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Canal GitHub：https://github.com/alibaba/canal#readme
实时采集工具canal：利用mysql主从复制的原理，slave定期读取master的binarylog对binarylog进行解析。
canal工作原理
canal模拟MySQL slave的交互协议，伪装自己为MySQL slave,向MySQL master发送dump协议
MySQL master收到dump请求，开始推送binary log给slave(即canal)
canal解析binary log对像（原始为bye流）

官网配置：https://github.com/alibaba/canal/wiki/QuickStart
1.在mysql中开启binlog日志功能
mysql上配置

linux>vi /etc/my.cnf 
server-id=1
log-bin=mysql-bin
binlog_format=row
binlog-do-db=testdb	//指定数据库

2.重启mysql服务

linux>systemctl restart mysqld

3.查看binlog是否生效：

linux>ls /var/lib/mysql

4.解压canal压缩包

linux>tar -zxvf canal-* -C  canal

5.数据库设置
登陆mysql

mysql>GRANT SELECT, REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'canal'@'%' IDENTIFIED BY 'canal';
mysql>flush privileges;

6.配置文件
1.修改canal.properties配置文件

linux>vi conf/canal.properties
canal.instance.parser.parallelThreadSize = 1

2.修改instance.properties配置文件

linux>vi  conf/example/instance.properties
canal.instance.mysql.slaveId=21
canal.instance.master.address=192.168.58.203:3306

7.启动服务并查看进程

linux>bin/startup.sh

linux>jps

xxxx CanalLauncher

查看日志

linux>cat /opt/install/canal/logs/canal/canal.log

idea客户端
pom.xml

 <dependency>
            <groupId>com.alibaba.otter</groupId>
            <artifactId>canal.client</artifactId>
            <version>1.1.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.kafka</groupId>
            <artifactId>kafka-clients</artifactId>
            <version>2.4.1</version>
        </dependency>

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.CanalEntry;
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 CanalClientDemo {
    public static void main(String args[]) {
        // 创建链接
        CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress("192.168.58.203）",
                11111), "example", "", "");
        int batchSize = 1000;
        int emptyCount = 0;
        try {
        //testdb库中的所有表
            connector.connect();
            connector.subscribe("testdb.*");
            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] 
", 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<CanalEntry.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());
        }
    }
}

注意：canal只能在java8中运行，如果canal进程CanalLauncher起不来，检查本地java环境
CanalClientDemo运行提示拒绝连接，检查脚本中的连接地址是不是运行canal的主机 CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress(“192.168.58.203（canal））”,
xxxx");

Canal kafka github 配置官网：github.com/alibaba/canal/wiki/Canal-Kafka-RocketMQ-QuickStart

使用canal将数据同步到kafka上
#重新解压一个canal到nodefour上进行配置
1.修改canal.properties配置文件

linux>vi canal.properties

canal.serverMode = kafka
canal.instance.parser.parallel = false
canal.mq.servers = 192.168.58.201:9092,192.168.58.202:9092,192.168.58.203:9092

2.修改instance.properties配置文件

linux>vi instance.properties

canal.instance.mysql.slaveId=21
canal.instance.master.address=192.168.58.203:3306
canal.mq.topic=example

3.可以创建topic，也可以不创建

在kafka上启动一个消费者

bin/kafka-console-consumer.sh --topic example --from-beginning --bootstrap-server 192.168.58.201:9092,192.168.58.202:9092,192.168.58.203:9092

启动 canal

linux>bin/startup.sh

结果：