From e84d6ca2df775bb4c93f6c08b345ac30b3a4525b Mon Sep 17 00:00:00 2001
From: Jian He <jianhe@apache.org>
Date: Thu, 3 Dec 2015 19:07:28 -0800
Subject: [PATCH] Add missing file for YARN-4419

---
 .../NonAppendableFSNodeLabelStore.java        | 134 ++++++++++++++++++
 1 file changed, 134 insertions(+)
 create mode 100644 hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/NonAppendableFSNodeLabelStore.java

diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/NonAppendableFSNodeLabelStore.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/NonAppendableFSNodeLabelStore.java
new file mode 100644
index 0000000000..6be571589d
--- /dev/null
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/NonAppendableFSNodeLabelStore.java
@@ -0,0 +1,134 @@
+/**
+ * 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.hadoop.yarn.nodelabels;
+
+import java.io.IOException;
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.yarn.api.records.NodeId;
+import org.apache.hadoop.yarn.api.records.NodeLabel;
+import org.apache.hadoop.yarn.exceptions.YarnException;
+import org.apache.hadoop.yarn.server.api.protocolrecords.AddToClusterNodeLabelsRequest;
+import org.apache.hadoop.yarn.server.api.protocolrecords.ReplaceLabelsOnNodeRequest;
+import org.apache.hadoop.yarn.server.api.protocolrecords.impl.pb.AddToClusterNodeLabelsRequestPBImpl;
+import org.apache.hadoop.yarn.server.api.protocolrecords.impl.pb.ReplaceLabelsOnNodeRequestPBImpl;
+
+public class NonAppendableFSNodeLabelStore extends FileSystemNodeLabelsStore {
+  protected static final Log
+      LOG = LogFactory.getLog(NonAppendableFSNodeLabelStore.class);
+
+  @Override
+  public void close() throws IOException {
+  }
+
+
+  @Override
+  public void recover() throws YarnException,
+      IOException {
+    Path newMirrorPath = new Path(fsWorkingPath, MIRROR_FILENAME + ".new");
+    Path oldMirrorPath = new Path(fsWorkingPath, MIRROR_FILENAME);
+    loadFromMirror(newMirrorPath, oldMirrorPath);
+    
+    // if new mirror exists, remove old mirror and rename new mirror
+    if (fs.exists(newMirrorPath)) {
+      // remove old mirror
+      try {
+        fs.delete(oldMirrorPath, false);
+      } catch (IOException e) {
+        // do nothing
+        if (LOG.isDebugEnabled()) {
+          LOG.debug("Exception while removing old mirror", e);
+        }
+      }
+      
+      // rename new to old
+      fs.rename(newMirrorPath, oldMirrorPath);
+    }
+
+    LOG.info("Node label store recover is completed");
+  }
+  
+  @Override
+  public void updateNodeToLabelsMappings(
+      Map<NodeId, Set<String>> nodeToLabels) throws IOException {
+    writeNewMirror();
+  }
+
+  @Override
+  public void storeNewClusterNodeLabels(List<NodeLabel> labels)
+      throws IOException {
+    writeNewMirror();
+  }
+
+  @Override
+  public void removeClusterNodeLabels(Collection<String> labels)
+      throws IOException {
+    writeNewMirror();
+  }
+
+  private void writeNewMirror() throws IOException {
+    ReentrantReadWriteLock.ReadLock readLock = mgr.readLock;
+    try {
+      // Acquire readlock to make sure we get cluster node labels and
+      // node-to-labels mapping atomically.
+      readLock.lock();
+      List<NodeLabel> nodeLabels = mgr.getClusterNodeLabels();
+      Map<NodeId, Set<String>> nodeToLabels = mgr.getNodeLabels();
+      
+      // Write mirror to mirror.new.tmp file
+      Path newTmpPath = new Path(fsWorkingPath, MIRROR_FILENAME + ".new.tmp"); 
+      FSDataOutputStream os = fs
+          .create(newTmpPath, true);
+      ((AddToClusterNodeLabelsRequestPBImpl) AddToClusterNodeLabelsRequest
+          .newInstance(nodeLabels)).getProto().writeDelimitedTo(os);
+
+      if (mgr.isCentralizedConfiguration()) {
+        // Only save node-to-labels mapping while using centralized configuration
+        ((ReplaceLabelsOnNodeRequestPBImpl) ReplaceLabelsOnNodeRequest
+            .newInstance(nodeToLabels)).getProto().writeDelimitedTo(os);
+      }
+      
+      os.close();
+      
+      // Rename mirror.new.tmp to mirror.new (will remove .new if it's existed)
+      Path newPath = new Path(fsWorkingPath, MIRROR_FILENAME + ".new"); 
+      if (fs.exists(newPath)) {
+        fs.delete(newPath, false);
+      }
+      fs.rename(newTmpPath, newPath);
+      
+      // Remove existing mirror and rename mirror.new to mirror
+      Path mirrorPath = new Path(fsWorkingPath, MIRROR_FILENAME);
+      if (fs.exists(mirrorPath)) {
+        fs.delete(mirrorPath, false);
+      }
+      fs.rename(newPath, mirrorPath);
+    } finally {
+      readLock.unlock();
+    }
+  }
+}