Kafka error: SLF4J: Failed toString() invocation on an object of type [org.apache.kafka.common.Cluster]

问题

I am trying to use Gatling with Kafka, but every so often get this error:

01:32:53.933 [kafka-producer-network-thread | producer-1] DEBUG o.apache.kafka.clients.NetworkClient - Sending metadata request ClientRequest(expectResponse=true, payload=null, request=RequestSend(header={api_key=3,api_version=0,correlation_id=12,client_id=producer-1}, body={topics=[test]})) to node 1011
SLF4J: Failed toString() invocation on an object of type [org.apache.kafka.common.Cluster]
java.lang.NullPointerException
at org.apache.kafka.common.PartitionInfo.toString(PartitionInfo.java:72)
    at java.lang.String.valueOf(String.java:2994)
    at java.lang.StringBuilder.append(StringBuilder.java:131)
    at java.util.AbstractCollection.toString(AbstractCollection.java:462)
    at java.lang.String.valueOf(String.java:2994)
    at java.lang.StringBuilder.append(StringBuilder.java:131)
    at org.apache.kafka.common.Cluster.toString(Cluster.java:151)
    at org.slf4j.helpers.MessageFormatter.safeObjectAppend(MessageFormatter.java:305)
    at org.slf4j.helpers.MessageFormatter.deeplyAppendParameter(MessageFormatter.java:277)
    at org.slf4j.helpers.MessageFormatter.arrayFormat(MessageFormatter.java:231)
    at ch.qos.logback.classic.spi.LoggingEvent.getFormattedMessage(LoggingEvent.java:298)
    at ch.qos.logback.classic.spi.LoggingEvent.prepareForDeferredProcessing(LoggingEvent.java:208)
    at ch.qos.logback.core.OutputStreamAppender.subAppend(OutputStreamAppender.java:212)
    at ch.qos.logback.core.OutputStreamAppender.append(OutputStreamAppender.java:103)
    at ch.qos.logback.core.UnsynchronizedAppenderBase.doAppend(UnsynchronizedAppenderBase.java:88)
    at ch.qos.logback.core.spi.AppenderAttachableImpl.appendLoopOnAppenders(AppenderAttachableImpl.java:48)
    at ch.qos.logback.classic.Logger.appendLoopOnAppenders(Logger.java:273)
    at ch.qos.logback.classic.Logger.callAppenders(Logger.java:260)
    at ch.qos.logback.classic.Logger.buildLoggingEventAndAppend(Logger.java:442)
    at ch.qos.logback.classic.Logger.filterAndLog_2(Logger.java:433)
    at ch.qos.logback.classic.Logger.debug(Logger.java:511)
    at org.apache.kafka.clients.producer.internals.Metadata.update(Metadata.java:133)
    at org.apache.kafka.clients.NetworkClient.handleMetadataResponse(NetworkClient.java:313)
    at org.apache.kafka.clients.NetworkClient.handleCompletedReceives(NetworkClient.java:298)
    at org.apache.kafka.clients.NetworkClient.poll(NetworkClient.java:199)
    at org.apache.kafka.clients.producer.internals.Sender.run(Sender.java:191)
    at org.apache.kafka.clients.producer.internals.Sender.run(Sender.java:122)
    at java.lang.Thread.run(Thread.java:745)
01:32:53.937 [kafka-producer-network-thread | producer-1] DEBUG o.a.k.c.producer.internals.Metadata - Updated cluster metadata version 14 to [FAILED toString()]

I'm not sure if the error is related to the code, but here is my BasicSimulation.scala:

class BasicSimulation extends Simulation {

val kafkaConf = kafka
    .topic("test")
    .properties(
      Map(
        ProducerConfig.ACKS_CONFIG -> "1",
        ProducerConfig.BOOTSTRAP_SERVERS_CONFIG -> "kafka:9092",
        ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG ->
          "org.apache.kafka.common.serialization.ByteArraySerializer",
        ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG ->
          "org.apache.kafka.common.serialization.ByteArraySerializer"))

  val scn = scenario("Kafka Test")
    .feed(csv("data.csv").circular)
    .exec(kafka("request")
    .send("${data}".getBytes: Array[Byte]))

  setUp(
    scn
      .inject(constantUsersPerSec(10) during(10 seconds)))
    .protocols(kafkaConf)
}

Here is the kafka-related segment of my docker-compose.yml:

zookeeper:
    image: wurstmeister/zookeeper
    ports:
      - "2181:2181"

  kafka:
    image: wurstmeister/kafka
    ports:
      - "9092:9092"
    depends_on:
      - zookeeper
    environment:
      KAFKA_ADVERTISED_HOST_NAME: kafka
      KAFKA_ADVERTISED_PORT: 9092
      KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181
      KAFKA_CREATE_TOPICS: "test:1:1"
      KAFKA_LOG_CLEANER_ENABLE: 'true'
    volumes:
      - /tmp/docker.sock:/var/run/docker.sock

回答1:

It is Kafka dependecy version issue. Installed Kafka version and Kafka-client dependency version is mismateched. First validate installed Kafaka version and update Kafka-client version in POM accordingy. I faced same issue and resolved by correcting kafka-client version.

Installed KAFKA version: 0.11

Maven Dependency:
        <dependency>
            <groupId>org.apache.kafka</groupId>
            <artifactId>kafka-clients</artifactId>
            <version>0.11.0.0</version>
        </dependency>

Now it's working fine for me.

回答2:

In my case it was a version issue. I was using incompatible kafka build and kafka clients library.

When I switched to kafka_2.11-0.10.2.1 and kafka-clients 0.10.2.0, the issue was resolved.

回答3:

Stopping and removing my docker containers seems to have fixed it.

docker stop $(docker ps -a -q)
docker rm $(docker ps -a -q)

来源：https://stackoverflow.com/questions/41794651/kafka-error-slf4j-failed-tostring-invocation-on-an-object-of-type-org-apach