mysql slave_sql_running 多线程

实现"mysql slave_sql_running 多线程"的过程及代码示例

1. 流程图示

erDiagram
    MySQL -->|主线程| Slave SQL
    MySQL -->|主线程| Slave IO
    Slave SQL -->|子线程| 处理SQL语句
    Slave IO -->|子线程| 读取binlog

2. 步骤及代码示例

步骤1：启用多线程复制

在MySQL配置文件（如my.cnf）中，找到并修改以下两个参数：

[mysqld]
...
slave_parallel_workers=4  # 设置并行复制的线程数，此处设置为4
slave_preserve_commit_order=1  # 保持主从复制的事务顺序
...

步骤2：启动主从复制

# 从服务器连接到主服务器
CHANGE MASTER TO
MASTER_HOST='master_host',
MASTER_USER='replication_user',
MASTER_PASSWORD='replication_password',
MASTER_PORT=master_port,
MASTER_LOG_FILE='log_file',
MASTER_LOG_POS=log_position;

# 启动从服务器复制
START SLAVE;

步骤3：检查复制状态

SHOW SLAVE STATUS\G

检查结果中的"Slave_IO_Running"和"Slave_SQL_Running"状态是否为"Yes"。如果为"Yes"，则表示主从复制已正常运行。

步骤4：查看多线程复制状态

SHOW GLOBAL VARIABLES LIKE 'slave_parallel_workers';

检查结果中的"Value"是否与步骤1中配置的"slave_parallel_workers"参数相同。如果相同，则表示多线程复制已启用成功。

3. 类图示例

classDiagram
    class MySQL {
        -host: string
        -port: int
        -user: string
        -password: string
        +connect(): void
        +executeQuery(query: string): ResultSet
    }

4. 完整代码示例

import java.sql.*;
 
public class MySQL {
    private String host;
    private int port;
    private String user;
    private String password;
    private Connection connection;
 
    public MySQL(String host, int port, String user, String password) {
        this.host = host;
        this.port = port;
        this.user = user;
        this.password = password;
    }
 
    public void connect() {
        String url = "jdbc:mysql://" + host + ":" + port + "/";
        try {
            connection = DriverManager.getConnection(url, user, password);
            System.out.println("Connected to MySQL server");
        } catch (SQLException e) {
            System.out.println("Failed to connect to MySQL server");
            e.printStackTrace();
        }
    }
 
    public ResultSet executeQuery(String query) {
        try {
            Statement statement = connection.createStatement();
            return statement.executeQuery(query);
        } catch (SQLException e) {
            System.out.println("Failed to execute query");
            e.printStackTrace();
        }
        return null;
    }
 
    public static void main(String[] args) {
        MySQL mysql = new MySQL("localhost", 3306, "root", "password");
        mysql.connect();
 
        // 执行SQL查询
        ResultSet resultSet = mysql.executeQuery("SELECT * FROM users");
        try {
            while (resultSet.next()) {
                String username = resultSet.getString("username");
                String email = resultSet.getString("email");
                System.out.println("Username: " + username + ", Email: " + email);
            }
        } catch (SQLException e) {
            System.out.println("Failed to iterate result set");
            e.printStackTrace();
        }
    }
}

以上是实现"mysql slave_sql_running 多线程"的步骤及代码示例。通过配置参数和启动主从复制，可以开启多线程复制功能，提高MySQL数据复制的性能和效率。