canal 入门（基于docker）

第一步：安装MySQL：(可以参考:https://my.oschina.net/amhuman/blog/1941540)

命令：

sudo docker run -it -d --restart unless-stopped -p : -h mysql --name mysql -e MYSQL_ROOT_PASSWORD=root   alanpeng/mysql5.-replication-docker

查看mysql 容器的id

sudo docker  inspect    [容器id]

开启MySQL 的binlog

（如果不是在docker中 vi /etc/mysql/my.cnf）

 vi   /etc/mysql/mysql.conf.d/mysqld.cnf

添加：

cd /etc/mysql

[mysqld]
log-bin=mysql-bin #添加这一行就ok
binlog-format=ROW #选择row模式
server_id=1 #配置mysql replaction需要定义，不能和canal的slaveId重复
#配置表名字不区分大小写
lower_case_table_names=1

解决  ＃sql 的模式//可以不操作

in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by

方案一：修改mysqld

sql_mode=STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION

方案2： 参考：https://www.cnblogs.com/ai10999/p/11449436.html

重新更新这个数据，取消这个only_full_group_by

set @@global.sql_mode ='STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION';
set @@session.sql_mode ='STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,

授权root 用户可以远程访问（运行sql）

grant all privileges  on *.* to root@'%' identified by "root";
flush privileges;

第二步：安装canal

2.1 命令：

 sudo docker run  -it  -d   --restart unless-stopped  -p :   canal/canal-server 

2.2 进入容器

sudo docker exec -it  [id]

2.3修改配置修改

应用参数：（参照：https://github.com/alibaba/canal/wiki/QuickStart）

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 = .\..

#################################################

第三步：写一个java springboot项目，消费benlog
pom依赖：

    <dependency>
            <groupId>com.alibaba.otter</groupId>
            <artifactId>canal.client</artifactId>
            <version>1.1.</version>
        </dependency>

写一个Test 方法：

package com.icil.canal;

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

import org.springframework.core.env.SystemEnvironmentPropertySource;

import com.alibaba.otter.canal.client.CanalConnector;
import com.alibaba.otter.canal.client.CanalConnectors;
import com.alibaba.otter.canal.common.utils.AddressUtils;
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 SimpleCanalClientExample {

    public static void main(String args[]) {
        // 创建链接
//        CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress(AddressUtils.getHostIp(),11111), "example", "", "");
        CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress(AddressUtils.getHostIp(),), "seatest", "", "");

        System.err.println(AddressUtils.getHostIp());

        int batchSize = ;
        int emptyCount = ;
        try {
            connector.connect();
            connector.subscribe(".*\\..*");
            connector.rollback();
            int totalEmptyCount = ;
            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 == - || size == ) {
                    emptyCount++;
                    System.out.println("empty count : " + emptyCount);
                    try {
                        Thread.sleep();
                    } catch (InterruptedException e) {
                    }
                } else {
                    emptyCount = ;
                    // System.out.printf("message[batchId=%s,size=%s] \n", batchId, size);

                    //打印变换的数据
                    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();
        }
    }

    //打印变化的数据
    private static void printEntry(List<Entry> entrys) {
        for (Entry entry : entrys) {
            //表示在一个事务中的数据
            if (entry.getEntryType() == EntryType.TRANSACTIONBEGIN || entry.getEntryType() == EntryType.TRANSACTIONEND) {
                continue;
            }

            RowChange rowChage = null;
            try {
                //获取每一行的数据
                rowChage = RowChange.parseFrom(entry.getStoreValue());
            } catch (Exception e) {
                throw new RuntimeException("ERROR ## parser of eromanga-event has an error , data:" + entry.toString(),
                                           e);
            }
            //获取时间类型// update insert delete
            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("----改变之前---&gt; before");
                    printColumn(rowData.getBeforeColumnsList());
                    System.out.println("----修改之后---&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());
        }
    }

}

配置多个instans : (复制 example ,删除 h2.mv.db  和  meta,dat ,避免出现找不到 初始位置问题)