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ASF GitHub Bot commented on FLINK-9377: --------------------------------------- StephanEwen commented on a change in pull request #6711: [FLINK-9377] [core, state backends] Remove serializers from checkpoints URL: https://github.com/apache/flink/pull/6711#discussion_r220739021 ########## File path: flink-core/src/main/java/org/apache/flink/core/io/VersionedIOReadableWritable.java ########## @@ -77,6 +77,11 @@ private void resolveVersionRead(int readVersion) throws VersionMismatchException } } + // TODO this is a temporary workaround for FLINK-9377 that should be removed + if (readVersion == getVersion() + 1) { Review comment: This seems fragile here, because it is in a common base class outside the serializer utils. Can this be solved by overriding "getCompatibleVersions()" instead? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org > Remove writing serializers as part of the checkpoint meta information > --------------------------------------------------------------------- > > Key: FLINK-9377 > URL: https://issues.apache.org/jira/browse/FLINK-9377 > Project: Flink > Issue Type: Sub-task > Components: State Backends, Checkpointing > Reporter: Tzu-Li (Gordon) Tai > Assignee: Tzu-Li (Gordon) Tai > Priority: Critical > Labels: pull-request-available > Fix For: 1.7.0 > > > When writing meta information of a state in savepoints, we currently write > both the state serializer as well as the state serializer's configuration > snapshot. > Writing both is actually redundant, as most of the time they have identical > information. > Moreover, the fact that we use Java serialization to write the serializer > and rely on it to be re-readable on the restore run, already poses problems > for serializers such as the {{AvroSerializer}} (see discussion in FLINK-9202) > to perform even a compatible upgrade. > The proposal here is to leave only the config snapshot as meta information, > and use that as the single source of truth of information about the schema of > serialized state. > The config snapshot should be treated as a factory (or provided to a > factory) to re-create serializers capable of reading old, serialized state. -- This message was sent by Atlassian JIRA (v7.6.3#76005)