Details
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Sub-task
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Status: Resolved
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Critical
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Resolution: Fixed
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None
Description
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.
Attachments
Issue Links
- is related to
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FLINK-9202 AvroSerializer should not be serializing the target Avro type class
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- Closed
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- relates to
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FLINK-29807 Drop TypeSerializerConfigSnapshot and savepoint support from Flink versions < 1.8.0
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- Closed
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- links to
