【canal】canal hello world

具体参考：
https://github.com/alibaba/canal/wiki/QuickStart

准备
对于自建 MySQL , 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

[mysqld]
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
注意：针对阿里云 RDS for MySQL , 默认打开了 binlog , 并且账号默认具有 binlog dump 权限 , 不需要任何权限或者 binlog 设置,可以直接跳过这一步
授权 canal 链接 MySQL 账号具有作为 MySQL slave 的权限, 如果已有账户可直接 grant

CREATE USER canal IDENTIFIED BY 'canal'; 
GRANT SELECT, REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'canal'@'%';
-- GRANT ALL PRIVILEGES ON *.* TO 'canal'@'%' ;
FLUSH PRIVILEGES;
启动

官方指导的配置是有问题的，启动canal-server会报以下错误：
^@2020-06-29 08:27:52.320 [destination = example , address = /127.0.0.1:3306 , EventParser] ERROR c.a.otter.canal.parse.inbound.mysql.MysqlEventParser - dump address /127.0.0.1:3306 has an error, retrying. caused by
java.io.IOException: connect /127.0.0.1:3306 failure:java.io.IOException: Unexpected End Stream

将
log-bin=【有权限的绝对路径】 # 开启 binlog
重启mysql后生效




下载 canal, 访问 release 页面 , 选择需要的包下载, 如以 1.0.17 版本为例

wget https://github.com/alibaba/canal/releases/download/canal-1.0.17/canal.deployer-1.0.17.tar.gz
解压缩

mkdir /tmp/canal
tar zxvf canal.deployer-$version.tar.gz  -C /tmp/canal
解压完成后，进入 /tmp/canal 目录，可以看到如下结构
drwxr-xr-x 2 jianghang jianghang  136 2013-02-05 21:51 bin
drwxr-xr-x 4 jianghang jianghang  160 2013-02-05 21:51 conf
drwxr-xr-x 2 jianghang jianghang 1.3K 2013-02-05 21:51 lib
drwxr-xr-x 2 jianghang jianghang   48 2013-02-05 21:29 logs
配置修改

vi conf/example/instance.properties
## 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 = .\*\\\\..\*
canal.instance.connectionCharset 代表数据库的编码方式对应到 java 中的编码类型，比如 UTF-8，GBK , ISO-8859-1
如果系统是1个 cpu，需要将 canal.instance.parser.parallel 设置为 false
启动

sh bin/startup.sh
查看 server 日志

vi logs/canal/canal.log</pre>
2013-02-05 22:45:27.967 [main] INFO  com.alibaba.otter.canal.deployer.CanalLauncher - ## start the canal server.
2013-02-05 22:45:28.113 [main] INFO  com.alibaba.otter.canal.deployer.CanalController - ## start the canal server[10.1.29.120:11111]
2013-02-05 22:45:28.210 [main] INFO  com.alibaba.otter.canal.deployer.CanalLauncher - ## the canal server is running now ......
查看 instance 的日志

vi logs/example/example.log
2013-02-05 22:50:45.636 [main] INFO  c.a.o.c.i.spring.support.PropertyPlaceholderConfigurer - Loading properties file from class path resource [canal.properties]
2013-02-05 22:50:45.641 [main] INFO  c.a.o.c.i.spring.support.PropertyPlaceholderConfigurer - Loading properties file from class path resource [example/instance.properties]
2013-02-05 22:50:45.803 [main] INFO  c.a.otter.canal.instance.spring.CanalInstanceWithSpring - start CannalInstance for 1-example
2013-02-05 22:50:45.810 [main] INFO  c.a.otter.canal.instance.spring.CanalInstanceWithSpring - start successful....
关闭

sh bin/stop.sh


客户端：
package com.alibaba.test.steed.utils;

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


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;


public class SimpleCanalClientExample {


    public static void main(String args[]) {
        // 创建链接
        CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress(AddressUtils.getHostIp(),
                11111), "example", "", "");
//        11111), "example", "", "");
        int batchSize = 1000;
        int emptyCount = 0;
        try {
            connector.connect();
            connector.subscribe(".*\\..*");
            connector.rollback();
            int totalEmptyCount = 120;
            while (emptyCount < totalEmptyCount) {
                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
            }

            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("================&gt; 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("-------&gt; before");
                    printColumn(rowData.getBeforeColumnsList());
                    System.out.println("-------&gt; 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());
        }
    }

}


客户端消费：
empty count : 113
empty count : 114
================&gt; binlog[mysql-bin.000001:382] , name[example,tb_user] , eventType : INSERT
id : 1    update=false
aid : 1    update=false
name : 1111    update=false
passwd :     update=false
telephone :     update=false
icon :     update=false
email :     update=false
title :     update=false
status : 0    update=false
create_time : 2000-01-01 00:00:00    update=false
update_time : 2020-06-29 08:32:52    update=false
empty count : 1
empty count : 2