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Chris Egerton commented on KAFKA-12487: --------------------------------------- Based on recent [KIP-726|https://lists.apache.org/thread.html/%3CCAFLS_9gOHobj-had=7SVBibJTxfzKCuf7WM+shTL_aTvSeyq=g...@mail.gmail.com%3E] discussion, we'll also want to implement the [Consumer::onPartitionsLost|https://kafka.apache.org/27/javadoc/org/apache/kafka/clients/consumer/ConsumerRebalanceListener.html#onPartitionsLost-java.util.Collection-] method in order to avoid task failures due to offset commit failures if/when the consumer rebalance protocol is automatically downgraded from {{COOPERATIVE}} to {{EAGER}}. > Sink connectors do not work with the cooperative consumer rebalance protocol > ---------------------------------------------------------------------------- > > Key: KAFKA-12487 > URL: https://issues.apache.org/jira/browse/KAFKA-12487 > Project: Kafka > Issue Type: Bug > Components: KafkaConnect > Affects Versions: 3.0.0, 2.4.2, 2.5.2, 2.8.0, 2.7.1, 2.6.2 > Reporter: Chris Egerton > Assignee: Chris Egerton > Priority: Major > > The {{ConsumerRebalanceListener}} used by the framework to respond to > rebalance events in consumer groups for sink tasks is hard-coded with the > assumption that the consumer performs rebalances eagerly. In other words, it > assumes that whenever {{onPartitionsRevoked}} is called, all partitions have > been revoked from that consumer, and whenever {{onPartitionsAssigned}} is > called, the partitions passed in to that method comprise the complete set of > topic partitions assigned to that consumer. > See the [WorkerSinkTask.HandleRebalance > class|https://github.com/apache/kafka/blob/b96fc7892f1e885239d3290cf509e1d1bb41e7db/connect/runtime/src/main/java/org/apache/kafka/connect/runtime/WorkerSinkTask.java#L669-L730] > for the specifics. > > One issue this can cause is silently ignoring to-be-committed offsets > provided by sink tasks, since the framework ignores offsets provided by tasks > in their {{preCommit}} method if it does not believe that the consumer for > that task is currently assigned the topic partition for that offset. See > these lines in the [WorkerSinkTask::commitOffsets > method|https://github.com/apache/kafka/blob/b96fc7892f1e885239d3290cf509e1d1bb41e7db/connect/runtime/src/main/java/org/apache/kafka/connect/runtime/WorkerSinkTask.java#L429-L430] > for reference. > > This may not be the only issue caused by configuring a sink connector's > consumer to use cooperative rebalancing. Rigorous unit and integration > testing should be added before claiming that the Connect framework supports > the use of cooperative consumers with sink connectors. -- This message was sent by Atlassian Jira (v8.3.4#803005)