Kafka Java-Consumer funktioniert nur für localhost und schlägt für Remote-Server fehl

Question

Ich arbeite seit zwei Monaten mit Kafka und habe diesen Code verwendet, um Nachrichten lokal zu konsumieren. Ich habe vor kurzem beschlossen, Zookeeper und Kafka zu verteilen und alles scheint gut zu funktionieren. Mein Problem begann, als ich versuchte, den Code des Kunden von einer Remote-IP zu verwenden. Sobald ich seeds.add("127.0.0.1");-seeds.add("104.131.40.xxx"); ändern erhalte ich diese Fehlermeldung:

run: 
Error communicating with Broker [104.131.40.xxx] to find Leader for [temperature, 0] Reason: 
java.net.ConnectException: Connection refused Can't find metadata for Topic and Partition. Exiting 
BUILD SUCCESSFUL (total time: 21 seconds)r code here 

dies den Code ist, dass ich derzeit verwenden:

/* 
Kafka API consumer reads 10 readings from the "temperature" topic 
*/ 

package simpleexample; 

import kafka.api.FetchRequest; 
import kafka.api.FetchRequestBuilder; 
import kafka.api.PartitionOffsetRequestInfo; 
import kafka.common.ErrorMapping; 
import kafka.common.TopicAndPartition; 
import kafka.javaapi.*; 
import kafka.javaapi.consumer.SimpleConsumer; 
import kafka.message.MessageAndOffset; 

import java.nio.ByteBuffer; 
import java.util.ArrayList; 
import java.util.Collections; 
import java.util.HashMap; 
import java.util.List; 
import java.util.Map; 

public class SimpleExample { 
public static void main(String args[]) { 
    SimpleExample example = new SimpleExample(); 
    //long maxReads = Long.parseLong(args[0]); 
    long maxReads = 10; 
    //String topic = args[1]; 
    String topic = "temperature"; 
    //int partition = Integer.parseInt(args[2]); 
    int partition =0; 
    List<String> seeds = new ArrayList<String>(); 
    //seeds.add(args[3]); 
    seeds.add("104.131.40.xxx"); 
    //int port = Integer.parseInt(args[4]); 
    int port =9092; 
    try { 
     example.run(maxReads, topic, partition, seeds, port); 
    } catch (Exception e) { 
     System.out.println("Oops:" + e); 
     e.printStackTrace(); 
    } 
} 

private List<String> m_replicaBrokers = new ArrayList<String>(); 

public SimpleExample() { 
    m_replicaBrokers = new ArrayList<String>(); 
} 

public void run(long a_maxReads, String a_topic, int a_partition, List<String> a_seedBrokers, int a_port) throws Exception { 
    // find the meta data about the topic and partition we are interested in 
    // 
    PartitionMetadata metadata = findLeader(a_seedBrokers, a_port, a_topic, a_partition); 
    if (metadata == null) { 
     System.out.println("Can't find metadata for Topic and Partition. Exiting"); 
     return; 
    } 
    if (metadata.leader() == null) { 
     System.out.println("Can't find Leader for Topic and Partition. Exiting"); 
     return; 
    } 
    String leadBroker = metadata.leader().host(); 
    String clientName = "Client_" + a_topic + "_" + a_partition; 

    SimpleConsumer consumer = new SimpleConsumer(leadBroker, a_port, 100000, 64 * 1024, clientName); 
    long readOffset = getLastOffset(consumer,a_topic, a_partition, kafka.api.OffsetRequest.EarliestTime(), clientName); 

    int numErrors = 0; 
    while (a_maxReads > 0) { 
     if (consumer == null) { 
      consumer = new SimpleConsumer(leadBroker, a_port, 100000, 64 * 1024, clientName); 
     } 
     FetchRequest req = new FetchRequestBuilder() 
       .clientId(clientName) 
       .addFetch(a_topic, a_partition, readOffset, 100000) // Note: this fetchSize of 100000 might need to be increased if large batches are written to Kafka 
       .build(); 
     FetchResponse fetchResponse = consumer.fetch(req); 

     if (fetchResponse.hasError()) { 
      numErrors++; 
      // Something went wrong! 
      short code = fetchResponse.errorCode(a_topic, a_partition); 
      System.out.println("Error fetching data from the Broker:" + leadBroker + " Reason: " + code); 
      if (numErrors > 5) break; 
      if (code == ErrorMapping.OffsetOutOfRangeCode()) { 
       // We asked for an invalid offset. For simple case ask for the last element to reset 
       readOffset = getLastOffset(consumer,a_topic, a_partition, kafka.api.OffsetRequest.LatestTime(), clientName); 
       continue; 
      } 
      consumer.close(); 
      consumer = null; 
      leadBroker = findNewLeader(leadBroker, a_topic, a_partition, a_port); 
      continue; 
     } 
     numErrors = 0; 

     long numRead = 0; 
     for (MessageAndOffset messageAndOffset : fetchResponse.messageSet(a_topic, a_partition)) { 
      long currentOffset = messageAndOffset.offset(); 
      if (currentOffset < readOffset) { 
       System.out.println("Found an old offset: " + currentOffset + " Expecting: " + readOffset); 
       continue; 
      } 
      readOffset = messageAndOffset.nextOffset(); 
      ByteBuffer payload = messageAndOffset.message().payload(); 

      byte[] bytes = new byte[payload.limit()]; 
      payload.get(bytes); 
      System.out.println(String.valueOf(messageAndOffset.offset()) + ": " + new String(bytes, "UTF-8")); 
      numRead++; 
      a_maxReads--; 
     } 

     if (numRead == 0) { 
      try { 
       Thread.sleep(1000); 
      } catch (InterruptedException ie) { 
      } 
     } 
    } 
    if (consumer != null) consumer.close(); 
} 

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 String findNewLeader(String a_oldLeader, String a_topic, int a_partition, int a_port) throws Exception { 
    for (int i = 0; i < 3; i++) { 
     boolean goToSleep = false; 
     PartitionMetadata metadata = findLeader(m_replicaBrokers, a_port, a_topic, a_partition); 
     if (metadata == null) { 
      goToSleep = true; 
     } else if (metadata.leader() == null) { 
      goToSleep = true; 
     } else if (a_oldLeader.equalsIgnoreCase(metadata.leader().host()) && i == 0) { 
      // first time through if the leader hasn't changed give ZooKeeper a second to recover 
      // second time, assume the broker did recover before failover, or it was a non-Broker issue 
      // 
      goToSleep = true; 
     } else { 
      return metadata.leader().host(); 
     } 
     if (goToSleep) { 
      try { 
       Thread.sleep(1000); 
      } catch (InterruptedException ie) { 
      } 
     } 
    } 
    System.out.println("Unable to find new leader after Broker failure. Exiting"); 
    throw new Exception("Unable to find new leader after Broker failure. Exiting"); 
} 

private PartitionMetadata findLeader(List<String> a_seedBrokers, int a_port, String a_topic, int a_partition) { 
    PartitionMetadata returnMetaData = null; 
    loop: 
    for (String seed : a_seedBrokers) { 
     SimpleConsumer consumer = null; 
     try { 
      consumer = new SimpleConsumer(seed, a_port, 100000, 64 * 1024, "leaderLookup"); 
      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()) { 
        if (part.partitionId() == a_partition) { 
         returnMetaData = part; 
         break loop; 
        } 
       } 
      } 
     } catch (Exception e) { 
      System.out.println("Error communicating with Broker [" + seed + "] to find Leader for [" + a_topic 
        + ", " + a_partition + "] Reason: " + e); 
     } finally { 
      if (consumer != null) consumer.close(); 
     } 
    } 
    if (returnMetaData != null) { 
     m_replicaBrokers.clear(); 
     for (kafka.cluster.Broker replica : returnMetaData.replicas()) { 
      m_replicaBrokers.add(replica.host()); 
     } 
    } 
    return returnMetaData; 
} 
} 

Answer 1

Sie müssen die advertised.host.name einstellen statt host.name in der kafka server.properties Konfigurationsdatei.