kafka config_error ai_generated true

org.apache.kafka.connect.errors.ConnectException: Worker config must have exactly one of 'key.converter' or 'value.converter' set, but found 0

ID: kafka/connect-worker-config-mismatch

Also available as: JSON · Markdown · 中文
95%Fix Rate
89%Confidence
1Evidence
2024-06-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
Kafka 3.6.0 active — — —
Kafka 3.7.0 active — — —
Kafka Connect 3.6.0 active — — —

Root Cause

Kafka Connect worker is missing required converter configuration for key or value serialization, causing startup failure.

generic

中文

Kafka Connect工作器缺少键或值序列化所需的转换器配置，导致启动失败。

Official Documentation

https://kafka.apache.org/documentation/#connect_configuring

Workarounds

  1. 95% success Add `key.converter=org.apache.kafka.connect.json.JsonConverter` and `value.converter=org.apache.kafka.connect.json.JsonConverter` in worker.properties, then restart the worker. 
    Add `key.converter=org.apache.kafka.connect.json.JsonConverter` and `value.converter=org.apache.kafka.connect.json.JsonConverter` in worker.properties, then restart the worker.
  2. 90% success Example fix in worker.properties: `key.converter=org.apache.kafka.connect.storage.StringConverter` and `value.converter=org.apache.kafka.connect.json.JsonConverter` for mixed formats. 
    Example fix in worker.properties: `key.converter=org.apache.kafka.connect.storage.StringConverter` and `value.converter=org.apache.kafka.connect.json.JsonConverter` for mixed formats.
  3. 85% success Check environment variable overrides: `echo $CONNECT_KEY_CONVERTER` and ensure they are not conflicting. 
    Check environment variable overrides: `echo $CONNECT_KEY_CONVERTER` and ensure they are not conflicting.

中文步骤

  1. Add `key.converter=org.apache.kafka.connect.json.JsonConverter` and `value.converter=org.apache.kafka.connect.json.JsonConverter` in worker.properties, then restart the worker.
  2. Example fix in worker.properties: `key.converter=org.apache.kafka.connect.storage.StringConverter` and `value.converter=org.apache.kafka.connect.json.JsonConverter` for mixed formats.
  3. Check environment variable overrides: `echo $CONNECT_KEY_CONVERTER` and ensure they are not conflicting.

Dead Ends

Common approaches that don't work:

  1. 70% fail

    The error says exactly one must be set; setting both does not fix the missing configuration.

  2. 80% fail

    Defaults are not guaranteed and may not match the connector's data format.