向架构注册表发送HTTP请求失败

Question

我正在尝试使用docker compose设置本地kafka connect堆栈，但我的scala producer出现问题，它应该使用schema registry向kafka主题发送avro消息。

在我的生产者（scala）代码中，我执行以下操作：

  val kafkaBootstrapServer = "kafka:9092"
  val schemaRegistryUrl = "http://schema-registry:8081"
  val topicName = "test"

  val props = new Properties()
  props.put("bootstrap.servers", kafkaBootstrapServer)
  props.put("schema.registry.url", schemaRegistryUrl)
  props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer")
  props.put("value.serializer", "io.confluent.kafka.serializers.KafkaAvroSerializer")
  props.put("acks", "1")

我的docker-comment脚本写着：

---
version: '2'
services:
  zookeeper:
    image: confluentinc/cp-zookeeper:5.5.0
    hostname: zookeeper
    container_name: zookeeper
    ports:
      - "2181:2181"
    environment:
      ZOOKEEPER_CLIENT_PORT: 2181
      ZOOKEEPER_TICK_TIME: 2000

  kafka:
    image: confluentinc/cp-kafka:5.5.0
    hostname: kafka
    container_name: kafka
    depends_on:
      - zookeeper
    ports:
      - 9092:9092
    environment:
      KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181
      KAFKA_ADVERTISED_LISTENERS: "PLAINTEXT://kafka:9092"
      KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
      KAFKA_CREATE_TOPICS: "test:1:1"

  schema-registry:
    image: confluentinc/cp-schema-registry:5.5.0
    hostname: schema-registry
    container_name: schema-registry
    depends_on:
      - zookeeper
      - kafka
    ports:
      - "8081:8081"
    environment:
      SCHEMA_REGISTRY_HOST_NAME: schema-registry
      SCHEMA_REGISTRY_KAFKASTORE_CONNECTION_URL: zookeeper:2181

  producer:
   image: producer-app:1.0
   depends_on:
     - schema-registry
     - kafka

编辑：现在架构注册表似乎已启动：

schema-registry    | [2021-01-17 22:27:27,704] INFO HV000001: Hibernate Validator 6.0.17.Final (org.hibernate.validator.internal.util.Version)
kafka              | [2021-01-17 22:27:27,918] INFO [Controller id=1001] Processing automatic preferred replica leader election (kafka.controller.KafkaController)
kafka              | [2021-01-17 22:27:27,919] TRACE [Controller id=1001] Checking need to trigger auto leader balancing (kafka.controller.KafkaController)
kafka              | [2021-01-17 22:27:27,923] DEBUG [Controller id=1001] Topics not in preferred replica for broker 1001 Map() (kafka.controller.KafkaController)
kafka              | [2021-01-17 22:27:27,924] TRACE [Controller id=1001] Leader imbalance ratio for broker 1001 is 0.0 (kafka.controller.KafkaController)
schema-registry    | [2021-01-17 22:27:28,010] INFO JVM Runtime does not support Modules (org.eclipse.jetty.util.TypeUtil)
schema-registry    | [2021-01-17 22:27:28,011] INFO Started o.e.j.s.ServletContextHandler@22d6f11{/,null,AVAILABLE} (org.eclipse.jetty.server.handler.ContextHandler)
schema-registry    | [2021-01-17 22:27:28,035] INFO Started o.e.j.s.ServletContextHandler@15eebbff{/ws,null,AVAILABLE} (org.eclipse.jetty.server.handler.ContextHandler)
schema-registry    | [2021-01-17 22:27:28,058] INFO Started NetworkTrafficServerConnector@2698dc7{HTTP/1.1,[http/1.1]}{0.0.0.0:8081} (org.eclipse.jetty.server.AbstractConnector)
schema-registry    | [2021-01-17 22:27:28,059] INFO Started @4137ms (org.eclipse.jetty.server.Server)
schema-registry    | [2021-01-17 22:27:28,059] INFO Server started, listening for requests... (io.confluent.kafka.schemaregistry.rest.SchemaRegistryMain)

但在此之前，在脚本的执行过程中，我得到：

schema-registry    | ===> Launching ...
schema-registry    | ===> Launching schema-registry ...
producer_1         | [main] ERROR io.confluent.kafka.schemaregistry.client.rest.RestService - Failed to send HTTP request to endpoint: http://schema-registry:8081/subjects/test-value/versions
producer_1         | java.net.ConnectException: Connection refused (Connection refused)

这可能是因为依赖性问题吗？它就像是在完全启动模式注册表之前运行producer！我确实为生产者放置了依赖于-schema注册表。。。




Answer 1

看起来这里的原因是您的应用程序在完成启动之前试图调用架构注册表。也许你的应用程序应该包括一些错误处理这种情况，也许在退避期后重试第一个x故障？