Tzu-Li (Gordon) Tai created FLINK-8421:
------------------------------------------
Summary: HeapInternalTimerService should reconfigure compatible key / namespace serializers on restore
Key: FLINK-8421
URL:
https://issues.apache.org/jira/browse/FLINK-8421 Project: Flink
Issue Type: Bug
Affects Versions: 1.4.0, 1.5.0
Reporter: Tzu-Li (Gordon) Tai
Priority: Blocker
Fix For: 1.3.3, 1.5.0, 1.4.1
The {{HeapInternalTimerService}} still uses simple {{equals}} checks on restored / newly provided serializers for compatibility checks. This should be replaced with the {{TypeSerializer::ensureCompatibility}} checks instead, so that new serializers can be reconfigured.
For Flink 1.4.0 release and current master, this is a critical bug since the {{KryoSerializer}} has different default base registrations than before due to FLINK-7420. i.e if the key of a window is serialized using the {{KryoSerializer}} in 1.3.x, the restore would never succeed in 1.4.0.
For 1.3.x, this fix would be an improvement, such that the {{HeapInternalTimerService}} restore will make use of serializer reconfiguration.
Other remarks:
* We need to double check all operators that checkpoint / restore from **raw** state. Apparently, the serializer compatibility checks were only implemented for managed state.
* Migration ITCases apparently do not have enough coverage. A migration test job that uses a key type which required the {{KryoSerializer}}, and uses windows, would have caught this issue.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
Locked
