持久性。这四个属性通常称为ACID特性。
    • 原子性(atomicity):一个事务是一个不可分割的工作单位,事务中包括的操作要么都做,要么都不做。
    • 一致性(consistency):事务必须是使数据库从一个一致性状态变到另一个一致性状态。一致性与原子性是密切相关的。
    • 隔离性(isolation):一个事务的执行不能被其他事务干扰。即一个事务内部的操作及使用的数据对并发的其他事务是隔离的,并发执行的各个事务之间不能互相干扰。
    • 持久性(durability):持久性也称永久性(permanence),指一个事务一旦提交,它对数据库中数据的改变就应该是永久性的。接下来的其他操作或故障不应该对其有任何影响。

3、事务的类型

1.手动事务

手动事务允许显式处理若干过程,这些过程包括:开始事务、控制事务边界内的每个连接和资源登记、确定事务结果(提交或中止)以及结束事务。尽管此模型提供了对事务的标准控制,但它缺少一些内置于自动事务模型的简化操作。例如,在手动事务中数据存储区之间没有自动登记和协调。此外,与自动事务不同,手动事务中事务不在对象间流动。 如果选择手动控制分布式事务,则必须管理恢复、并发、安全性和完整性。也就是说,必须应用维护与事务处理关联的 ACID 属性所需的所有编程方法。

2.自动事务

.NET 页、XML Web services方法或 .NET Framework 类一旦被标记为参与事务,它们将自动在事务范围内执行。您可以通过在页、XML Web services 方法或类中设置一个事务属性值来控制对象的事务行为。特性值反过来确定实例化对象的事务性行为。因此,根据声明特性值的不同,对象将自动参与现有事务或正在进行的事务,成为新事务的根或者根本不参与事务。声明事务属性的语法在 .NET Framework 类、.NET 页和 XML Web services 方法中稍有不同。 声明性事务特性指定对象如何参与事务,如何以编程方式被配置。尽管此声明性级别表示事务的逻辑,但它是一个已从物理事务中移除的步骤。物理事务在事务性对象访问数据库或消息队列这样的数据资源时发生。与对象关联的事务自动流向合适的资源管理器,诸如 OLE DB、开放式数据库连接 (ODBC) 或 ActiveX 数据对象 (ADO) 的关联驱动程序在对象的上下文中查找事务,并通过分布式事务处理协调器 (DTC) 在此事务中登记。整个物理事务自动发生。

MySQL基于Gtid的主从复制

1、Gtid概念

1.从 MySQL 5.6.5 开始新增了一种基于 GTID 的复制方式。通过 GTID保证了每个在主库上提交的事务在集群(这里的集群指的是所有的数据库)中有一个唯一的ID。这种方式强化了数据库的主备一致性,故障恢复以及容错能力。

2.在原来基于二进制日志的复制中,从库需要告知主库要从哪个偏移量进行增量同步,如果指定错误会造成数据的遗漏,从而造成数据的不一致。借助GTID,在发生主备切换的情况下,MySQL的其它从库可以自动在新主库上找到正确的复制位置,这大大简化了复杂复制拓扑下集群的维护,也减少了人为设置复制位置发生误操作的风险。另外,基于GTID的复制可以忽略已经执行过的事务,减少了数据发生不一致的风险。

2、什么是Gtid

1.GTID就是全局事务ID,GTID (Global Transaction ID) 是对于一个已提交事务的编号,并且是一个全局唯一的编号。

2.GTID 实际上 是由UUID+TID 组成的。其中 UUID 是一个 MySQL 实例的唯一标识。TID代表了该实例上已经提交的事务数量,并且随着事务提交量调整递增。

3.下面是一个GTID的具体形式:3E11FA47-71CA-11E1-9E33-C80AA9429562:23,冒号分割前边为uuid,后边为TID

4.GTID 集合可以包含来自多个 MySQL 实例的事务,它们之间用逗号分隔。

5.如果来自同一MySQL实例的事务序号有多个范围区间,各组范围之间用冒号分隔。可以使用show master status实时查看当前事务执行数。

3、Gitd的作用

1.Gtid采用了新的复制协议,旧协议(这里的旧协议指的是传统主从)是,首先从服务器上在一个特定的偏移量位置连接到主服务器上一个给定的二进制日志文件,然后主服务器再从给定的连接点开始发送所有的事件。

2.新协议有所不同,支持以全局统一事务ID (GTID)为基础的复制。当在主库上提交事务或者被从库应用时,可以定位和追踪每一个事务。GTID复制是全部以事务为基础,使得检查主从一致性变得非常简单。如果所有主库上提交的事务也同样提交到从库上,一致性就得到了保证。

配置Gtid主从

主从复制(一主一从)

主库配置文件
[root@slave ~]# cat /etc/my.cnf 
[mysqld]
basedir = /usr/local/mysql
datadir = /opt/data
port = 3306
socket = /tmp/mysql.sock
pid-file = /opt/data/mysqld.pid
skip-name-resolve

# replication config
server-id = 10
gtid-mode = on
enforce-gtid-consistency = on
log-bin = mysql_bin
binlog-format = row
log-slave-updates = 1
skip-slave-start = 1

从库配置文件
[root@slave ~]# cat /etc/my.cnf 
[mysqld]
basedir = /usr/local/mysql
datadir = /opt/data
port = 3306
socket = /tmp/mysql.sock
pid-file = /opt/data/mysqld.pid
skip-name-resolve

# replication config
server-id = 20
log-bin = mysql_bin
binlog-format = row
skip-slave-start = 1
gtid-mode = on
log-slave-updates = 1
enforce-gtid-consistency = on

查看Gtid配置是否成功

主库配置
mysql> show variables like ‘%gtid%‘;
+----------------------------------+-----------+
| Variable_name                    | Value     |
+----------------------------------+-----------+
| binlog_gtid_simple_recovery      | ON        |
| enforce_gtid_consistency         | ON        |
| gtid_executed_compression_period | 1000      |
| gtid_mode                        | ON        |
| gtid_next                        | AUTOMATIC |
| gtid_owned                       |           |
| gtid_purged                      |           |
| session_track_gtids              | OFF       |
+----------------------------------+-----------+
8 rows in set (0.00 sec)

从库配置
mysql>  show variables like ‘%gtid%‘;
+----------------------------------+-----------+
| Variable_name                    | Value     |
+----------------------------------+-----------+
| binlog_gtid_simple_recovery      | ON        |
| enforce_gtid_consistency         | ON        |
| gtid_executed_compression_period | 1000      |
| gtid_mode                        | ON        |
| gtid_next                        | AUTOMATIC |
| gtid_owned                       |           |
| gtid_purged                      |           |
| session_track_gtids              | OFF       |
+----------------------------------+-----------+
8 rows in set (0.00 sec)

授权
mysql> grant replication slave on *.* to ‘repl‘@‘192.168.145.171‘ identified by ‘repl123!‘;
Query OK, 0 rows affected, 1 warning (0.00 sec)

刷新
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

配置并启动主从复制
mysql> change master to
    -> master_host=‘192.168.145.169‘,
    -> master_user=‘repl‘,
    -> master_password=‘repl123!‘,
    -> master_auto_position=1;
Query OK, 0 rows affected, 2 warnings (0.00 sec)

mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.145.169
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql_bin.000002
          Read_Master_Log_Pos: 154
               Relay_Log_File: slave-relay-bin.000002
                Relay_Log_Pos: 367
        Relay_Master_Log_File: mysql_bin.000002
             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: 154
              Relay_Log_Space: 574
              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: 10
                  Master_UUID: 9b67a880-0a7a-11ec-b3fe-000c298fc665
             Master_Info_File: /opt/data/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           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: 1
         Replicate_Rewrite_DB: 
                 Channel_Name: 
           Master_TLS_Version: 
1 row in set (0.00 sec)

验证

查看主库数据
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.01 sec)

查看从库数据
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.00 sec)

主库创建数据
mysql> create database school;
Query OK, 1 row affected (0.00 sec)

从库查看数据
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| school             |
| sys                |
+--------------------+
5 rows in set (0.00 sec)

进入school创建表
mysql> use school
Database changed
mysql> create table student(di int not null primary key auto_increment,name varchar(50),age tinyint);
Query OK, 0 rows affected (0.00 sec)

mysql> desc student;
+-------+-------------+------+-----+---------+----------------+
| Field | Type        | Null | Key | Default | Extra          |
+-------+-------------+------+-----+---------+----------------+
| di    | int(11)     | NO   | PRI | NULL    | auto_increment |
| name  | varchar(50) | YES  |     | NULL    |                |
| age   | tinyint(4)  | YES  |     | NULL    |                |
+-------+-------------+------+-----+---------+----------------+
3 rows in set (0.00 sec)

从库查看school内容
mysql> show tables;
+------------------+
| Tables_in_school |
+------------------+
| student          |
+------------------+
1 row in set (0.00 sec)

主从复制(一主两从)

主库配置文件
[root@slave ~]# cat /etc/my.cnf 
[mysqld]
basedir = /usr/local/mysql
datadir = /opt/data
port = 3306
socket = /tmp/mysql.sock
pid-file = /opt/data/mysqld.pid
skip-name-resolve

# replication config
server-id = 10
gtid-mode = on
enforce-gtid-consistency = on
log-bin = mysql_bin
binlog-format = row
log-slave-updates = 1
skip-slave-start = 1

从库1配置文件
[root@slave ~]# cat /etc/my.cnf 
[mysqld]
basedir = /usr/local/mysql
datadir = /opt/data
port = 3306
socket = /tmp/mysql.sock
pid-file = /opt/data/mysqld.pid
skip-name-resolve

# replication config
server-id = 20
log-bin = mysql_bin
binlog-format = row
skip-slave-start = 1
gtid-mode = on
log-slave-updates = 1
enforce-gtid-consistency = on

从库2配置文件
[root@slave1 ~]# cat /etc/my.cnf 
[mysqld]
basedir = /usr/local/mysql
datadir = /opt/data
port = 3306
socket = /tmp/mysql.sock
pid-file = /opt/data/mysqld.pid
skip-name-resolve

# replication config
server-id = 21
log-bin = mysql_bin
binlog-format = row
skip-slave-start = 1
gtid-mode = on
log-slave-updates = 1
enforce-gtid-consistency = on

查看Gtid配置是否成功

主库配置
mysql> show variables like ‘%gtid%‘;
+----------------------------------+-----------+
| Variable_name                    | Value     |
+----------------------------------+-----------+
| binlog_gtid_simple_recovery      | ON        |
| enforce_gtid_consistency         | ON        |
| gtid_executed_compression_period | 1000      |
| gtid_mode                        | ON        |
| gtid_next                        | AUTOMATIC |
| gtid_owned                       |           |
| gtid_purged                      |           |
| session_track_gtids              | OFF       |
+----------------------------------+-----------+
8 rows in set (0.00 sec)

从库1配置
mysql>  show variables like ‘%gtid%‘;
+----------------------------------+-----------+
| Variable_name                    | Value     |
+----------------------------------+-----------+
| binlog_gtid_simple_recovery      | ON        |
| enforce_gtid_consistency         | ON        |
| gtid_executed_compression_period | 1000      |
| gtid_mode                        | ON        |
| gtid_next                        | AUTOMATIC |
| gtid_owned                       |           |
| gtid_purged                      |           |
| session_track_gtids              | OFF       |
+----------------------------------+-----------+
8 rows in set (0.00 sec)

从库2配置
mysql> show variables like ‘%gtid%‘;
+----------------------------------+-----------+
| Variable_name                    | Value     |
+----------------------------------+-----------+
| binlog_gtid_simple_recovery      | ON        |
| enforce_gtid_consistency         | ON        |
| gtid_executed_compression_period | 1000      |
| gtid_mode                        | ON        |
| gtid_next                        | AUTOMATIC |
| gtid_owned                       |           |
| gtid_purged                      |           |
| session_track_gtids              | OFF       |
+----------------------------------+-----------+
8 rows in set (0.00 sec)

配置并启动主从复制
mysql> change master to
    -> master_host=‘192.168.145.169‘,
    -> master_user=‘repl‘,
    -> master_password=‘repl123!‘,
    -> master_auto_position=1;
Query OK, 0 rows affected, 2 warnings (0.00 sec)

启动slave
mysql> start slave;
Query OK, 0 rows affected (0.01 sec)

mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.145.169
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql_bin.000002
          Read_Master_Log_Pos: 1297
               Relay_Log_File: slave1-relay-bin.000002
                Relay_Log_Pos: 1510
        Relay_Master_Log_File: mysql_bin.000002
             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: 1297
              Relay_Log_Space: 1718
              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: 10
                  Master_UUID: 9b67a880-0a7a-11ec-b3fe-000c298fc665
             Master_Info_File: /opt/data/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           Master_Retry_Count: 86400
                  Master_Bind: 
      Last_IO_Error_Timestamp: 
     Last_SQL_Error_Timestamp: 
               Master_SSL_Crl: 
           Master_SSL_Crlpath: 
           Retrieved_Gtid_Set: 9b67a880-0a7a-11ec-b3fe-000c298fc665:1-5
            Executed_Gtid_Set: 9b67a880-0a7a-11ec-b3fe-000c298fc665:1-5
                Auto_Position: 1
         Replicate_Rewrite_DB: 
                 Channel_Name: 
           Master_TLS_Version: 
1 row in set (0.00 sec)

验证

查看主库数据
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.01 sec)

查看从库1数据
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.00 sec)

主库创建数据
mysql> create database school;
Query OK, 1 row affected (0.00 sec)

从库1查看数据
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| school             |
| sys                |
+--------------------+
5 rows in set (0.00 sec)

进入school创建表
mysql> use school
Database changed
mysql> create table student(di int not null primary key auto_increment,name varchar(50),age tinyint);
Query OK, 0 rows affected (0.00 sec)

mysql> desc student;
+-------+-------------+------+-----+---------+----------------+
| Field | Type        | Null | Key | Default | Extra          |
+-------+-------------+------+-----+---------+----------------+
| di    | int(11)     | NO   | PRI | NULL    | auto_increment |
| name  | varchar(50) | YES  |     | NULL    |                |
| age   | tinyint(4)  | YES  |     | NULL    |                |
+-------+-------------+------+-----+---------+----------------+
3 rows in set (0.00 sec)

从库1查看school内容
mysql> show tables;
+------------------+
| Tables_in_school |
+------------------+
| student          |
+------------------+
1 row in set (0.00 sec)

查看从库2数据
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.00 sec)

从库2查看school内容
mysql> show tables;
+------------------+
| Tables_in_school |
+------------------+
| student          |
+------------------+
1 row in set (0.00 sec)

主从复制(两主一从)

配置并启动主从复制
mysql> change master to
    -> master_host=‘192.168.145.169‘,
    -> master_user=‘repl‘,
    -> master_password=‘repl123!‘,
    -> master_auto_position=1;
Query OK, 0 rows affected, 2 warnings (0.00 sec)

mysql> change master to 
    -> master_host=‘192.168.145.170‘,
    -> master_user=‘repl‘,
    -> master_password=‘repl123!‘,
    -> master_auto_position=1;
Query OK, 0 rows affected, 2 warnings (0.01 sec)

mysql> start slave;
Query OK, 0 rows affected (0.00 sec)

mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.145.169
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql_bin.000002
          Read_Master_Log_Pos: 1297
               Relay_Log_File: slave1-relay-bin.000002
                Relay_Log_Pos: 1510
        Relay_Master_Log_File: mysql_bin.000002
             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: 1297
              Relay_Log_Space: 1718
              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: 10
                  Master_UUID: 9b67a880-0a7a-11ec-b3fe-000c298fc665
             Master_Info_File: /opt/data/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           Master_Retry_Count: 86400
                  Master_Bind: 
      Last_IO_Error_Timestamp: 
     Last_SQL_Error_Timestamp: 
               Master_SSL_Crl: 
           Master_SSL_Crlpath: 
           Retrieved_Gtid_Set: 9b67a880-0a7a-11ec-b3fe-000c298fc665:1-5
            Executed_Gtid_Set: 9b67a880-0a7a-11ec-b3fe-000c298fc665:1-5
                Auto_Position: 1
         Replicate_Rewrite_DB: 
                 Channel_Name: 
           Master_TLS_Version: 
1 row in set (0.00 sec)

从库连接主库1
[root@slave1 ~]# mysql -urepl -prepl123! -h192.168.145.169
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 10
Server version: 5.7.34-log MySQL Community Server (GPL)

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.

从库连接主库2
[root@slave1 ~]# mysql -urepl -prepl123! -h192.168.145.70
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 10
Server version: 5.7.34-log MySQL Community Server (GPL)

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.

Gtid主从复制

上一篇:迭代器模式


下一篇:敏捷估算