canal使用

2021-07-24 09:03:13 作者：互联网

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

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

配置修改

D:\canal.deployer-1.1.5\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

bin\startup.bat # windows
sh bin/startup.sh # linux

查看日志，主要包括server日志和instance日志

# 查看 server 日志
D:\canal.deployer-1.1.5\logs\canal\canal.log  # windows3
vi logs/canal/canal.log

# 查看 instance 的日志
D:\canal.deployer-1.1.5\logs\example\example.log
vi logs/example/example.log

关闭

sh bin/stop.sh  # linux

常见的错误

问题1：caching_sha2_password Auth failed

原因：

使用mysql版本为8.0,而创建用户时默认的密码加密方式为caching_sha2_password，所以修改为mysql_native_password 就行，首先找到conf/example/instance.properties文件中，canal.instance.dbUsername对应的用户名为授权的用户名，我这边canal的用户名和密码都是： canal

myql8.0版本的密码加密方式为caching_sha2_password，所以修改为mysql_native_password 就行并重新更新密码

ALTER USER 'canal'@'%' IDENTIFIED WITH mysql_native_password BY 'canal'; #更新一下用户密码
FLUSH PRIVILEGES; #刷新权限

2021-07-23 11:57:03.568 [destination = example , address = /127.0.0.1:3306 , EventParser] ERROR c.a.o.c.p.inbound.mysql.rds.RdsBinlogEventParserProxy - dump address /127.0.0.1:3306 has an error, retrying. caused by 
com.alibaba.otter.canal.parse.exception.CanalParseException: java.io.IOException: connect /127.0.0.1:3306 failure
Caused by: java.io.IOException: connect /127.0.0.1:3306 failure
	at com.alibaba.otter.canal.parse.driver.mysql.MysqlConnector.connect(MysqlConnector.java:85) ~[canal.parse.driver-1.1.5.jar:na]
	at com.alibaba.otter.canal.parse.inbound.mysql.MysqlConnection.connect(MysqlConnection.java:90) ~[canal.parse-1.1.5.jar:na]
	at com.alibaba.otter.canal.parse.inbound.mysql.MysqlEventParser.preDump(MysqlEventParser.java:86) ~[canal.parse-1.1.5.jar:na]
	at com.alibaba.otter.canal.parse.inbound.AbstractEventParser$1.run(AbstractEventParser.java:176) ~[canal.parse-1.1.5.jar:na]
	at java.lang.Thread.run(Unknown Source) [na:1.8.0_291]
Caused by: java.io.IOException: caching_sha2_password Auth failed
	at com.alibaba.otter.canal.parse.driver.mysql.MysqlConnector.negotiate(MysqlConnector.java:260) ~[canal.parse.driver-1.1.5.jar:na]
	at com.alibaba.otter.canal.parse.driver.mysql.MysqlConnector.connect(MysqlConnector.java:82) ~[canal.parse.driver-1.1.5.jar:na]
	... 4 common frames omitted

测试一下

添加pom依赖

<dependency>
    <groupId>com.alibaba.otter</groupId>
    <artifactId>canal.client</artifactId>
    <version>1.1.5</version>
</dependency>

SimpleCanalClientExample.java

package io.github.forezp.es;

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", "", "");
        int batchSize = 1000;
        int emptyCount = 0;
        try {
            // 打开连接
            connector.connect();
            // 订阅数据库表,全部表
            connector.subscribe(".*\\..*");
            // 回滚到未进行ack的地方，下次fetch的时候，可以从最后一个没有ack的地方开始拿
            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());
        }
    }

}

标签：canal,java,alibaba,instance,使用,com,otter
来源： https://blog.csdn.net/jiangxwa/article/details/119031817