Ufuk Celebi created FLINK-5601:
----------------------------------
Summary: Window operator does not checkpoint watermarks
Key: FLINK-5601
URL:
https://issues.apache.org/jira/browse/FLINK-5601 Project: Flink
Issue Type: Improvement
Components: State Backends, Checkpointing
Reporter: Ufuk Celebi
During release testing [~
[hidden email]] and I noticed that watermarks are not checkpointed in the window operator.
This can lead to non determinism when restoring checkpoints. I was running an adjusted {{SessionWindowITCase}} via Kafka for testing migration and rescaling and ran into failures, because the data generator required determinisitic behaviour.
What happened was that on restore it could happen that late elements were not dropped, because the watermarks needed to be re-established after restore first.
[~aljoscha] Do you know whether there is a special reason for explicitly not checkpointing watermarks?
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
Locked
