StefanRRichter 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_r227761120
########## File path: flink-runtime/src/test/java/org/apache/flink/runtime/state/StateBackendMigrationTestBase.java ########## @@ -0,0 +1,780 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.flink.runtime.state; + +import org.apache.flink.api.common.JobID; +import org.apache.flink.api.common.state.ValueState; +import org.apache.flink.api.common.state.ValueStateDescriptor; +import org.apache.flink.api.common.typeutils.TypeSerializer; +import org.apache.flink.api.common.typeutils.TypeSerializerSchemaCompatibility; +import org.apache.flink.api.common.typeutils.TypeSerializerSnapshot; +import org.apache.flink.api.common.typeutils.base.IntSerializer; +import org.apache.flink.core.memory.DataInputView; +import org.apache.flink.core.memory.DataOutputView; +import org.apache.flink.runtime.checkpoint.CheckpointOptions; +import org.apache.flink.runtime.checkpoint.StateObjectCollection; +import org.apache.flink.runtime.execution.Environment; +import org.apache.flink.runtime.operators.testutils.DummyEnvironment; +import org.apache.flink.types.StringValue; +import org.apache.flink.util.TestLogger; +import org.junit.Rule; +import org.junit.Test; +import org.junit.rules.ExpectedException; + +import java.io.IOException; +import java.util.Collections; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.concurrent.RunnableFuture; + +import static org.junit.Assert.assertEquals; + +/** + * Tests for the {@link KeyedStateBackend} and {@link OperatorStateBackend} as produced + * by various {@link StateBackend}s. + */ +@SuppressWarnings("serial") +public abstract class StateBackendMigrationTestBase<B extends AbstractStateBackend> extends TestLogger { Review comment: Overall, I find that this test tailored too much towards specific implementation details, like how many times a certain serializer is called and when. Learning from past mistakes, I found that such tests have a tendency to break fast under future changes and wrongly produce test failures in the absence of real bugs. I would prefer if we could take a more "black box" approach, for example maybe taking one more checkpoint/restore cycle and providing a clearly incompatibel serializer to see if the state was migrated for the checkpoint. This is more stable against changes and tests what we actually want to make sure. ---------------------------------------------------------------- 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: [email protected] With regards, Apache Git Services
