YARN-7988. Refactor FSNodeLabelStore code for Node Attributes store support. Contributed by Bibin A Chundatt.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/CommonNodeLabelsManager.java

@@ -234,7 +234,10 @@ public class CommonNodeLabelsManager extends AbstractService {
     return initNodeLabelStoreInProgress;
   }
 
-  boolean isCentralizedConfiguration() {
+  /**
+   * @return true if node label configuration type is not distributed.
+   */
+  public boolean isCentralizedConfiguration() {
     return isCentralizedNodeLabelConfiguration;
   }
 
@@ -245,8 +248,7 @@ public class CommonNodeLabelsManager extends AbstractService {
                 conf.getClass(YarnConfiguration.FS_NODE_LABELS_STORE_IMPL_CLASS,
                     FileSystemNodeLabelsStore.class, NodeLabelsStore.class),
                 conf);
-    this.store.setNodeLabelsManager(this);
-    this.store.init(conf);
+    this.store.init(conf, this);
     this.store.recover();
   }
 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/FileSystemNodeLabelsStore.java

@@ -18,275 +18,89 @@
 
 package org.apache.hadoop.yarn.nodelabels;
 
-import java.io.EOFException;
-import java.io.FileNotFoundException;
-import java.io.IOException;
-import java.util.Collection;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.fs.FSDataInputStream;
-import org.apache.hadoop.fs.FSDataOutputStream;
-import org.apache.hadoop.fs.FileSystem;
-import org.apache.hadoop.fs.LocalFileSystem;
 import org.apache.hadoop.fs.Path;
-import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.yarn.api.records.NodeId;
 import org.apache.hadoop.yarn.api.records.NodeLabel;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.exceptions.YarnException;
-import org.apache.hadoop.yarn.proto.YarnServerResourceManagerServiceProtos.AddToClusterNodeLabelsRequestProto;
-import org.apache.hadoop.yarn.proto.YarnServerResourceManagerServiceProtos.RemoveFromClusterNodeLabelsRequestProto;
-import org.apache.hadoop.yarn.proto.YarnServerResourceManagerServiceProtos.ReplaceLabelsOnNodeRequestProto;
-import org.apache.hadoop.yarn.server.api.protocolrecords.AddToClusterNodeLabelsRequest;
-import org.apache.hadoop.yarn.server.api.protocolrecords.RemoveFromClusterNodeLabelsRequest;
-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.RemoveFromClusterNodeLabelsRequestPBImpl;
-import org.apache.hadoop.yarn.server.api.protocolrecords.impl.pb.ReplaceLabelsOnNodeRequestPBImpl;
+import org.apache.hadoop.yarn.nodelabels.store.AbstractFSNodeStore;
+import org.apache.hadoop.yarn.nodelabels.store.FSStoreOpHandler;
 
-import com.google.common.collect.Sets;
+import org.apache.hadoop.yarn.nodelabels.store.op.AddClusterLabelOp;
+import org.apache.hadoop.yarn.nodelabels.store.FSStoreOpHandler.StoreType;
+import org.apache.hadoop.yarn.nodelabels.store.op.NodeToLabelOp;
+import org.apache.hadoop.yarn.nodelabels.store.op.RemoveClusterLabelOp;
 
-public class FileSystemNodeLabelsStore extends NodeLabelsStore {
-  protected static final Log LOG = LogFactory.getLog(FileSystemNodeLabelsStore.class);
+import java.io.IOException;
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+public class FileSystemNodeLabelsStore
+    extends AbstractFSNodeStore<CommonNodeLabelsManager>
+    implements NodeLabelsStore {
+  protected static final Log LOG =
+      LogFactory.getLog(FileSystemNodeLabelsStore.class);
 
   protected static final String DEFAULT_DIR_NAME = "node-labels";
   protected static final String MIRROR_FILENAME = "nodelabel.mirror";
   protected static final String EDITLOG_FILENAME = "nodelabel.editlog";
-  
-  protected enum SerializedLogType {
-    ADD_LABELS, NODE_TO_LABELS, REMOVE_LABELS
+
+  FileSystemNodeLabelsStore() {
+    super(StoreType.NODE_LABEL_STORE);
   }
 
-  Path fsWorkingPath;
-  FileSystem fs;
-  private FSDataOutputStream editlogOs;
-  private Path editLogPath;
-  
   private String getDefaultFSNodeLabelsRootDir() throws IOException {
     // default is in local: /tmp/hadoop-yarn-${user}/node-labels/
-    return "file:///tmp/hadoop-yarn-"
-        + UserGroupInformation.getCurrentUser().getShortUserName() + "/"
-        + DEFAULT_DIR_NAME;
+    return "file:///tmp/hadoop-yarn-" + UserGroupInformation.getCurrentUser()
+        .getShortUserName() + "/" + DEFAULT_DIR_NAME;
   }
 
   @Override
-  public void init(Configuration conf) throws Exception {
-    fsWorkingPath =
-        new Path(conf.get(YarnConfiguration.FS_NODE_LABELS_STORE_ROOT_DIR,
-            getDefaultFSNodeLabelsRootDir()));
-
-    setFileSystem(conf);
-
-    // mkdir of root dir path
-    fs.mkdirs(fsWorkingPath);
+  public void init(Configuration conf, CommonNodeLabelsManager mgr)
+      throws Exception {
+    StoreSchema schema = new StoreSchema(EDITLOG_FILENAME, MIRROR_FILENAME);
+    initStore(conf, new Path(
+        conf.get(YarnConfiguration.FS_NODE_LABELS_STORE_ROOT_DIR,
+            getDefaultFSNodeLabelsRootDir())), schema, mgr);
   }
 
   @Override
   public void close() throws IOException {
-    IOUtils.cleanup(LOG, fs, editlogOs);
-  }
-
-  void setFileSystem(Configuration conf) throws IOException {
-    Configuration confCopy = new Configuration(conf);
-    fs = fsWorkingPath.getFileSystem(confCopy);
-
-    // if it's local file system, use RawLocalFileSystem instead of
-    // LocalFileSystem, the latter one doesn't support append.
-    if (fs.getScheme().equals("file")) {
-      fs = ((LocalFileSystem)fs).getRaw();
-    }
-  }
-  
-  private void ensureAppendEditlogFile() throws IOException {
-    editlogOs = fs.append(editLogPath);
-  }
-  
-  private void ensureCloseEditlogFile() throws IOException {
-    editlogOs.close();
+    super.closeFSStore();
   }
 
   @Override
-  public void updateNodeToLabelsMappings(
-      Map<NodeId, Set<String>> nodeToLabels) throws IOException {
-    try {
-      ensureAppendEditlogFile();
-      editlogOs.writeInt(SerializedLogType.NODE_TO_LABELS.ordinal());
-      ((ReplaceLabelsOnNodeRequestPBImpl) ReplaceLabelsOnNodeRequest
-          .newInstance(nodeToLabels)).getProto().writeDelimitedTo(editlogOs);
-    } finally {
-      ensureCloseEditlogFile();
-    }
+  public void updateNodeToLabelsMappings(Map<NodeId, Set<String>> nodeToLabels)
+      throws IOException {
+    NodeToLabelOp op = new NodeToLabelOp();
+    writeToLog(op.setNodeToLabels(nodeToLabels));
   }
 
   @Override
   public void storeNewClusterNodeLabels(List<NodeLabel> labels)
       throws IOException {
-    try {
-      ensureAppendEditlogFile();
-      editlogOs.writeInt(SerializedLogType.ADD_LABELS.ordinal());
-      ((AddToClusterNodeLabelsRequestPBImpl) AddToClusterNodeLabelsRequest
-          .newInstance(labels)).getProto().writeDelimitedTo(editlogOs);
-    } finally {
-      ensureCloseEditlogFile();
-    }
+    AddClusterLabelOp op = new AddClusterLabelOp();
+    writeToLog(op.setLabels(labels));
   }
 
   @Override
   public void removeClusterNodeLabels(Collection<String> labels)
       throws IOException {
-    try {
-      ensureAppendEditlogFile();
-      editlogOs.writeInt(SerializedLogType.REMOVE_LABELS.ordinal());
-      ((RemoveFromClusterNodeLabelsRequestPBImpl) RemoveFromClusterNodeLabelsRequest.newInstance(Sets
-          .newHashSet(labels.iterator()))).getProto().writeDelimitedTo(editlogOs);
-    } finally {
-      ensureCloseEditlogFile();
-    }
-  }
-  
-  protected void loadFromMirror(Path newMirrorPath, Path oldMirrorPath)
-      throws IOException {
-    // If mirror.new exists, read from mirror.new,
-    FSDataInputStream is = null;
-    try {
-      is = fs.open(newMirrorPath);
-    } catch (FileNotFoundException e) {
-      try {
-        is = fs.open(oldMirrorPath);
-      } catch (FileNotFoundException ignored) {
-
-      }
-    }
-    if (null != is) {
-      List<NodeLabel> labels = new AddToClusterNodeLabelsRequestPBImpl(
-          AddToClusterNodeLabelsRequestProto.parseDelimitedFrom(is))
-              .getNodeLabels();
-      mgr.addToCluserNodeLabels(labels);
-
-      if (mgr.isCentralizedConfiguration()) {
-        // Only load node to labels mapping while using centralized configuration
-        Map<NodeId, Set<String>> nodeToLabels =
-            new ReplaceLabelsOnNodeRequestPBImpl(
-                ReplaceLabelsOnNodeRequestProto.parseDelimitedFrom(is))
-                  .getNodeToLabels();
-        mgr.replaceLabelsOnNode(nodeToLabels);
-      }
-      is.close();
-    }
+    RemoveClusterLabelOp op = new RemoveClusterLabelOp();
+    writeToLog(op.setLabels(labels));
   }
 
   /* (non-Javadoc)
-   * @see org.apache.hadoop.yarn.nodelabels.NodeLabelsStore#recover(boolean)
-   */
-  @Override
-  public void recover() throws YarnException,
-      IOException {
-    /*
-     * Steps of recover
-     * 1) Read from last mirror (from mirror or mirror.old)
-     * 2) Read from last edit log, and apply such edit log
-     * 3) Write new mirror to mirror.writing
-     * 4) Rename mirror to mirror.old
-     * 5) Move mirror.writing to mirror
-     * 6) Remove mirror.old
-     * 7) Remove edit log and create a new empty edit log 
+     * @see org.apache.hadoop.yarn.nodelabels.NodeLabelsStore#recover(boolean)
      */
-    
-    // Open mirror from serialized file
-    Path mirrorPath = new Path(fsWorkingPath, MIRROR_FILENAME);
-    Path oldMirrorPath = new Path(fsWorkingPath, MIRROR_FILENAME + ".old");
-    
-    loadFromMirror(mirrorPath, oldMirrorPath);
-
-    // Open and process editlog
-    editLogPath = new Path(fsWorkingPath, EDITLOG_FILENAME);
-    FSDataInputStream is;
-    try {
-      is = fs.open(editLogPath);
-    } catch (FileNotFoundException e) {
-      is = null;
-    }
-    if (null != is) {
-
-      while (true) {
-        try {
-          // read edit log one by one
-          SerializedLogType type = SerializedLogType.values()[is.readInt()];
-          
-          switch (type) {
-          case ADD_LABELS: {
-            List<NodeLabel> labels =
-                new AddToClusterNodeLabelsRequestPBImpl(
-                    AddToClusterNodeLabelsRequestProto.parseDelimitedFrom(is))
-                    .getNodeLabels();
-            mgr.addToCluserNodeLabels(labels);
-            break;
-          }
-          case REMOVE_LABELS: {
-            Collection<String> labels =
-                RemoveFromClusterNodeLabelsRequestProto.parseDelimitedFrom(is)
-                    .getNodeLabelsList();
-            mgr.removeFromClusterNodeLabels(labels);
-            break;
-          }
-          case NODE_TO_LABELS: {
-            Map<NodeId, Set<String>> map =
-                new ReplaceLabelsOnNodeRequestPBImpl(
-                    ReplaceLabelsOnNodeRequestProto.parseDelimitedFrom(is))
-                    .getNodeToLabels();
-            if (mgr.isCentralizedConfiguration()) {
-              /*
-               * In case of Distributed NodeLabels setup,
-               * ignoreNodeToLabelsMappings will be set to true and recover will
-               * be invoked. As RM will collect the node labels from NM through
-               * registration/HB
-               */
-              mgr.replaceLabelsOnNode(map);
-            }
-            break;
-          }
-          }
-        } catch (EOFException e) {
-          // EOF hit, break
-          break;
-        }
-      }
-      is.close();
-    }
-
-    // Serialize current mirror to mirror.writing
-    Path writingMirrorPath = new Path(fsWorkingPath, MIRROR_FILENAME + ".writing");
-    FSDataOutputStream os = fs.create(writingMirrorPath, true);
-    ((AddToClusterNodeLabelsRequestPBImpl) AddToClusterNodeLabelsRequestPBImpl
-        .newInstance(mgr.getClusterNodeLabels())).getProto().writeDelimitedTo(os);
-    ((ReplaceLabelsOnNodeRequestPBImpl) ReplaceLabelsOnNodeRequest
-        .newInstance(mgr.getNodeLabels())).getProto().writeDelimitedTo(os);
-    os.close();
-    
-    // Move mirror to mirror.old
-    if (fs.exists(mirrorPath)) {
-      fs.delete(oldMirrorPath, false);
-      fs.rename(mirrorPath, oldMirrorPath);
-    }
-    
-    // move mirror.writing to mirror
-    fs.rename(writingMirrorPath, mirrorPath);
-    fs.delete(writingMirrorPath, false);
-    
-    // remove mirror.old
-    fs.delete(oldMirrorPath, false);
-    
-    // create a new editlog file
-    editlogOs = fs.create(editLogPath, true);
-    editlogOs.close();
-    
-    LOG.info("Finished write mirror at:" + mirrorPath.toString());
-    LOG.info("Finished create editlog file at:" + editLogPath.toString());
+  @Override
+  public void recover() throws YarnException, IOException {
+    super.recoverFromStore();
   }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/NodeLabelsStore.java

@@ -30,25 +30,27 @@ import org.apache.hadoop.yarn.api.records.NodeId;
 import org.apache.hadoop.yarn.api.records.NodeLabel;
 import org.apache.hadoop.yarn.exceptions.YarnException;
 
-public abstract class NodeLabelsStore implements Closeable {
-  protected CommonNodeLabelsManager mgr;
-  
+/**
+ * Interface class for Node label store.
+ */
+public interface NodeLabelsStore extends Closeable {
+
   /**
-   * Store node {@literal ->} label
+   * Store node {@literal ->} label.
    */
-  public abstract void updateNodeToLabelsMappings(
+  void updateNodeToLabelsMappings(
       Map<NodeId, Set<String>> nodeToLabels) throws IOException;
 
   /**
-   * Store new labels
+   * Store new labels.
    */
-  public abstract void storeNewClusterNodeLabels(List<NodeLabel> label)
+  void storeNewClusterNodeLabels(List<NodeLabel> label)
       throws IOException;
 
   /**
-   * Remove labels
+   * Remove labels.
    */
-  public abstract void removeClusterNodeLabels(Collection<String> labels)
+  void removeClusterNodeLabels(Collection<String> labels)
       throws IOException;
 
   /**
@@ -56,16 +58,14 @@ public abstract class NodeLabelsStore implements Closeable {
    * ignoreNodeToLabelsMappings is true then node to labels mappings should not
    * be recovered. In case of Distributed NodeLabels setup
    * ignoreNodeToLabelsMappings will be set to true and recover will be invoked
-   * as RM will collect the node labels from NM through registration/HB
+   * as RM will collect the node labels from NM through registration/HB.
    *
    * @throws IOException
    * @throws YarnException
    */
-  public abstract void recover() throws IOException, YarnException;
-  
-  public void init(Configuration conf) throws Exception {}
+  void recover() throws IOException, YarnException;
+
+  void init(Configuration conf, CommonNodeLabelsManager mgr)
+      throws Exception;
 
-  public void setNodeLabelsManager(CommonNodeLabelsManager mgr) {
-    this.mgr = mgr;
-  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/NonAppendableFSNodeLabelStore.java

@@ -18,13 +18,6 @@
 
 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;
@@ -32,11 +25,19 @@ 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;
+import org.apache.hadoop.yarn.nodelabels.store.FSStoreOpHandler;
+import org.apache.hadoop.yarn.nodelabels.store.StoreOp;
+
+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;
 
+/**
+ * Store implementation for Non Appendable File Store
+ */
 public class NonAppendableFSNodeLabelStore extends FileSystemNodeLabelsStore {
   protected static final Log
       LOG = LogFactory.getLog(NonAppendableFSNodeLabelStore.class);
@@ -52,7 +53,7 @@ public class NonAppendableFSNodeLabelStore extends FileSystemNodeLabelsStore {
     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
@@ -91,29 +92,18 @@ public class NonAppendableFSNodeLabelStore extends FileSystemNodeLabelsStore {
   }
 
   private void writeNewMirror() throws IOException {
-    ReentrantReadWriteLock.ReadLock readLock = mgr.readLock;
+    ReentrantReadWriteLock.ReadLock readLock = manager.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);
+      Path newTmpPath = new Path(fsWorkingPath, MIRROR_FILENAME + ".new.tmp");
+      try (FSDataOutputStream os = fs.create(newTmpPath, true)) {
+        StoreOp op = FSStoreOpHandler.getMirrorOp(getStoreType());
+        op.write(os, manager);
       }
       
-      os.close();
-      
       // Rename mirror.new.tmp to mirror.new (will remove .new if it's existed)
       Path newPath = new Path(fsWorkingPath, MIRROR_FILENAME + ".new"); 
       fs.delete(newPath, false);

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/store/AbstractFSNodeStore.java

@@ -0,0 +1,213 @@
+/**
+ * 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.store;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.LocalFileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.IOUtils;
+import org.apache.hadoop.yarn.nodelabels.store.op.FSNodeStoreLogOp;
+import org.apache.hadoop.yarn.nodelabels.store.FSStoreOpHandler.StoreType;
+
+import java.io.EOFException;
+import java.io.IOException;
+
+/**
+ * Abstract class for File System based store.
+ *
+ * @param <M> manager filesystem store.Currently nodelabel will use
+ *           CommonNodeLabelManager.
+ */
+public abstract class AbstractFSNodeStore<M> {
+
+  protected static final Log LOG = LogFactory.getLog(AbstractFSNodeStore.class);
+
+  private StoreType storeType;
+  private FSDataOutputStream editlogOs;
+
+  private Path editLogPath;
+  private StoreSchema schema;
+
+  protected M manager;
+  protected Path fsWorkingPath;
+  protected FileSystem fs;
+
+  public AbstractFSNodeStore(StoreType storeType) {
+    this.storeType = storeType;
+  }
+
+  protected void initStore(Configuration conf, Path fsStorePath,
+      StoreSchema schma, M mgr) throws IOException {
+    this.schema = schma;
+    this.fsWorkingPath = fsStorePath;
+    this.manager = mgr;
+    initFileSystem(conf);
+    // mkdir of root dir path
+    fs.mkdirs(fsWorkingPath);
+
+  }
+
+  /**
+   * Filesystem store schema define the log name and mirror name.
+   */
+  public static class StoreSchema {
+    private String editLogName;
+    private String mirrorName;
+
+    public StoreSchema(String editLogName, String mirrorName) {
+      this.editLogName = editLogName;
+      this.mirrorName = mirrorName;
+    }
+  }
+
+  public void initFileSystem(Configuration conf) throws IOException {
+    Configuration confCopy = new Configuration(conf);
+    fs = fsWorkingPath.getFileSystem(confCopy);
+    // if it's local file system, use RawLocalFileSystem instead of
+    // LocalFileSystem, the latter one doesn't support append.
+    if (fs.getScheme().equals("file")) {
+      fs = ((LocalFileSystem) fs).getRaw();
+    }
+  }
+
+  protected void writeToLog(FSNodeStoreLogOp op) throws IOException {
+    try {
+      ensureAppendEditLogFile();
+      editlogOs.writeInt(op.getOpCode());
+      op.write(editlogOs, manager);
+    } finally {
+      ensureCloseEditlogFile();
+    }
+  }
+
+  protected void ensureAppendEditLogFile() throws IOException {
+    editlogOs = fs.append(editLogPath);
+  }
+
+  protected void ensureCloseEditlogFile() throws IOException {
+    editlogOs.close();
+  }
+
+  protected void loadFromMirror(Path newMirrorPath, Path oldMirrorPath)
+      throws IOException {
+    // If mirror.new exists, read from mirror.new
+    Path mirrorToRead = fs.exists(newMirrorPath) ?
+        newMirrorPath :
+        fs.exists(oldMirrorPath) ? oldMirrorPath : null;
+    if (mirrorToRead != null) {
+      try (FSDataInputStream is = fs.open(mirrorToRead)) {
+        StoreOp op = FSStoreOpHandler.getMirrorOp(storeType);
+        op.recover(is, manager);
+      }
+    }
+  }
+
+  protected StoreType getStoreType() {
+    return storeType;
+  }
+
+  public Path getFsWorkingPath() {
+    return fsWorkingPath;
+  }
+
+  protected void recoverFromStore() throws IOException {
+        /*
+     * Steps of recover
+     * 1) Read from last mirror (from mirror or mirror.old)
+     * 2) Read from last edit log, and apply such edit log
+     * 3) Write new mirror to mirror.writing
+     * 4) Rename mirror to mirror.old
+     * 5) Move mirror.writing to mirror
+     * 6) Remove mirror.old
+     * 7) Remove edit log and create a new empty edit log
+     */
+
+    // Open mirror from serialized file
+    Path mirrorPath = new Path(fsWorkingPath, schema.mirrorName);
+    Path oldMirrorPath = new Path(fsWorkingPath, schema.mirrorName + ".old");
+
+    loadFromMirror(mirrorPath, oldMirrorPath);
+
+    // Open and process editlog
+    editLogPath = new Path(fsWorkingPath, schema.editLogName);
+
+    loadManagerFromEditLog(editLogPath);
+
+    // Serialize current mirror to mirror.writing
+    Path writingMirrorPath =
+        new Path(fsWorkingPath, schema.mirrorName + ".writing");
+
+    try(FSDataOutputStream os = fs.create(writingMirrorPath, true)){
+      StoreOp op = FSStoreOpHandler.getMirrorOp(storeType);
+      op.write(os, manager);
+    }
+    // Move mirror to mirror.old
+    if (fs.exists(mirrorPath)) {
+      fs.delete(oldMirrorPath, false);
+      fs.rename(mirrorPath, oldMirrorPath);
+    }
+
+    // move mirror.writing to mirror
+    fs.rename(writingMirrorPath, mirrorPath);
+    fs.delete(writingMirrorPath, false);
+
+    // remove mirror.old
+    fs.delete(oldMirrorPath, false);
+
+    // create a new editlog file
+    editlogOs = fs.create(editLogPath, true);
+    editlogOs.close();
+
+    LOG.info("Finished write mirror at:" + mirrorPath.toString());
+    LOG.info("Finished create editlog file at:" + editLogPath.toString());
+  }
+
+  protected void loadManagerFromEditLog(Path editLogPath) throws IOException {
+    if (!fs.exists(editLogPath)) {
+      return;
+    }
+    try (FSDataInputStream is = fs.open(editLogPath)) {
+      while (true) {
+        try {
+          StoreOp storeOp = FSStoreOpHandler.get(is.readInt(),storeType);
+          storeOp.recover(is, manager);
+        } catch (EOFException e) {
+          // EOF hit, break
+          break;
+        }
+      }
+    }
+  }
+
+  public FileSystem getFs() {
+    return fs;
+  }
+
+  public void setFs(FileSystem fs) {
+    this.fs = fs;
+  }
+
+  protected void closeFSStore() {
+    IOUtils.closeStreams(fs, editlogOs);
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/store/FSStoreOpHandler.java

@@ -0,0 +1,108 @@
+/**
+ * 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.store;
+
+import static org.apache.hadoop.yarn.nodelabels.store.FSStoreOpHandler
+    .StoreType.NODE_LABEL_STORE;
+import org.apache.hadoop.yarn.nodelabels.store.op.AddClusterLabelOp;
+import org.apache.hadoop.yarn.nodelabels.store.op.FSNodeStoreLogOp;
+import org.apache.hadoop.yarn.nodelabels.store.op.NodeLabelMirrorOp;
+import org.apache.hadoop.yarn.nodelabels.store.op.NodeToLabelOp;
+import org.apache.hadoop.yarn.nodelabels.store.op.RemoveClusterLabelOp;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * File system store op handler.
+ */
+public class FSStoreOpHandler {
+
+  private static Map<StoreType, Map<Integer, Class<? extends FSNodeStoreLogOp>>>
+      editLogOp;
+  private static Map<StoreType, Class<? extends FSNodeStoreLogOp>> mirrorOp;
+
+  public enum StoreType {
+    NODE_LABEL_STORE,
+    NODE_LABEL_ATTRIBUTE;
+  }
+
+  static {
+    editLogOp = new HashMap<>();
+    mirrorOp = new HashMap<>();
+
+    // registerLog edit log operation
+    registerLog(NODE_LABEL_STORE, AddClusterLabelOp.OPCODE, AddClusterLabelOp.class);
+    registerLog(NODE_LABEL_STORE, NodeToLabelOp.OPCODE, NodeToLabelOp.class);
+    registerLog(NODE_LABEL_STORE, RemoveClusterLabelOp.OPCODE, RemoveClusterLabelOp.class);
+
+    // registerLog Mirror op
+
+    registerMirror(NODE_LABEL_STORE, NodeLabelMirrorOp.class);
+  }
+
+  private static void registerMirror(StoreType type,
+      Class<? extends FSNodeStoreLogOp> clazz) {
+    mirrorOp.put(type, clazz);
+  }
+
+  private static void registerLog(StoreType type, int opcode,
+      Class<? extends FSNodeStoreLogOp> clazz) {
+    Map<Integer, Class<? extends FSNodeStoreLogOp>> ops = editLogOp.get(type);
+    Integer code = Integer.valueOf(opcode);
+    if (ops == null) {
+      Map<Integer, Class<? extends FSNodeStoreLogOp>> newOps = new HashMap<>();
+      newOps.put(code, clazz);
+      editLogOp.put(type, newOps);
+    } else {
+      ops.put(code, clazz);
+    }
+  }
+
+  /**
+   * Get mirror operation of store Type.
+   *
+   * @param storeType
+   * @return instance of FSNodeStoreLogOp.
+   */
+  public static FSNodeStoreLogOp getMirrorOp(StoreType storeType) {
+    return newInstance(mirrorOp.get(storeType));
+  }
+
+  /**
+   * Will return StoreOp instance basead on opCode and StoreType.
+   * @param opCode
+   * @param storeType
+   * @return instance of FSNodeStoreLogOp.
+   */
+  public static FSNodeStoreLogOp get(int opCode, StoreType storeType) {
+    return newInstance(editLogOp.get(storeType).get(opCode));
+  }
+
+  private static <T extends FSNodeStoreLogOp> T newInstance(Class<T> clazz) {
+    FSNodeStoreLogOp instance = null;
+    if (clazz != null) {
+      try {
+        instance = clazz.newInstance();
+      } catch (Exception ex) {
+        throw new RuntimeException("Failed to instantiate " + clazz, ex);
+      }
+    }
+    return (T) instance;
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/store/StoreOp.java

@@ -0,0 +1,49 @@
+/**
+ * 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.store;
+
+import java.io.IOException;
+
+/**
+ * Define the interface for store activity.
+ * Used by for FileSystem based operation.
+ *
+ * @param <W> write to be done to
+ * @param <R> read to be done from
+ * @param <M> manager used
+ */
+public interface StoreOp<W, R, M> {
+
+  /**
+   * Write operation to persistent storage
+   *
+   * @param write write to be done to
+   * @param mgr manager used by store
+   * @throws IOException
+   */
+  void write(W write, M mgr) throws IOException;
+
+  /**
+   * Read and populate StoreOp
+   *
+   * @param read read to be done from
+   * @param mgr  manager used by store
+   * @throws IOException
+   */
+  void recover(R read, M mgr) throws IOException;
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/store/op/AddClusterLabelOp.java

@@ -0,0 +1,73 @@
+/**
+ * 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.store.op;
+
+import org.apache.hadoop.yarn.api.records.NodeLabel;
+import org.apache.hadoop.yarn.nodelabels.CommonNodeLabelsManager;
+import org.apache.hadoop.yarn.proto.YarnServerResourceManagerServiceProtos;
+import org.apache.hadoop.yarn.server.api.protocolrecords
+    .AddToClusterNodeLabelsRequest;
+import org.apache.hadoop.yarn.server.api.protocolrecords.impl.pb
+    .AddToClusterNodeLabelsRequestPBImpl;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.List;
+
+/**
+ * Add label operation for file system.
+ */
+public class AddClusterLabelOp
+    extends FSNodeStoreLogOp<CommonNodeLabelsManager> {
+
+  private List<NodeLabel> labels;
+
+  public static final int OPCODE = 0;
+
+  @Override
+  public void write(OutputStream os, CommonNodeLabelsManager mgr)
+      throws IOException {
+    ((AddToClusterNodeLabelsRequestPBImpl) AddToClusterNodeLabelsRequest
+        .newInstance(labels)).getProto().writeDelimitedTo(os);
+  }
+
+  @Override
+  public void recover(InputStream is, CommonNodeLabelsManager mgr)
+      throws IOException {
+    labels = new AddToClusterNodeLabelsRequestPBImpl(
+        YarnServerResourceManagerServiceProtos
+            .AddToClusterNodeLabelsRequestProto
+            .parseDelimitedFrom(is)).getNodeLabels();
+    mgr.addToCluserNodeLabels(labels);
+  }
+
+  public AddClusterLabelOp setLabels(List<NodeLabel> labels) {
+    this.labels = labels;
+    return this;
+  }
+
+  public List<NodeLabel> getLabels() {
+    return labels;
+  }
+
+  @Override
+  public int getOpCode() {
+    return OPCODE;
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/store/op/FSNodeStoreLogOp.java

@@ -0,0 +1,35 @@
+/**
+ * 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.store.op;
+
+import org.apache.hadoop.yarn.nodelabels.store.StoreOp;
+
+import java.io.InputStream;
+import java.io.OutputStream;
+
+/**
+ * Defines all FileSystem editlog operation. All node label and attribute
+ * store write or read operation will be defined in this class.
+ *
+ * @param <M> Manager used for each operation.
+ */
+public abstract class FSNodeStoreLogOp<M>
+    implements StoreOp<OutputStream, InputStream, M> {
+
+  public abstract int getOpCode();
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/store/op/NodeLabelMirrorOp.java

@@ -0,0 +1,82 @@
+/**
+ * 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.store.op;
+
+import org.apache.hadoop.yarn.api.records.NodeId;
+import org.apache.hadoop.yarn.api.records.NodeLabel;
+import org.apache.hadoop.yarn.nodelabels.CommonNodeLabelsManager;
+import org.apache.hadoop.yarn.proto.YarnServerResourceManagerServiceProtos;
+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;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+public class NodeLabelMirrorOp
+    extends FSNodeStoreLogOp<CommonNodeLabelsManager> {
+
+  public NodeLabelMirrorOp() {
+    super();
+  }
+
+  @Override
+  public void write(OutputStream os, CommonNodeLabelsManager mgr)
+      throws IOException {
+    ((AddToClusterNodeLabelsRequestPBImpl) AddToClusterNodeLabelsRequestPBImpl
+        .newInstance(mgr.getClusterNodeLabels())).getProto()
+        .writeDelimitedTo(os);
+    if (mgr.isCentralizedConfiguration()) {
+      ((ReplaceLabelsOnNodeRequestPBImpl) ReplaceLabelsOnNodeRequest
+          .newInstance(mgr.getNodeLabels())).getProto().writeDelimitedTo(os);
+    }
+  }
+
+  @Override
+  public void recover(InputStream is, CommonNodeLabelsManager mgr)
+      throws IOException {
+    List<NodeLabel> labels = new AddToClusterNodeLabelsRequestPBImpl(
+        YarnServerResourceManagerServiceProtos
+            .AddToClusterNodeLabelsRequestProto
+            .parseDelimitedFrom(is)).getNodeLabels();
+    mgr.addToCluserNodeLabels(labels);
+
+    if (mgr.isCentralizedConfiguration()) {
+      // Only load node to labels mapping while using centralized
+      // configuration
+      Map<NodeId, Set<String>> nodeToLabels =
+          new ReplaceLabelsOnNodeRequestPBImpl(
+              YarnServerResourceManagerServiceProtos
+                  .ReplaceLabelsOnNodeRequestProto
+                  .parseDelimitedFrom(is)).getNodeToLabels();
+      mgr.replaceLabelsOnNode(nodeToLabels);
+    }
+  }
+
+  @Override
+  public int getOpCode() {
+    return -1;
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/store/op/NodeToLabelOp.java

@@ -0,0 +1,75 @@
+/**
+ * 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.store.op;
+
+import org.apache.hadoop.yarn.api.records.NodeId;
+import org.apache.hadoop.yarn.nodelabels.CommonNodeLabelsManager;
+import org.apache.hadoop.yarn.proto.YarnServerResourceManagerServiceProtos;
+import org.apache.hadoop.yarn.server.api.protocolrecords
+    .ReplaceLabelsOnNodeRequest;
+import org.apache.hadoop.yarn.server.api.protocolrecords.impl.pb
+    .ReplaceLabelsOnNodeRequestPBImpl;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Node to label mapping store operation for label.
+ */
+public class NodeToLabelOp
+    extends FSNodeStoreLogOp<CommonNodeLabelsManager> {
+
+  private Map<NodeId, Set<String>> nodeToLabels;
+  public static final int OPCODE = 1;
+
+  @Override
+  public void write(OutputStream os, CommonNodeLabelsManager mgr)
+      throws IOException {
+    ((ReplaceLabelsOnNodeRequestPBImpl) ReplaceLabelsOnNodeRequest
+        .newInstance(nodeToLabels)).getProto().writeDelimitedTo(os);
+  }
+
+  @Override
+  public void recover(InputStream is, CommonNodeLabelsManager mgr)
+      throws IOException {
+    nodeToLabels = new ReplaceLabelsOnNodeRequestPBImpl(
+        YarnServerResourceManagerServiceProtos.ReplaceLabelsOnNodeRequestProto
+            .parseDelimitedFrom(is)).getNodeToLabels();
+    if (mgr.isCentralizedConfiguration()) {
+      mgr.replaceLabelsOnNode(nodeToLabels);
+    }
+  }
+
+  public NodeToLabelOp setNodeToLabels(
+      Map<NodeId, Set<String>> nodeToLabels) {
+    this.nodeToLabels = nodeToLabels;
+    return this;
+  }
+
+  public Map<NodeId, Set<String>> getNodeToLabels() {
+    return nodeToLabels;
+  }
+
+  @Override
+  public int getOpCode() {
+    return OPCODE;
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/store/op/RemoveClusterLabelOp.java

@@ -0,0 +1,75 @@
+/**
+ * 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.store.op;
+
+import com.google.common.collect.Sets;
+import org.apache.hadoop.yarn.nodelabels.CommonNodeLabelsManager;
+import org.apache.hadoop.yarn.proto.YarnServerResourceManagerServiceProtos;
+import org.apache.hadoop.yarn.server.api.protocolrecords
+    .RemoveFromClusterNodeLabelsRequest;
+import org.apache.hadoop.yarn.server.api.protocolrecords.impl.pb
+    .RemoveFromClusterNodeLabelsRequestPBImpl;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.Collection;
+
+/**
+ * Remove label from cluster log store operation.
+ */
+public class RemoveClusterLabelOp
+    extends FSNodeStoreLogOp<CommonNodeLabelsManager> {
+
+  private Collection<String> labels;
+
+  public static final int OPCODE = 2;
+
+  @Override
+  public void write(OutputStream os, CommonNodeLabelsManager mgr)
+      throws IOException {
+    ((RemoveFromClusterNodeLabelsRequestPBImpl)
+        RemoveFromClusterNodeLabelsRequest
+        .newInstance(Sets.newHashSet(labels.iterator()))).getProto()
+        .writeDelimitedTo(os);
+  }
+
+  @Override
+  public void recover(InputStream is, CommonNodeLabelsManager mgr)
+      throws IOException {
+    labels =
+        YarnServerResourceManagerServiceProtos
+            .RemoveFromClusterNodeLabelsRequestProto
+            .parseDelimitedFrom(is).getNodeLabelsList();
+    mgr.removeFromClusterNodeLabels(labels);
+  }
+
+  public RemoveClusterLabelOp setLabels(Collection<String> labels) {
+    this.labels = labels;
+    return this;
+  }
+
+  public Collection<String> getLabels() {
+    return labels;
+  }
+
+  @Override
+  public int getOpCode() {
+    return OPCODE;
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/store/package-info.java

@@ -0,0 +1,21 @@
+/*
+ * 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.
+ */
+@InterfaceAudience.Private
+package org.apache.hadoop.yarn.nodelabels.store;
+import org.apache.hadoop.classification.InterfaceAudience;
+

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/server/api/protocolrecords/impl/pb/RemoveFromClusterNodeLabelsRequestPBImpl.java

@@ -6,9 +6,9 @@
  * 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
- *
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
  * 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.
@@ -21,12 +21,15 @@ package org.apache.hadoop.yarn.server.api.protocolrecords.impl.pb;
 import java.util.HashSet;
 import java.util.Set;
 
-import org.apache.hadoop.yarn.proto.YarnServerResourceManagerServiceProtos.RemoveFromClusterNodeLabelsRequestProtoOrBuilder;
-import org.apache.hadoop.yarn.proto.YarnServerResourceManagerServiceProtos.RemoveFromClusterNodeLabelsRequestProto;
-import org.apache.hadoop.yarn.server.api.protocolrecords.RemoveFromClusterNodeLabelsRequest;
+import org.apache.hadoop.yarn.proto.YarnServerResourceManagerServiceProtos
+    .RemoveFromClusterNodeLabelsRequestProtoOrBuilder;
+import org.apache.hadoop.yarn.proto.YarnServerResourceManagerServiceProtos
+    .RemoveFromClusterNodeLabelsRequestProto;
+import org.apache.hadoop.yarn.server.api.protocolrecords
+    .RemoveFromClusterNodeLabelsRequest;
 
-public class RemoveFromClusterNodeLabelsRequestPBImpl extends
-    RemoveFromClusterNodeLabelsRequest {
+public class RemoveFromClusterNodeLabelsRequestPBImpl
+    extends RemoveFromClusterNodeLabelsRequest {
   Set<String> labels;
   RemoveFromClusterNodeLabelsRequestProto proto =
       RemoveFromClusterNodeLabelsRequestProto.getDefaultInstance();
@@ -102,7 +105,7 @@ public class RemoveFromClusterNodeLabelsRequestPBImpl extends
     assert false : "hashCode not designed";
     return 0;
   }
-  
+
   @Override
   public boolean equals(Object other) {
     if (other == null)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/test/java/org/apache/hadoop/yarn/nodelabels/DummyCommonNodeLabelsManager.java

@@ -43,6 +43,12 @@ public class DummyCommonNodeLabelsManager extends CommonNodeLabelsManager {
           throws IOException {
       }
 
+      @Override
+      public void init(Configuration conf, CommonNodeLabelsManager mgr)
+          throws Exception {
+
+      }
+
       @Override
       public void removeClusterNodeLabels(Collection<String> labels)
           throws IOException {
@@ -65,8 +71,6 @@ public class DummyCommonNodeLabelsManager extends CommonNodeLabelsManager {
         // do nothing 
       }
     };
-
-    this.store.setNodeLabelsManager(this);
   }
 
   @Override

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/test/java/org/apache/hadoop/yarn/nodelabels/TestFileSystemNodeLabelsStore.java

@@ -96,7 +96,7 @@ public class TestFileSystemNodeLabelsStore extends NodeLabelTestBase {
     if (mgr.store instanceof FileSystemNodeLabelsStore) {
       FileSystemNodeLabelsStore fsStore =
           ((FileSystemNodeLabelsStore) mgr.store);
-      fsStore.fs.delete(fsStore.fsWorkingPath, true);
+      fsStore.getFs().delete(fsStore.getFsWorkingPath(), true);
     }
     mgr.stop();
   }
@@ -342,12 +342,12 @@ public class TestFileSystemNodeLabelsStore extends NodeLabelTestBase {
   public void testRootMkdirOnInitStore() throws Exception {
     final FileSystem mockFs = Mockito.mock(FileSystem.class);
     FileSystemNodeLabelsStore mockStore = new FileSystemNodeLabelsStore() {
-      void setFileSystem(Configuration conf) throws IOException {
-        fs = mockFs;
+      public void initFileSystem(Configuration config) throws IOException {
+        setFs(mockFs);
       }
     };
-    mockStore.setNodeLabelsManager(mgr);
-    mockStore.fs = mockFs;
+
+    mockStore.setFs(mockFs);
     verifyMkdirsCount(mockStore, true, 1);
     verifyMkdirsCount(mockStore, false, 2);
     verifyMkdirsCount(mockStore, true, 3);
@@ -357,10 +357,10 @@ public class TestFileSystemNodeLabelsStore extends NodeLabelTestBase {
   private void verifyMkdirsCount(FileSystemNodeLabelsStore store,
                                  boolean existsRetVal, int expectedNumOfCalls)
       throws Exception {
-    Mockito.when(store.fs.exists(Mockito.any(
+    Mockito.when(store.getFs().exists(Mockito.any(
         Path.class))).thenReturn(existsRetVal);
-    store.init(conf);
-    Mockito.verify(store.fs,Mockito.times(
+    store.init(conf, mgr);
+    Mockito.verify(store.getFs(),Mockito.times(
         expectedNumOfCalls)).mkdirs(Mockito.any(Path
         .class));
   }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/nodelabels/NullRMNodeLabelsManager.java

@@ -28,6 +28,7 @@ import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.yarn.api.records.NodeId;
 import org.apache.hadoop.yarn.api.records.NodeLabel;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
+import org.apache.hadoop.yarn.nodelabels.CommonNodeLabelsManager;
 import org.apache.hadoop.yarn.nodelabels.NodeLabelsStore;
 
 public class NullRMNodeLabelsManager extends RMNodeLabelsManager {
@@ -45,6 +46,12 @@ public class NullRMNodeLabelsManager extends RMNodeLabelsManager {
         // do nothing
       }
 
+      @Override
+      public void init(Configuration conf, CommonNodeLabelsManager mgr)
+          throws Exception {
+
+      }
+
       @Override
       public void removeClusterNodeLabels(Collection<String> labels)
           throws IOException {

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/TestRMWebServicesNodeLabels.java

@@ -605,7 +605,7 @@ public class TestRMWebServicesNodeLabels extends JerseyTestBase {
     String expectedmessage =
         "java.io.IOException: label name should only contains"
             + " {0-9, a-z, A-Z, -, _} and should not started with"
-            + " {-,_}, now it is=a&";
+            + " {-,_}, now it is= a&";
     validateJsonExceptionContent(response, expectedmessage);
   }