Github user pnowojski commented on a diff in the pull request:
https://github.com/apache/flink/pull/4851#discussion_r145917513
--- Diff:
flink-streaming-java/src/test/java/org/apache/flink/streaming/runtime/tasks/RestoreStreamTaskTest.java
---
@@ -0,0 +1,325 @@
+/*
+ * 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.streaming.runtime.tasks;
+
+import org.apache.flink.api.common.state.ListState;
+import org.apache.flink.api.common.state.ListStateDescriptor;
+import org.apache.flink.api.common.typeinfo.BasicTypeInfo;
+import org.apache.flink.api.common.typeutils.base.LongSerializer;
+import org.apache.flink.api.common.typeutils.base.StringSerializer;
+import org.apache.flink.runtime.checkpoint.CheckpointMetaData;
+import org.apache.flink.runtime.checkpoint.CheckpointOptions;
+import org.apache.flink.runtime.checkpoint.OperatorSubtaskState;
+import org.apache.flink.runtime.checkpoint.StateAssignmentOperation;
+import org.apache.flink.runtime.checkpoint.TaskStateSnapshot;
+import org.apache.flink.runtime.jobgraph.OperatorID;
+import org.apache.flink.runtime.jobgraph.OperatorInstanceID;
+import org.apache.flink.runtime.operators.testutils.MockInputSplitProvider;
+import org.apache.flink.runtime.state.StateInitializationContext;
+import org.apache.flink.runtime.state.StateSnapshotContext;
+import org.apache.flink.streaming.api.operators.AbstractStreamOperator;
+import org.apache.flink.streaming.api.operators.OneInputStreamOperator;
+import org.apache.flink.streaming.runtime.streamrecord.StreamRecord;
+import org.apache.flink.streaming.util.TestHarnessUtil;
+import org.apache.flink.util.TestLogger;
+
+import org.junit.Test;
+
+import java.util.Collections;
+import java.util.Optional;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.atomic.AtomicLong;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * Tests ensuring correct behaviour of {@link
org.apache.flink.runtime.state.ManagedInitializationContext#isRestored}
+ * method.
+ */
+public class RestoreStreamTaskTest extends TestLogger {
+ @Test
+ public void testRestore() throws Exception {
+ AcknowledgeStreamMockEnvironment environment1 = processRecords(
+ new OperatorID(42L, 42L),
+ new CounterOperator(),
+ new OperatorID(44L, 44L),
+ new CounterOperator(),
+ Optional.empty());
+
+ assertEquals(2,
environment1.getCheckpointStateHandles().getSubtaskStateMappings().size());
+
+ TaskStateSnapshot stateHandles =
environment1.getCheckpointStateHandles();
+
+ try {
+ AcknowledgeStreamMockEnvironment environment2 =
processRecords(
+ new OperatorID(42L, 42L),
+ new RestoreCounterOperator(),
+ new OperatorID(44L, 44L),
+ new RestoreCounterOperator(),
+ Optional.of(stateHandles));
+
+ assertEquals(2,
RestoreCounterOperator.RESTORE_COUNTER.get());
+ }
+ finally {
+ RestoreCounterOperator.RESTORE_COUNTER.getAndSet(0);
+ }
+ }
+
+ @Test
+ public void testRestoreWithNewId() throws Exception {
+ AcknowledgeStreamMockEnvironment environment1 = processRecords(
+ new OperatorID(42L, 42L),
+ new CounterOperator(),
+ new OperatorID(44L, 44L),
+ new CounterOperator(),
+ Optional.empty());
+
+ assertEquals(2,
environment1.getCheckpointStateHandles().getSubtaskStateMappings().size());
+
+ TaskStateSnapshot stateHandles =
environment1.getCheckpointStateHandles();
+
+ try {
+ AcknowledgeStreamMockEnvironment environment2 =
processRecords(
+ new OperatorID(4242L, 4242L),
+ new RestoreCounterOperator(),
+ new OperatorID(44L, 44L),
+ new RestoreCounterOperator(),
+ Optional.of(stateHandles));
+
+ assertEquals(1,
RestoreCounterOperator.RESTORE_COUNTER.get());
+ }
+ finally {
+ RestoreCounterOperator.RESTORE_COUNTER.getAndSet(0);
+ }
+ }
+
+ @Test
+ public void testRestoreAfterScaleUp() throws Exception {
+ OperatorID headOperatorID = new OperatorID(42L, 42L);
+ OperatorID tailOperatorID = new OperatorID(44L, 44L);
+
+ AcknowledgeStreamMockEnvironment environment1 = processRecords(
+ headOperatorID,
+ new CounterOperator(),
+ tailOperatorID,
+ new CounterOperator(),
+ Optional.empty());
+
+ assertEquals(2,
environment1.getCheckpointStateHandles().getSubtaskStateMappings().size());
+
+ // test empty state in case of scale up
+ OperatorSubtaskState emptyHeadOperatorState =
StateAssignmentOperation.operatorSubtaskStateFrom(
+ new OperatorInstanceID(0, headOperatorID),
+ Collections.emptyMap(),
+ Collections.emptyMap(),
+ Collections.emptyMap(),
+ Collections.emptyMap());
+
+ TaskStateSnapshot stateHandles =
environment1.getCheckpointStateHandles();
+ stateHandles.putSubtaskStateByOperatorID(headOperatorID,
emptyHeadOperatorState);
--- End diff --
ad 1. - that's why I have used
`StateAssignmentOperation.operatorSubtaskStateFrom`, to share this logic. I
didn't want to use all of the `StateAssignmentOperation`, because it's
constructor is really annoying to fulfil.
ad 2. - that's a valid concern, however writing ITCases for this might be
also an overkill. And wouldn't it be to necessary to test it against every
state backend, to make sure that there are no introduced quirks during
(de)serialisation?
---
