Github user StephanEwen commented on a diff in the pull request:
https://github.com/apache/flink/pull/2781#discussion_r91053522
--- Diff:
flink-runtime/src/main/java/org/apache/flink/migration/runtime/checkpoint/savepoint/SavepointV0Serializer.java
---
@@ -0,0 +1,390 @@
+/*
+ * 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.migration.runtime.checkpoint.savepoint;
+
+import org.apache.flink.annotation.VisibleForTesting;
+import org.apache.flink.core.fs.Path;
+import org.apache.flink.migration.runtime.checkpoint.KeyGroupState;
+import org.apache.flink.migration.runtime.checkpoint.SubtaskState;
+import org.apache.flink.migration.runtime.checkpoint.TaskState;
+import org.apache.flink.migration.runtime.state.KvStateSnapshot;
+import org.apache.flink.migration.runtime.state.StateHandle;
+import
org.apache.flink.migration.runtime.state.filesystem.AbstractFileStateHandle;
+import
org.apache.flink.migration.runtime.state.memory.SerializedStateHandle;
+import org.apache.flink.migration.state.MigrationKeyGroupStateHandle;
+import org.apache.flink.migration.state.MigrationStreamStateHandle;
+import org.apache.flink.migration.streaming.runtime.tasks.StreamTaskState;
+import
org.apache.flink.migration.streaming.runtime.tasks.StreamTaskStateList;
+import org.apache.flink.migration.util.SerializedValue;
+import org.apache.flink.runtime.checkpoint.savepoint.SavepointSerializer;
+import org.apache.flink.runtime.checkpoint.savepoint.SavepointV1;
+import org.apache.flink.runtime.jobgraph.JobVertexID;
+import org.apache.flink.runtime.state.ChainedStateHandle;
+import org.apache.flink.runtime.state.CheckpointStreamFactory;
+import org.apache.flink.runtime.state.KeyGroupRangeOffsets;
+import org.apache.flink.runtime.state.KeyGroupsStateHandle;
+import org.apache.flink.runtime.state.MultiStreamStateHandle;
+import org.apache.flink.runtime.state.OperatorStateHandle;
+import org.apache.flink.runtime.state.StreamStateHandle;
+import org.apache.flink.runtime.state.filesystem.FileStateHandle;
+import org.apache.flink.runtime.state.memory.ByteStreamStateHandle;
+import org.apache.flink.runtime.state.memory.MemCheckpointStreamFactory;
+import org.apache.flink.util.InstantiationUtil;
+
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+
+/**
+ * <p>
+ * <p>In contrast to previous savepoint versions, this serializer makes
sure
+ * that no default Java serialization is used for serialization.
Therefore, we
+ * don't rely on any involved Java classes to stay the same.
+ */
+public class SavepointV0Serializer implements
SavepointSerializer<SavepointV1> {
+
+ public static final SavepointV0Serializer INSTANCE = new
SavepointV0Serializer();
+ private static final StreamStateHandle SIGNAL_0 = new
ByteStreamStateHandle("SIGNAL_0", new byte[]{0});
+ private static final StreamStateHandle SIGNAL_1 = new
ByteStreamStateHandle("SIGNAL_1", new byte[]{1});
+
+ private static final int MAX_SIZE = 4 * 1024 * 1024;
+
+ private ClassLoader userClassLoader;
--- End diff --
These are shared mutable fields in a singleton object instance. Upon
concurrent use, the different callers will interfere with each other.
I would suggest to try and simply get rid of these fields.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---
