java - Kafka 消费者协调器连接问题，Kafka 0.11.0.3

Question

我似乎无法让我的 Java Kafka 客户端工作。症状:

在日志中看到“发现协调器”，然后不到一秒后，看到“将协调器标记为死亡”。此后不再出现任何输出。

调试代码显示org.apache.kafka.clients.consumer.KafkaConsumer.poll()永远不会返回。代码卡在 ConsumerNetworkClient 类中的 do-while 循环中:

public boolean awaitMetadataUpdate(long timeout) {
    long startMs = this.time.milliseconds();
    int version = this.metadata.requestUpdate();

    do {
        this.poll(timeout);
    } while(this.metadata.version() == version && this.time.milliseconds() - startMs < timeout);

    return this.metadata.version() > version;
}

日志显示:

2019-09-25 15:25:45.268 [main]  INFO    org.apache.kafka.clients.consumer.ConsumerConfig    ConsumerConfig values: 
    auto.commit.interval.ms = 5000
    auto.offset.reset = latest
    bootstrap.servers = [localhost:9092]
    check.crcs = true
    client.id = 
    connections.max.idle.ms = 540000
    enable.auto.commit = true
    exclude.internal.topics = true
    fetch.max.bytes = 52428800
    fetch.max.wait.ms = 500
    fetch.min.bytes = 1
    group.id = foo
    heartbeat.interval.ms = 3000
    interceptor.classes = null
    internal.leave.group.on.close = true
    isolation.level = read_uncommitted
    key.deserializer = class org.apache.kafka.common.serialization.StringDeserializer
    max.partition.fetch.bytes = 1048576
    max.poll.interval.ms = 300000
    max.poll.records = 500
    metadata.max.age.ms = 300000
    metric.reporters = []
    metrics.num.samples = 2
    metrics.recording.level = INFO
    metrics.sample.window.ms = 30000
    partition.assignment.strategy = [class org.apache.kafka.clients.consumer.RangeAssignor]
    receive.buffer.bytes = 65536
    reconnect.backoff.max.ms = 1000
    reconnect.backoff.ms = 50
    request.timeout.ms = 305000
    retry.backoff.ms = 100
    sasl.jaas.config = null
    sasl.kerberos.kinit.cmd = /usr/bin/kinit
    sasl.kerberos.min.time.before.relogin = 60000
    sasl.kerberos.service.name = null
    sasl.kerberos.ticket.renew.jitter = 0.05
    sasl.kerberos.ticket.renew.window.factor = 0.8
    sasl.mechanism = GSSAPI
    security.protocol = PLAINTEXT
    send.buffer.bytes = 131072
    session.timeout.ms = 10000
    ssl.cipher.suites = null
    ssl.enabled.protocols = [TLSv1.2, TLSv1.1, TLSv1]
    ssl.endpoint.identification.algorithm = null
    ssl.key.password = null
    ssl.keymanager.algorithm = SunX509
    ssl.keystore.location = null
    ssl.keystore.password = null
    ssl.keystore.type = JKS
    ssl.protocol = TLS
    ssl.provider = null
    ssl.secure.random.implementation = null
    ssl.trustmanager.algorithm = PKIX
    ssl.truststore.location = null
    ssl.truststore.password = null
    ssl.truststore.type = JKS
    value.deserializer = class com.mycompany.KafkaMessageJsonNodeDeserializer

2019-09-25 15:25:45.312 [main]  INFO    org.apache.kafka.common.utils.AppInfoParser -   Kafka version : 0.11.0.3
2019-09-25 15:25:45.312 [main]  INFO    org.apache.kafka.common.utils.AppInfoParser -   Kafka commitId : 26ddb9e3197be39a
2019-09-25 15:25:47.700 [pool-2-thread-1]   INFO    org.apache.kafka.clients.consumer.internals.AbstractCoordinator -   Discovered coordinator ad0c03f60f39:9092 (id: 2147483647 rack: null) for group foo.
2019-09-25 15:25:47.705 [pool-2-thread-1]   INFO    org.apache.kafka.clients.consumer.internals.AbstractCoordinator -   Marking the coordinator ad0c03f60f39:9092 (id: 2147483647 rack: null) dead for group foo

..如果打开了调试，那么日志也会有如下消息:

Coordinator discovery failed for group foo, refreshing metadata

更多详细信息:

我在 docker 容器内运行 kafka。在 docker 容器内运行控制台使用者时，一切都很好。控制台消费者可以很好地接收消息。我的应用程序(出现问题的地方)在 docker 容器外部运行。

docker run 命令包含 -p 2181:2181 -p 9001:9001 -p 9092:9092。

当 Kafka 客户端陷入循环时，堆栈看起来像这样:

awaitMetadataUpdate:134, ConsumerNetworkClient (org.apache.kafka.clients.consumer.internals)
ensureCoordinatorReady:226, AbstractCoordinator (org.apache.kafka.clients.consumer.internals)
ensureCoordinatorReady:203, AbstractCoordinator (org.apache.kafka.clients.consumer.internals)
poll:286, ConsumerCoordinator (org.apache.kafka.clients.consumer.internals)
pollOnce:1078, KafkaConsumer (org.apache.kafka.clients.consumer)
poll:1043, KafkaConsumer (org.apache.kafka.clients.consumer)

Answer 1

看起来，您的经纪商正在将自己广告为 ad0c03f60f39。而且您似乎正在从主机运行客户端，由于显而易见的原因，该客户端无法解析 ad0c03f60f39 。您需要配置代理以将其自身广告为可从主机解析的内容。在 server.properties 中查找“advertished.listeners”，您可以设置类似 PLAINTEXT://localhost:9092