apache spark - How to set group.id for consumer group in kafka data source in Structured Streaming?

Question

I want to use Spark Structured Streaming to read from a secure kafka. This means that I will need to force a specific group.id. However, as is stated in the documentation this is not possible. Still, in the databricks documentation https://docs.azuredatabricks.net/spark/latest/structured-streaming/kafka.html#using-ssl, it says that it is possible. Does this only refer to the azure cluster?

Also, by looking at the documentation of the master branch of the apache/spark repo https://github.com/apache/spark/blob/master/docs/structured-streaming-kafka-integration.md, we can understand that such functionality is intended to be added at later spark releases. Do you know of any plans of such a stable release, that is going to allow setting that consumer group.id?

If not, are there any workarounds for Spark 2.4.0 to be able to set a specific consumer group.id?

Answer 1

Currently (v2.4.0) it is not possible.

You can check following lines in Apache Spark project:

https://github.com/apache/spark/blob/v2.4.0/external/kafka-0-10-sql/src/main/scala/org/apache/spark/sql/kafka010/KafkaSourceProvider.scala#L81 - generate group.id

https://github.com/apache/spark/blob/v2.4.0/external/kafka-0-10-sql/src/main/scala/org/apache/spark/sql/kafka010/KafkaSourceProvider.scala#L534 - set it in properties, that are used to create KafkaConsumer

In master branch you can find modification, that enable to setting prefix or particular group.id

https://github.com/apache/spark/blob/master/external/kafka-0-10-sql/src/main/scala/org/apache/spark/sql/kafka010/KafkaSourceProvider.scala#L83 - generate group.id based on group prefix (groupidprefix)

https://github.com/apache/spark/blob/master/external/kafka-0-10-sql/src/main/scala/org/apache/spark/sql/kafka010/KafkaSourceProvider.scala#L543 - set previously generated groupId, if kafka.group.id wasn't passed in properties