Confluent Local服务启动失败：Schema Registry无法启动求助

问题描述 #

执行confluent local services start命令时，ZooKeeper与Kafka均成功启动，但Schema Registry启动失败。已尝试销毁并重启服务，问题仍未解决。

环境信息 #

• JAVA_HOME: JAVA_HOME is /usr/local/opt/openjdk@11
• Confluent版本：7.3.2
• 环境变量配置：

  export CONFLUENT_HOME=/Users/adminuser/confluent-7.3.2
  export PATH="${CONFLUENT_HOME}/bin:$PATH"
  

启动命令执行日志 #

~ » confluent local services start                                                                                                                                                                          ramana@mbp
The local commands are intended for a single-node development environment only,
NOT for production usage. https://docs.confluent.io/current/cli/index.html

Using CONFLUENT_CURRENT: /var/folders/k8/sd8b8dnn5n956nbdy4npjcyw0000gn/T/confluent.019095
Starting ZooKeeper
ZooKeeper is [UP]
Starting Kafka
Kafka is [UP]
Starting Schema Registry
Error: Schema Registry failed to start

Schema Registry报错日志 #

[2023-03-18 19:45:47,156] ERROR [kafka-store-reader-thread-_schemas]: Error due to (io.confluent.kafka.schemaregistry.storage.KafkaStoreReaderThread:76)
java.lang.RuntimeException: org.apache.kafka.common.protocol.types.SchemaException: Buffer underflow while parsing response for request with header RequestHeader(apiKey=FETCH, apiVersion=13, clientId=KafkaStore-reader-_schemas, correlationId=9)
    at io.confluent.kafka.schemaregistry.storage.KafkaStoreReaderThread.doWork(KafkaStoreReaderThread.java:302)
    at kafka.utils.ShutdownableThread.run(ShutdownableThread.scala:99)
Caused by: org.apache.kafka.common.protocol.types.SchemaException: Buffer underflow while parsing response for request with header RequestHeader(apiKey=FETCH, apiVersion=13, clientId=KafkaStore-reader-_schemas, correlationId=9)
    at org.apache.kafka.clients.NetworkClient.parseResponse(NetworkClient.java:826)
    at org.apache.kafka.clients.NetworkClient.handleCompletedReceives(NetworkClient.java:970)
    at org.apache.kafka.clients.NetworkClient.poll(NetworkClient.java:652)
    at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:280)
    at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:251)
    at org.apache.kafka.clients.consumer.KafkaConsumer.pollForFetches(KafkaConsumer.java:1311)
    at org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:1247)
    at org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:1173)
    at io.confluent.kafka.schemaregistry.storage.KafkaStoreReaderThread.doWork(KafkaStoreReaderThread.java:197)
    ... 1 more
Caused by: java.nio.BufferUnderflowException
    at java.base/java.nio.Buffer.nextGetIndex(Buffer.java:651)
    at java.base/java.nio.HeapByteBuffer.getInt(HeapByteBuffer.java:402)
    at org.apache.kafka.common.protocol.ByteBufferAccessor.readInt(ByteBufferAccessor.java:43)
    at org.apache.kafka.common.message.ResponseHeaderData.read(ResponseHeaderData.java:95)
    at org.apache.kafka.common.message.ResponseHeaderData.<init>(ResponseHeaderData.java:67)
    at org.apache.kafka.common.requests.ResponseHeader.parse(ResponseHeader.java:71)
    at org.apache.kafka.common.requests.AbstractResponse.parseResponse(AbstractResponse.java:109)
    at org.apache.kafka.clients.NetworkClient$DefaultClientInterceptor.parseResponse(NetworkClient.java:1531)
    at org.apache.kafka.clients.NetworkClient.parseResponse(NetworkClient.java:819)
    ... 9 more
[2023-03-18 19:45:47,156] INFO [kafka-store-reader-thread-_schemas]: Stopped (io.confluent.kafka.schemaregistry.storage.KafkaStoreReaderThread:66)
[2023-03-18 19:46:46,095] ERROR Error starting the schema registry (io.confluent.kafka.schemaregistry.rest.SchemaRegistryRestApplication:77)
io.confluent.kafka.schemaregistry.exceptions.SchemaRegistryInitializationException: io.confluent.kafka.schemaregistry.exceptions.SchemaRegistryTimeoutException: Timed out waiting for join group to complete
    at io.confluent.kafka.schemaregistry.storage.KafkaSchemaRegistry.init(KafkaSchemaRegistry.java:334)
    at io.confluent.kafka.schemaregistry.rest.SchemaRegistryRestApplication.initSchemaRegistry(SchemaRegistryRestApplication.java:75)
    at io.confluent.kafka.schemaregistry.rest.SchemaRegistryRestApplication.configureBaseApplication(SchemaRegistryRestApplication.java:90)
    at io.confluent.rest.Application.configureHandler(Application.java:285)
    at io.confluent.rest.ApplicationServer.doStart(ApplicationServer.java:270)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:73)
    at io.confluent.kafka.schemaregistry.rest.SchemaRegistryMain.main(SchemaRegistryMain.java:44)
Caused by: io.confluent.kafka.schemaregistry.exceptions.SchemaRegistryTimeoutException: Timed out waiting for join group to complete
    at io.confluent.kafka.schemaregistry.leaderelector.kafka.KafkaGroupLeaderElector.init(KafkaGroupLeaderElector.java:211)
    at io.confluent.kafka.schemaregistry.storage.KafkaSchemaRegistry.init(KafkaSchemaRegistry.java:329)
    ... 6 more

解决方法 #

1. 检查Kafka Listener配置 #

Schema Registry需要正常连接Kafka，确保Kafka的listener配置正确。修改${CONFLUENT_HOME}/etc/kafka/server.properties：

listeners=PLAINTEXT://localhost:9092
advertised.listeners=PLAINTEXT://localhost:9092

然后重启服务：

confluent local services kafka restart
confluent local services schema-registry start

2. 调整Schema Registry超时时间 #

针对日志中的Timed out waiting for join group to complete错误，修改${CONFLUENT_HOME}/etc/schema-registry/schema-registry.properties：

schema.registry.group.init.timeout.ms=30000

重启Schema Registry生效。

3. 清理损坏的Kafka数据 #

如果_schemas主题存在损坏数据，会导致Schema Registry无法读取。执行以下操作：

confluent local services stop
confluent local destroy
confluent local services start

4. 确认Java版本兼容性 #

Confluent 7.3.2支持Java 11/17，执行java -version确认当前使用的是OpenJDK 11，确保JAVA_HOME指向正确路径且无其他Java版本干扰。

内容的提问来源于stack exchange，提问作者Raman