关于canal

canal官网
  • 安装mysql

MySQL5.7安装与配置
添加配置

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,建议配置binlog模式为row

vim /etc/my.cof

[mysqld]
log-bin=mysql-bin 
binlog-format=ROW
server_id=1
添加权限,canal的原理是模拟自己为mysql slave,所以这里一定需要做为mysql slave的相关权限.
# 该步骤如果有问题 可以直接刷新,使用:FLUSH PRIVILEGES;
1、CREATE USER canal IDENTIFIED BY 'canal';  
2、GRANT SELECT, REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'canal'@'%';
-- GRANT ALL PRIVILEGES ON *.* TO 'canal'@'%' ;
3、FLUSH PRIVILEGES;
  • canal 安装和配置

canal下载

进入/opt/canal,创建 canal目录 进入该目录
[root@localhost canal]#wget https://github.com/alibaba/canal/releases/download/canal-1.1.3/canal.adapter-1.1.3.tar.gz
[root@localhost canal]# ls
bin  conf  lib  logs
[root@localhost canal]# 
配置 vi conf/example/instance.properties
 canal.instance.dbUsername=数据库用户
 canal.instance.dbPassword=密码
 canal.instance.defaultDatabaseName=数据库名称
运行&关闭
[root@localhost canal]# bin/startup.sh 
[root@localhost canal]# bin/stop.sh 
查看日志
[root@localhost canal]# tail -f logs/canal/canal.log 
2019-06-11 01:13:10.143 [main] INFO  com.alibaba.otter.canal.deployer.CanalController - ## start the canal server[172.17.0.1:11111]
2019-06-11 01:13:11.240 [main] WARN  o.s.beans.GenericTypeAwarePropertyDescriptor - Invalid JavaBean property 'connectionCharset' being accessed! Ambiguous write methods found next to actually used [public void com.alibaba.otter.canal.parse.inbound.mysql.AbstractMysqlEventParser.setConnectionCharset(java.nio.charset.Charset)]: [public void com.alibaba.otter.canal.parse.inbound.mysql.AbstractMysqlEventParser.setConnectionCharset(java.lang.String)]
2019-06-11 01:13:11.597 [main] ERROR com.alibaba.druid.pool.DruidDataSource - testWhileIdle is true, validationQuery not set
2019-06-11 01:13:11.996 [main] WARN  c.a.o.canal.parse.inbound.mysql.dbsync.LogEventConvert - --> init table filter : ^.*\..*$
2019-06-11 01:13:11.996 [main] WARN  c.a.o.canal.parse.inbound.mysql.dbsync.LogEventConvert - --> init table black filter : 
2019-06-11 01:13:12.252 [destination = example , address = /127.0.0.1:3306 , EventParser] WARN  c.a.o.c.p.inbound.mysql.rds.RdsBinlogEventParserProxy - ---> begin to find start position, it will be long time for reset or first position
2019-06-11 01:13:12.274 [destination = example , address = /127.0.0.1:3306 , EventParser] WARN  c.a.o.c.p.inbound.mysql.rds.RdsBinlogEventParserProxy - prepare to find start position just last position
 {"identity":{"slaveId":-1,"sourceAddress":{"address":"localhost","port":3306}},"postion":{"gtid":"","included":false,"journalName":"mysql-bin.000023","position":6421,"serverId":223344,"timestamp":1560240096000}}
2019-06-11 01:13:12.357 [main] INFO  com.alibaba.otter.canal.deployer.CanalStater - ## the canal server is running now ......
2019-06-11 01:13:12.787 [destination = example , address = /127.0.0.1:3306 , EventParser] WARN  c.a.o.c.p.inbound.mysql.rds.RdsBinlogEventParserProxy - ---> find start position successfully, EntryPosition[included=false,journalName=mysql-bin.000023,position=6421,serverId=223344,gtid=,timestamp=1560240096000] cost : 507ms , the next step is binlog dump
  • 客户端,创建maven项目,可以直接使用springboot

下官网示例

pom添加依赖包
<dependency>
    <groupId>com.alibaba.otter</groupId>
    <artifactId>canal.client</artifactId>
    <version>1.1.0</version>
</dependency>
java 代码
package com.elastic.search;

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

import com.alibaba.otter.canal.client.CanalConnector;
import com.alibaba.otter.canal.client.CanalConnectors;
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 com.alibaba.otter.canal.protocol.Message;

public class TestCanal {

    public static void main(String args[]) {
        // 创建链接
        CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress("192.168.177.128", 11111),
                "example", "", "");
        int batchSize = 1000;
        int emptyCount = 0;
        try {
            connector.connect();
            connector.subscribe(".*\\..*");
            connector.rollback();
            int totalEmtryCount = 2500;
            while (emptyCount < totalEmtryCount) {
                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) {
                        e.printStackTrace();
                    }
                } 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
            }

            System.out.println("empty too many times, exit");
        } finally {
            connector.disconnect();
        }
    }

    private static void printEntry(List<Entry> 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<Column> columns) {
        for (Column column : columns) {
            System.out.println(column.getName() + " : " + column.getValue() + "    update=" + column.getUpdated());
        }
    }
}
直接运行,在数据库触发新增,修改,删除 操作,你可以看到打印信息

reference

官方文档
阿里Canal安装和代码示例
不错的springboot导入ES的封装

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Last modification:February 13th, 2020 at 03:50 pm
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