kafka通过java api 获取当前消费组offset/logsize/lag信息，实现消费延迟监控

Posted 2022-10-17 没有梦想-何必远方

更新

注意此篇是针对使用旧版消费的方案， 旧版（0.8之前）offset信息存在zk，新版（0.9以后）存在topic中。如果不知道自己是什么版本的，请看这篇：
新旧版消费代码

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一般监控kafka消费情况我们可以使用现成的工具来查看，但如果发生大量延迟不能及时知道。所以问题就来了，怎么用java api 进行kafka的监控呢？

用过kafka都该知道 延迟量 lag = logSize(topic记录量) - offset(消费组消费进度)
所以我们获取到logSize / offset 就可以了。

鉴于这部分信息网上资料非常少，特地将代码抛出来。

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我使用的jar:

<groupId>org.apache.kafka</groupId>
<artifactId>kafka_2.11</artifactId>
<version>0.10.1.1</version>

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package com.fengjr.elk.web.write;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;
import java.util.Map.Entry;

import kafka.api.PartitionOffsetRequestInfo;
import kafka.common.ErrorMapping;
import kafka.common.OffsetMetadataAndError;
import kafka.common.TopicAndPartition;
import kafka.javaapi.*;
import kafka.javaapi.consumer.SimpleConsumer;
import kafka.network.BlockingChannel;

public class KafkaOffsetTools 

    public static void main(String[] args) 

        String topic = "app-log-all-beta";
        String broker = "10.255.73.160";
        int port = 9092;
        String group = "fengjr-elk-group-es";
        String clientId = "Client_app-log-all-beta_1";
        int correlationId = 0;
        BlockingChannel channel = new BlockingChannel(broker, port,
                BlockingChannel.UseDefaultBufferSize(),
                BlockingChannel.UseDefaultBufferSize(),
                5000 );
        channel.connect();

        List<String> seeds = new ArrayList<String>();
        seeds.add(broker);
        KafkaOffsetTools kot = new KafkaOffsetTools();

        TreeMap<Integer,PartitionMetadata> metadatas = kot.findLeader(seeds, port, topic);

        long sum = 0l;
        long sumOffset = 0l;
        long lag = 0l;
        List<TopicAndPartition> partitions = new ArrayList<TopicAndPartition>();
        for (Entry<Integer,PartitionMetadata> entry : metadatas.entrySet()) 
            int partition = entry.getKey();
            TopicAndPartition testPartition = new TopicAndPartition(topic, partition);
            partitions.add(testPartition);
        
        OffsetFetchRequest fetchRequest = new OffsetFetchRequest(
                group,
                partitions,
                (short) 0,
                correlationId,
                clientId);
        for (Entry<Integer,PartitionMetadata> entry : metadatas.entrySet()) 
            int partition = entry.getKey();
            try 
                channel.send(fetchRequest.underlying());
                OffsetFetchResponse fetchResponse = OffsetFetchResponse.readFrom(channel.receive().payload());
                TopicAndPartition testPartition0 = new TopicAndPartition(topic, partition);
                OffsetMetadataAndError result = fetchResponse.offsets().get(testPartition0);
                short offsetFetchErrorCode = result.error();
                if (offsetFetchErrorCode == ErrorMapping.NotCoordinatorForConsumerCode()) 
                 else 
                    long retrievedOffset = result.offset();
                    sumOffset += retrievedOffset;
                
                String leadBroker = entry.getValue().leader().host();
                String clientName = "Client_" + topic + "_" + partition;
                SimpleConsumer consumer = new SimpleConsumer(leadBroker, port, 100000,
                        64 * 1024, clientName);
                long readOffset = getLastOffset(consumer, topic, partition,
                        kafka.api.OffsetRequest.LatestTime(), clientName);
                sum += readOffset;
                System.out.println(partition+":"+readOffset);
                if(consumer!=null)consumer.close();
             catch (Exception e) 
                channel.disconnect();
            
        

        System.out.println("logSize："+sum);
        System.out.println("offset："+sumOffset);

        lag = sum - sumOffset;
        System.out.println("lag:"+ lag);


    

    public KafkaOffsetTools() 
    


    public static long getLastOffset(SimpleConsumer consumer, String topic,
                                     int partition, long whichTime, String clientName) 
        TopicAndPartition topicAndPartition = new TopicAndPartition(topic,
                partition);
        Map<TopicAndPartition, PartitionOffsetRequestInfo> requestInfo = new HashMap<TopicAndPartition, PartitionOffsetRequestInfo>();
        requestInfo.put(topicAndPartition, new PartitionOffsetRequestInfo(
                whichTime, 1));
        kafka.javaapi.OffsetRequest request = new kafka.javaapi.OffsetRequest(
                requestInfo, kafka.api.OffsetRequest.CurrentVersion(),
                clientName);
        OffsetResponse response = consumer.getOffsetsBefore(request);
        if (response.hasError()) 
            System.out
                    .println("Error fetching data Offset Data the Broker. Reason: "
                            + response.errorCode(topic, partition));
            return 0;
        
        long[] offsets = response.offsets(topic, partition);
        return offsets[0];
    

    private TreeMap<Integer,PartitionMetadata> findLeader(List<String> a_seedBrokers,
                                                          int a_port, String a_topic) 
        TreeMap<Integer, PartitionMetadata> map = new TreeMap<Integer, PartitionMetadata>();
        loop: for (String seed : a_seedBrokers) 
            SimpleConsumer consumer = null;
            try 
                consumer = new SimpleConsumer(seed, a_port, 100000, 64 * 1024,
                        "leaderLookup"+new Date().getTime());
                List<String> topics = Collections.singletonList(a_topic);
                TopicMetadataRequest req = new TopicMetadataRequest(topics);
                kafka.javaapi.TopicMetadataResponse resp = consumer.send(req);

                List<TopicMetadata> metaData = resp.topicsMetadata();
                for (TopicMetadata item : metaData) 
                    for (PartitionMetadata part : item.partitionsMetadata()) 
                        map.put(part.partitionId(), part);
                    
                
             catch (Exception e) 
                System.out.println("Error communicating with Broker [" + seed
                        + "] to find Leader for [" + a_topic + ", ] Reason: " + e);
             finally 
                if (consumer != null)
                    consumer.close();
            
        
        return map;
    

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输出：
logSize：2620569947
offset：2620567473
lag:2474

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参考：kafka