两个mysql数据同步

使用同步canal两个mysql数据使用同步canal两个mysql数据使用同步canal两个mysql数据在日常项目开发时候，经常遇到两个mysql库中表数据需要同步的情况，基以此推荐使用canal来实现自动更新。他就想象个工具连同的水管工具可以并且在同步的时候可以做自己的一些更改十分方便好用。以下是使用方法：1 canal的原理是基于mysql binlog技术，所以这里一定需要开启mys

孙红彬

2220人浏览 · 2021-06-05 09:42:41

孙红彬 · 2021-06-05 09:42:41 发布

使用同步canal两个mysql数据

使用同步canal两个mysql数据

使用同步canal两个mysql数据

在日常项目开发时候，经常遇到两个mysql库中表数据需要同步的情况，基以此推荐使用canal来实现自动更新。他就想象个工具连同的水管工具可以并且在同步的时候可以做自己的一些更改十分方便好用。以下是使用方法：

1 canal的原理是基于mysql binlog技术，所以这里一定需要开启mysql的binlog写入功能
开启mysql服务： service mysql start （或者 systemctl start mysqld.service）

2 在mysql里面添加以下的相关用户和权限

1 CREATE USER 'canal'@'%' IDENTIFIED BY 'canal';
2 GRANT SHOW VIEW, SELECT, REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'canal'@'%';
3 FLUSH PRIVILEGES;

3 下载安装Canal服务
下载地址：
https://github.com/alibaba/canal/releases

（1）下载之后，放到目录中，解压文件

cd /usr/local/canal

canal.deployer-1.1.4.tar.gz

tar zxvf canal.deployer-1.1.4.tar.gz
4 修改配置文件


vi conf/example/instance.properties
1
#需要改成自己的数据库信息
2
canal.instance.master.address=192.168.44.132:3306
3
4
#需要改成自己的数据库用户名与密码
5
6
canal.instance.dbUsername=canal
7
canal.instance.dbPassword=canal
8
9
#需要改成同步的数据库表规则，例如只是同步一下表
10
#canal.instance.filter.regex=.*\\..*
11
canal.instance.filter.regex=guli_ucenter.ucenter_member

然后启动 sh bin/startup.sh
在这里插入图片描述
5 接下来创建一个微服务用于启动canal做数据同步
(1) 引入依赖

<dependencies>
2
    <dependency>
3
        <groupId>org.springframework.boot</groupId>
4
        <artifactId>spring-boot-starter-web</artifactId>
5
    </dependency>
6
7
    <!--mysql-->
8
    <dependency>
9
        <groupId>mysql</groupId>
10
        <artifactId>mysql-connector-java</artifactId>
11
    </dependency>
12
13
    <dependency>
14
        <groupId>commons-dbutils</groupId>
15
        <artifactId>commons-dbutils</artifactId>
16
    </dependency>
17
18
    <dependency>
19
        <groupId>org.springframework.boot</groupId>
20
        <artifactId>spring-boot-starter-jdbc</artifactId>
21
    </dependency>
22
23
    <dependency>
24
        <groupId>com.alibaba.otter</groupId>
25
        <artifactId>canal.client</artifactId>
26
    </dependency>
27
</dependencies>

（2）写入配置文件


# 服务端口
2
server.port=10000
3
# 服务名
4
spring.application.name=canal-client
5
6
# 环境设置：dev、test、prod
7
spring.profiles.active=dev
8
9
# mysql数据库连接
10
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
11
spring.datasource.url=jdbc:mysql://localhost:3306/guli?serverTimezone=GMT%2B8
12
spring.datasource.username=root
13
spring.datasource.password=root

（3）编写客户端程序

package com.atguigu.canal.client;

import com.alibaba.otter.canal.client.CanalConnector;
import com.alibaba.otter.canal.client.CanalConnectors;
import com.alibaba.otter.canal.protocol.CanalEntry.*;
import com.alibaba.otter.canal.protocol.Message;
import com.google.protobuf.InvalidProtocolBufferException;
import org.apache.commons.dbutils.DbUtils;
import org.apache.commons.dbutils.QueryRunner;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import javax.sql.DataSource;
import java.net.InetSocketAddress;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Iterator;
import java.util.List;
import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;

@Component
public class CanalClient {

    //sql队列
    private Queue<String> SQL_QUEUE = new ConcurrentLinkedQueue<>();

    @Resource
    private DataSource dataSource;

    /**
     * canal入库方法
     */
    public void run() {

        CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress("192.168.44.132",
                11111), "example", "", "");
        int batchSize = 1000;
        try {
            connector.connect();
            connector.subscribe(".*\\..*");
            connector.rollback();
            try {
                while (true) {
                    //尝试从master那边拉去数据batchSize条记录，有多少取多少
                    Message message = connector.getWithoutAck(batchSize);
                    long batchId = message.getId();
                    int size = message.getEntries().size();
                    if (batchId == -1 || size == 0) {
                        Thread.sleep(1000);
                    } else {
                        dataHandle(message.getEntries());
                    }
                    connector.ack(batchId);

                    //当队列里面堆积的sql大于一定数值的时候就模拟执行
                    if (SQL_QUEUE.size() >= 1) {
                        executeQueueSql();
                    }
                }
            } catch (InterruptedException e) {
                e.printStackTrace();
            } catch (InvalidProtocolBufferException e) {
                e.printStackTrace();
            }
        } finally {
            connector.disconnect();
        }
    }

    /**
     * 模拟执行队列里面的sql语句
     */
    public void executeQueueSql() {
        int size = SQL_QUEUE.size();
        for (int i = 0; i < size; i++) {
            String sql = SQL_QUEUE.poll();
            System.out.println("[sql]----> " + sql);

            this.execute(sql.toString());
        }
    }

    /**
     * 数据处理
     *
     * @param entrys
     */
    private void dataHandle(List<Entry> entrys) throws InvalidProtocolBufferException {
        for (Entry entry : entrys) {
            if (EntryType.ROWDATA == entry.getEntryType()) {
                RowChange rowChange = RowChange.parseFrom(entry.getStoreValue());
                EventType eventType = rowChange.getEventType();
                if (eventType == EventType.DELETE) {
                    saveDeleteSql(entry);
                } else if (eventType == EventType.UPDATE) {
                    saveUpdateSql(entry);
                } else if (eventType == EventType.INSERT) {
                    saveInsertSql(entry);
                }
            }
        }
    }

    /**
     * 保存更新语句
     *
     * @param entry
     */
    private void saveUpdateSql(Entry entry) {
        try {
            RowChange rowChange = RowChange.parseFrom(entry.getStoreValue());
            List<RowData> rowDatasList = rowChange.getRowDatasList();
            for (RowData rowData : rowDatasList) {
                List<Column> newColumnList = rowData.getAfterColumnsList();
                StringBuffer sql = new StringBuffer("update " + entry.getHeader().getTableName() + " set ");
                for (int i = 0; i < newColumnList.size(); i++) {
                    sql.append(" " + newColumnList.get(i).getName()
                            + " = '" + newColumnList.get(i).getValue() + "'");
                    if (i != newColumnList.size() - 1) {
                        sql.append(",");
                    }
                }
                sql.append(" where ");
                List<Column> oldColumnList = rowData.getBeforeColumnsList();
                for (Column column : oldColumnList) {
                    if (column.getIsKey()) {
                        //暂时只支持单一主键
                        sql.append(column.getName() + "=" + column.getValue());
                        break;
                    }
                }
                SQL_QUEUE.add(sql.toString());
            }
        } catch (InvalidProtocolBufferException e) {
            e.printStackTrace();
        }
    }

    /**
     * 保存删除语句
     *
     * @param entry
     */
    private void saveDeleteSql(Entry entry) {
        try {
            RowChange rowChange = RowChange.parseFrom(entry.getStoreValue());
            List<RowData> rowDatasList = rowChange.getRowDatasList();
            for (RowData rowData : rowDatasList) {
                List<Column> columnList = rowData.getBeforeColumnsList();
                StringBuffer sql = new StringBuffer("delete from " + entry.getHeader().getTableName() + " where ");
                for (Column column : columnList) {
                    if (column.getIsKey()) {
                        //暂时只支持单一主键
                        sql.append(column.getName() + "=" + column.getValue());
                        break;
                    }
                }
                SQL_QUEUE.add(sql.toString());
            }
        } catch (InvalidProtocolBufferException e) {
            e.printStackTrace();
        }
    }

    /**
     * 保存插入语句
     *
     * @param entry
     */
    private void saveInsertSql(Entry entry) {
        try {
            RowChange rowChange = RowChange.parseFrom(entry.getStoreValue());
            List<RowData> rowDatasList = rowChange.getRowDatasList();
            for (RowData rowData : rowDatasList) {
                List<Column> columnList = rowData.getAfterColumnsList();
                StringBuffer sql = new StringBuffer("insert into " + entry.getHeader().getTableName() + " (");
                for (int i = 0; i < columnList.size(); i++) {
                    sql.append(columnList.get(i).getName());
                    if (i != columnList.size() - 1) {
                        sql.append(",");
                    }
                }
                sql.append(") VALUES (");
                for (int i = 0; i < columnList.size(); i++) {
                    sql.append("'" + columnList.get(i).getValue() + "'");
                    if (i != columnList.size() - 1) {
                        sql.append(",");
                    }
                }
                sql.append(")");
                SQL_QUEUE.add(sql.toString());
            }
        } catch (InvalidProtocolBufferException e) {
            e.printStackTrace();
        }
    }

    /**
     * 入库
     * @param sql
     */
    public void execute(String sql) {
        Connection con = null;
        try {
            if(null == sql) return;
            con = dataSource.getConnection();
            QueryRunner qr = new QueryRunner();
            int row = qr.execute(con, sql);
            System.out.println("update: "+ row);
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DbUtils.closeQuietly(con);
        }
    }
}

（4）写入启动类

package com.atguigu.canal;


import com.atguigu.canal.client.CanalClient;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

import javax.annotation.Resource;

@SpringBootApplication
public class CanalApplication implements CommandLineRunner {
    @Resource
    private CanalClient canalClient;

    public static void main(String[] args) {
        SpringApplication.run(CanalApplication.class, args);
    }

    @Override
    public void run(String... strings) throws Exception {
        //项目启动，执行canal客户端监听
        canalClient.run();
    }
}