在centOS7上搭建canal服务

使用canal解析mysql的增量日志，记录一下搭建过程。

根据官方文档，需要先开启 Binlog 写入功能，配置 binlog-format 为 ROW 模式，my.cnf 中配置如下：

log-bin=mysql-bin # 开启 binlog
binlog-format=ROW # 选择 ROW 模式
server_id=1 # 配置 MySQL replaction 需要定义，不要和 canal 的 slaveId 重复

 保存修改重启mysql;

 下载压缩包，这个过程比较慢，我这才10几k每秒。也可以在github上下载再上传。

wget https://github.com/alibaba/canal/releases/download/canal-1.1.4/canal.deployer-1.1.4.tar.gz

解压

tar zxvf canal.deployer-1.1.4.tar.gz

 

 解压完成后的目录结构

 

修改conf下的配置文件

vim conf/example/instance.properties

 配置说明

## mysql serverId
canal.instance.mysql.slaveId = 1234
#position info，需要改成自己的数据库信息
canal.instance.master.address = 127.0.0.1:3306 
canal.instance.master.journal.name = 
canal.instance.master.position = 
canal.instance.master.timestamp = 
#canal.instance.standby.address = 
#canal.instance.standby.journal.name =
#canal.instance.standby.position = 
#canal.instance.standby.timestamp = 
#username/password，需要改成自己的数据库信息
canal.instance.dbUsername = canal  
canal.instance.dbPassword = canal
canal.instance.defaultDatabaseName =
canal.instance.connectionCharset = UTF-8
#table regex
canal.instance.filter.regex = .\*\\\\..\*

 启动服务：

sh bin/startup.sh

 查看server日志：

vi logs/canal/canal.log

查看 instance 的日志

vi logs/example/example.log

 

服务到这里就搭建成功了。下一步我们来编写客户端代码，获取解析后的日志信息。

 
            com.alibaba.otter
            canal.client
            1.1.4
        

package com.dwl;

import com.alibaba.otter.canal.client.CanalConnectors;
import com.alibaba.otter.canal.client.CanalConnector;
import com.alibaba.otter.canal.common.utils.AddressUtils;
import com.alibaba.otter.canal.protocol.Message;
import com.alibaba.otter.canal.protocol.CanalEntry.Column;
import com.alibaba.otter.canal.protocol.CanalEntry.Entry;
import com.alibaba.otter.canal.protocol.CanalEntry.EntryType;
import com.alibaba.otter.canal.protocol.CanalEntry.EventType;
import com.alibaba.otter.canal.protocol.CanalEntry.RowChange;
import com.alibaba.otter.canal.protocol.CanalEntry.RowData;

import java.net.InetSocketAddress;
import java.util.List;

/**
 * @program: canal
 * @description:
 * @author: daiwenlong
 * @create: 2020-04-06 19:44
 **/
public class CanalClient {

    public static void main(String args[]) {
        // 创建链接
        CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress("47.97.160.232",
                11111), "example", "", "");
        int batchSize = 1000;
        int emptyCount = 0;
        try {
            connector.connect();
            connector.subscribe(".*\\..*");
            connector.rollback();
            while (true) {
                Message message = connector.getWithoutAck(batchSize); // 获取指定数量的数据
                long batchId = message.getId();
                int size = message.getEntries().size();
                if (batchId == -1 || size == 0) {
                    emptyCount++;
                    System.out.println("empty count : " + emptyCount);
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException e) {
                    }
                } else {
                    emptyCount = 0;
                    // System.out.printf("message[batchId=%s,size=%s] \n", batchId, size);
                    printEntry(message.getEntries());
                }

                connector.ack(batchId); // 提交确认
                // connector.rollback(batchId); // 处理失败, 回滚数据
            }
        } finally {
            connector.disconnect();
        }
    }

    private static void printEntry(List entrys) {
        for (Entry entry : entrys) {
            if (entry.getEntryType() == EntryType.TRANSACTIONBEGIN || entry.getEntryType() == EntryType.TRANSACTIONEND) {
                continue;
            }

            RowChange rowChage = null;
            try {
                rowChage = RowChange.parseFrom(entry.getStoreValue());
            } catch (Exception e) {
                throw new RuntimeException("ERROR ## parser of eromanga-event has an error , data:" + entry.toString(),
                        e);
            }

            EventType eventType = rowChage.getEventType();
            System.out.println(String.format("================> binlog[%s:%s] , name[%s,%s] , eventType : %s",
                    entry.getHeader().getLogfileName(), entry.getHeader().getLogfileOffset(),
                    entry.getHeader().getSchemaName(), entry.getHeader().getTableName(),
                    eventType));

            for (RowData rowData : rowChage.getRowDatasList()) {
                if (eventType == EventType.DELETE) {
                    printColumn(rowData.getBeforeColumnsList());
                } else if (eventType == EventType.INSERT) {
                    printColumn(rowData.getAfterColumnsList());
                } else {
                    System.out.println("-------> before");
                    printColumn(rowData.getBeforeColumnsList());
                    System.out.println("-------> after");
                    printColumn(rowData.getAfterColumnsList());
                }
            }
        }
    }

    private static void printColumn(List columns) {
        for (Column column : columns) {
            System.out.println(column.getName() + " : " + column.getValue() + "    update=" + column.getUpdated());
        }
    }
}

查看控制台结果

 修改一条数据，查看结果

UPDATE `guest` SET `create_time`='2020-04-06 20:01:23' WHERE (`id`='3')

 删除一条数据

DELETE FROM `guest` WHERE (`id`='4')

新增一条数据

INSERT INTO `guest` (`id`, `user_id`, `status`, `create_time`) VALUES ('11', '2', '', '2020-04-03 20:07:04')