springboot整合canal数据同步

Canal介绍

1.1、应用场景

在微服务中，我们采取了feign进行服务间通信，通过访问其他模块的数据来完成当前模块的任务，这样耦合度高，效率相对较低，目前我采取另一种实现方式，通过实时同步数据库表的方式实现，例如我们要统计每天注册与登录人数，我们只需把会员表同步到统计库中，实现本地统计就可以了，这样效率更高，耦合度更低，Canal就是一个很好的数据库同步工具。

1.2、Canal简单介绍

canal是阿里巴巴旗下的一款开源项目，纯Java开发。基于数据库增量日志解析，提供增量数据订阅&消费，目前主要支持了MySQL。

Canal环境搭建

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.

2.1.开启mysql服务：

service mysql start

或者

systemctl start mysqld.service

2.2、检查binlog功能是否有开启

show variables like 'log_bin';

2.3、如果显示状态为OFF表示该功能未开启，开启binlog功能

修改 mysql 的配置文件 my.cnf

vi /etc/my.cnf 

追加内容：

#binlog文件名
log-bin=mysql-bin
#选择row模式
binlog_format=ROW
#mysql实例id,不能和canal的slaveId重复
server_id=1

2.4、重启 mysql：

systemctl restart mysqld.service

2.5、查看是否开启，ON表示开启

2.6、查看是否开启MySQL远程连接

show databases;

use mysql;

select `user`,authentication_string,`Host` from `user`;

2.7、有%号表示开启远程连接，是localhost只能本地连接

设置远程连接，%号即远程连接，IDENTIFIED BY后面跟的自己密码

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'zzybzb';

刷新，重启

flush privileges;

再次查看

2.8、本地和Linux服务器创建一个相同的数据库和表，用来测试同步数据

下载安装canal

3.1、下载

下载地址：https://github.com/alibaba/canal/releases/

3.2、上传到服务器，自己创建个目录来放

3.3、解压

3.4、修改配置文件

vi conf/example/instance.properties

#需要改成自己的数据库信息
canal.instance.master.address=192.168.44.132:3306

#需要改成自己的数据库用户名与密码
canal.instance.dbUsername=root
canal.instance.dbPassword=zzybzb

#需要改成同步的数据库表规则，例如只是同步一下表
#canal.instance.filter.regex=.*\\..*
canal.instance.filter.regex=canal_test.member

3.5、进入bin目录，启动canal

./startup.sh

springboot整合canal

4.1、引入依赖

<dependencies>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>

        
        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
        dependency>

        <dependency>
            <groupId>commons-dbutilsgroupId>
            <artifactId>commons-dbutilsartifactId>
        dependency>

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-jdbcartifactId>
        dependency>

        <dependency>
            <groupId>com.alibaba.ottergroupId>
            <artifactId>canal.clientartifactId>
        dependency>
    dependencies>

4.2、application配置文件

# 服务端口
server.port=10000
# 服务名
spring.application.name=canal-client

# 环境设置：dev、test、prod
spring.profiles.active=dev

# mysql数据库连接
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/canal_test?serverTimezone=GMT%2B8
spring.datasource.username=root
spring.datasource.password=zzybzb

4.3、canalClient类

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("192.168.64.131",
                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);
        }
    }
}

4.4、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();
    }
}

4.5、启动后，Linux服务器的数据库改变，本地的数据也会跟着同步

我启动报错，就没有测试的下文了

启动bug

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2022-09-21 21:44:56.890 ERROR 2300 --- [           main] o.s.boot.SpringApplication               : Application run failed

java.lang.IllegalStateException: Failed to execute CommandLineRunner
	at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:787) [spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
	at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:768) [spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:322) [spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) [spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) [spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
	at com.atguigu.canal.CanalApplication.main(CanalApplication.java:16) [classes/:na]
Caused by: com.alibaba.otter.canal.protocol.exception.CanalClientException: java.net.ConnectException: Connection refused: connect
	at com.alibaba.otter.canal.client.impl.SimpleCanalConnector.doConnect(SimpleCanalConnector.java:190) ~[canal.client-1.1.0.jar:na]
	at com.alibaba.otter.canal.client.impl.SimpleCanalConnector.connect(SimpleCanalConnector.java:114) ~[canal.client-1.1.0.jar:na]
	at com.atguigu.canal.client.CanalClient.run(CanalClient.java:40) ~[classes/:na]
	at com.atguigu.canal.CanalApplication.run(CanalApplication.java:22) [classes/:na]
	at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:784) [spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
	... 5 common frames omitted
Caused by: java.net.ConnectException: Connection refused: connect
	at sun.nio.ch.Net.connect0(Native Method) ~[na:1.8.0_71]
	at sun.nio.ch.Net.connect(Net.java:454) ~[na:1.8.0_71]
	at sun.nio.ch.Net.connect(Net.java:446) ~[na:1.8.0_71]
	at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:648) ~[na:1.8.0_71]
	at com.alibaba.otter.canal.client.impl.SimpleCanalConnector.doConnect(SimpleCanalConnector.java:149) ~[canal.client-1.1.0.jar:na]
	... 9 common frames omitted

5.1、可能原因：防火墙没关

5.2、11111端口号没开放

开放端口

firewall-cmd --zone=public --add-port=11111/tcp --permanent

配置立即生效：

firewall-cmd --reload

开放端口存在的问题：FirewallD is not running

开启防火墙：

systemctl start firewalld

5.3、配置文件不对

bug还没解决，未结束。。。