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flume 读取kafka 数据

news 来源：原创 2024/4/26 13:02:47

本文介绍flume读取kafka数据的方法

代码：

/*******************************************************************************
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*******************************************************************************/
package org.apache.flume.source.kafka;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import kafka.consumer.ConsumerIterator;
import kafka.consumer.KafkaStream;
import kafka.javaapi.consumer.ConsumerConnector;
import kafka.message.Message;

import kafka.message.MessageAndMetadata;
import org.apache.flume.*;
import org.apache.flume.conf.Configurable;
import org.apache.flume.conf.ConfigurationException;
import org.apache.flume.event.SimpleEvent;
import org.apache.flume.source.AbstractSource;
import org.apache.flume.source.SyslogParser;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
* A Source for Kafka which reads messages from kafka. I use this in company production environment
* and its performance is good. Over 100k messages per second can be read from kafka in one source.<p>
* <tt>zookeeper.connect: </tt> the zookeeper ip kafka use.<p>
* <tt>topic: </tt> the topic to read from kafka.<p>
* <tt>group.id: </tt> the groupid of consumer group.<p>
*/
public class KafkaSource extends AbstractSource implements Configurable, PollableSource {
   private static final Logger log = LoggerFactory.getLogger(KafkaSource.class);
   private ConsumerConnector consumer;
   private ConsumerIterator<byte[], byte[]> it;
   private String topic;

   public Status process() throws EventDeliveryException {
       List<Event> eventList = new ArrayList<Event>();
        MessageAndMetadata<byte[],byte[]> message;
       Event event;
       Map<String, String> headers;
        String strMessage;
        try {
           if(it.hasNext()) {
               message = it.next();
               event = new SimpleEvent();
               headers = new HashMap<String, String>();
               headers.put("timestamp", String.valueOf(System.currentTimeMillis()));

                strMessage = String.valueOf(System.currentTimeMillis()) + "|" + new String(message.message());
                log.debug("Message: {}", strMessage);

                event.setBody(strMessage.getBytes());
                //event.setBody(message.message());
               event.setHeaders(headers);
               eventList.add(event);
           }
           getChannelProcessor().processEventBatch(eventList);
           return Status.READY;
       } catch (Exception e) {
           log.error("KafkaSource EXCEPTION, {}", e.getMessage());
           return Status.BACKOFF;
       }
   }

   public void configure(Context context) {
       topic = context.getString("topic");
       if(topic == null) {
           throw new ConfigurationException("Kafka topic must be specified.");
       }
       try {
           this.consumer = KafkaSourceUtil.getConsumer(context);
       } catch (IOException e) {
           log.error("IOException occur, {}", e.getMessage());
       } catch (InterruptedException e) {
           log.error("InterruptedException occur, {}", e.getMessage());
       }
       Map<String, Integer> topicCountMap = new HashMap<String, Integer>();
       topicCountMap.put(topic, new Integer(1));
       Map<String, List<KafkaStream<byte[], byte[]>>> consumerMap = consumer.createMessageStreams(topicCountMap);
       if(consumerMap == null) {
           throw new ConfigurationException("topicCountMap is null");
       }
       List<KafkaStream<byte[], byte[]>> topicList = consumerMap.get(topic);
       if(topicList == null || topicList.isEmpty()) {
           throw new ConfigurationException("topicList is null or empty");
       }
        KafkaStream<byte[], byte[]> stream = topicList.get(0);
        it = stream.iterator();
   }

   @Override
   public synchronized void stop() {
       consumer.shutdown();
       super.stop();
   }

}

/*******************************************************************************
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*******************************************************************************/
package org.apache.flume.source.kafka;

import java.io.IOException;
import java.util.Map;
import java.util.Properties;

import com.google.common.collect.ImmutableMap;
import kafka.consumer.Consumer;
import kafka.consumer.ConsumerConfig;
import kafka.javaapi.consumer.ConsumerConnector;

import org.apache.flume.Context;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class KafkaSourceUtil {
   private static final Logger log = LoggerFactory.getLogger(KafkaSourceUtil.class);

   public static Properties getKafkaConfigProperties(Context context) {
       log.info("context={}",context.toString());
       Properties props = new Properties();
        ImmutableMap<String, String> contextMap = context.getParameters();
        for (Map.Entry<String,String> entry : contextMap.entrySet()) {
            String key = entry.getKey();
            if (!key.equals("type") && !key.equals("channel")) {
                props.setProperty(entry.getKey(), entry.getValue());
                log.info("key={},value={}", entry.getKey(), entry.getValue());
            }
        }
       return props;
   }
   public static ConsumerConnector getConsumer(Context context) throws IOException, InterruptedException {
       ConsumerConfig consumerConfig = new ConsumerConfig(getKafkaConfigProperties(context));
       ConsumerConnector consumer = Consumer.createJavaConsumerConnector(consumerConfig);
       return consumer;
   }
}

配置文件：（ /etc/flume/conf/flume-kafka-file.properties）

agent_log.sources = kafka0
agent_log.channels = ch0
agent_log.sinks = sink0

agent_log.sources.kafka0.channels = ch0
agent_log.sinks.sink0.channel = ch0

agent_log.sources.kafka0.type = org.apache.flume.source.kafka.KafkaSource
agent_log.sources.kafka0.zookeeper.connect = node3:2181,node4:2181,node5:2181
agent_log.sources.kafka0.topic = kkt-test-topic
agent_log.sources.kafka0.group.id= test

agent_log.channels.ch0.type = memory
agent_log.channels.ch0.capacity = 2048
agent_log.channels.ch0.transactionCapacity = 1000

agent_log.sinks.sink0.type=file_roll
agent_log.sinks.sink0.sink.directory=/data/flumeng/data/test
agent_log.sinks.sink0.sink.rollInterval=300

启动脚本：

sudo su -l -s /bin/bash flume -c '/usr/lib/flume/bin/flume-ng agent --conf /etc/flume/conf --conf-file /etc/flume/conf/flume-kafka-file.properties -name agent_log -Dflume.root.logger=INFO,console '

注意：红色字体的功能是对原来数据增加时间戳

版本号 flume-1.4.0.2.1.1.0 + kafka2.8.0-0.8.0

參考资料：https://github.com/baniuyao/flume-kafka

编译用到的库：

flume-ng-configuration-1.4.0.2.1.1.0-385

flume-ng-core-1.4.0.2.1.1.0-385

flume-ng-sdk-1.4.0.2.1.1.0-385

flume-tools-1.4.0.2.1.1.0-385

guava-11.0.2

kafka_2.8.0-0.8.0

log4j-1.2.15

scala-compiler