[
https://issues.apache.org/jira/browse/FLINK-5290?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15745166#comment-15745166
]
ASF GitHub Bot commented on FLINK-5290:
---------------------------------------
Github user aljoscha commented on a diff in the pull request:
https://github.com/apache/flink/pull/2966#discussion_r92167823
--- Diff:
flink-streaming-java/src/main/java/org/apache/flink/streaming/api/graph/StreamGraphHasherV2.java
---
@@ -0,0 +1,319 @@
+/*
+ * 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.api.graph;
+
+import com.google.common.hash.HashFunction;
+import com.google.common.hash.Hasher;
+import com.google.common.hash.Hashing;
+import org.apache.flink.runtime.jobgraph.JobVertexID;
+import org.apache.flink.streaming.api.operators.AbstractUdfStreamOperator;
+import org.apache.flink.streaming.api.operators.ChainingStrategy;
+import org.apache.flink.streaming.api.operators.StreamOperator;
+import org.apache.flink.streaming.api.transformations.StreamTransformation;
+import org.apache.flink.streaming.runtime.partitioner.ForwardPartitioner;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.nio.charset.Charset;
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Queue;
+import java.util.Set;
+
+import static org.apache.flink.util.StringUtils.byteToHexString;
+
+/**
+ * StreamGraphHasher from Flink 1.2. This contains duplicated code to
ensure that the algorithm does not change with
+ * future Flink versions.
+ * <p>
+ * DO NOT MODIFY THIS CLASS
+ */
+public class StreamGraphHasherV2 implements StreamGraphHasher {
+
+ private static final Logger LOG =
LoggerFactory.getLogger(StreamGraphHasherV2.class);
+
+ /**
+ * Returns a map with a hash for each {@link StreamNode} of the {@link
+ * StreamGraph}. The hash is used as the {@link JobVertexID} in order to
+ * identify nodes across job submissions if they didn't change.
+ * <p>
--- End diff --
duplicate `<p>` and no blank line. This appears several times in this PR.
> Ensure backwards compatibility of the hashes used to generate JobVertexIds
> --------------------------------------------------------------------------
>
> Key: FLINK-5290
> URL: https://issues.apache.org/jira/browse/FLINK-5290
> Project: Flink
> Issue Type: Sub-task
> Components: State Backends, Checkpointing
> Reporter: Stefan Richter
> Assignee: Stefan Richter
>
> The way in which hashes for JobVertexIds are generated changed between Flink
> 1.1 and 1.2 (parallelism was considered for the hash in 1.1). We need to be
> backwards compatible to old JobVertexId generation so that we can still
> assign state from old savepoints.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
