tzulitai commented on a change in pull request #6875: [FLINK-9808] [state backends] Migrate state when necessary in state backends URL: https://github.com/apache/flink/pull/6875#discussion_r226912089
########## File path: flink-state-backends/flink-statebackend-rocksdb/src/main/java/org/apache/flink/contrib/streaming/state/RocksDBKeyedStateBackend.java ########## @@ -1389,6 +1388,149 @@ private void copyStateDataHandleData( return Tuple2.of(stateInfo.f0, newMetaInfo); } + private <N, S extends State, SV> RegisteredKeyValueStateBackendMetaInfo<N, SV> migrateStateIfNecessary( + StateDescriptor<S, SV> stateDesc, + TypeSerializer<N> namespaceSerializer, + Tuple2<ColumnFamilyHandle, RegisteredStateMetaInfoBase> stateInfo, + @Nullable StateSnapshotTransformer<SV> snapshotTransformer) throws Exception { + + StateMetaInfoSnapshot restoredMetaInfoSnapshot = restoredKvStateMetaInfos.get(stateDesc.getName()); + + Preconditions.checkState( + restoredMetaInfoSnapshot != null, + "Requested to check compatibility of a restored RegisteredKeyedBackendStateMetaInfo," + + " but its corresponding restored snapshot cannot be found."); + + Preconditions.checkState(restoredMetaInfoSnapshot.getBackendStateType() + == StateMetaInfoSnapshot.BackendStateType.KEY_VALUE, + "Incompatible state types. " + + "Was [" + restoredMetaInfoSnapshot.getBackendStateType() + "], " + + "registered as [" + StateMetaInfoSnapshot.BackendStateType.KEY_VALUE + "]."); + + Preconditions.checkState( + Objects.equals(stateDesc.getName(), restoredMetaInfoSnapshot.getName()), + "Incompatible state names. " + + "Was [" + restoredMetaInfoSnapshot.getName() + "], " + + "registered with [" + stateDesc.getName() + "]."); + + final StateDescriptor.Type restoredType = + StateDescriptor.Type.valueOf( + restoredMetaInfoSnapshot.getOption( + StateMetaInfoSnapshot.CommonOptionsKeys.KEYED_STATE_TYPE)); + + if (!Objects.equals(stateDesc.getType(), StateDescriptor.Type.UNKNOWN) + && !Objects.equals(restoredType, StateDescriptor.Type.UNKNOWN)) { + + Preconditions.checkState( + stateDesc.getType() == restoredType, + "Incompatible key/value state types. " + + "Was [" + restoredType + "], " + + "registered with [" + stateDesc.getType() + "]."); + } + + TypeSerializer<SV> stateSerializer = stateDesc.getSerializer(); + + RegisteredKeyValueStateBackendMetaInfo<N, SV> newMetaInfo = new RegisteredKeyValueStateBackendMetaInfo<>( + stateDesc.getType(), + stateDesc.getName(), + namespaceSerializer, + stateSerializer, + snapshotTransformer); + + CompatibilityResult<N> namespaceCompatibility = CompatibilityUtil.resolveCompatibilityResult( Review comment: Yes, this indeed is not nice. We actually have a newer replacement class called `TypeSerializerSchemaCompatibility`, but at the moment the use of `CompatibilityResult` can't be completely avoided yet. I have been discussing with @dawidwys that we maybe should just remove `CompatibilityResult` completely in favor of the newer replacement, but this might come up as a separate commit / PR. ---------------------------------------------------------------- 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 With regards, Apache Git Services