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ASF GitHub Bot commented on FLINK-8421: --------------------------------------- Github user tzulitai commented on the issue: https://github.com/apache/flink/pull/5362 Thanks for the reviews! Will merge after Travis gives green. > 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 > Assignee: 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. > This would entail that the {{TypeSerializerConfiguration}} of the key and > namespace serializer in the {{HeapInternalTimerService}} also needs to be > written to the raw state. > 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 (v7.6.3#76005)