HBASE-5688 Convert zk root-region-server znode content to pb

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1308560 13f79535-47bb-0310-9956-ffa450edef68

src/main/java/org/apache/hadoop/hbase/catalog/RootLocationEditor.java

@@ -1,74 +0,0 @@
-/**
- * Copyright 2010 The Apache Software Foundation
- *
- * 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.hbase.catalog;
-
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-import org.apache.hadoop.classification.InterfaceAudience;
-import org.apache.hadoop.hbase.ServerName;
-import org.apache.hadoop.hbase.util.Bytes;
-import org.apache.hadoop.hbase.zookeeper.ZKUtil;
-import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
-import org.apache.zookeeper.KeeperException;
-
-/**
- * Makes changes to the location of <code>-ROOT-</code> in ZooKeeper.
- */
-@InterfaceAudience.Private
-public class RootLocationEditor {
-  private static final Log LOG = LogFactory.getLog(RootLocationEditor.class);
-
-  /**
-   * Deletes the location of <code>-ROOT-</code> in ZooKeeper.
-   * @param zookeeper zookeeper reference
-   * @throws KeeperException unexpected zookeeper exception
-   */
-  public static void deleteRootLocation(ZooKeeperWatcher zookeeper)
-  throws KeeperException {
-    LOG.info("Unsetting ROOT region location in ZooKeeper");
-    try {
-      // Just delete the node.  Don't need any watches, only we will create it.
-      ZKUtil.deleteNode(zookeeper, zookeeper.rootServerZNode);
-    } catch(KeeperException.NoNodeException nne) {
-      // Has already been deleted
-    }
-  }
-
-  /**
-   * Sets the location of <code>-ROOT-</code> in ZooKeeper to the
-   * specified server address.
-   * @param zookeeper zookeeper reference
-   * @param location The server hosting <code>-ROOT-</code>
-   * @throws KeeperException unexpected zookeeper exception
-   */
-  public static void setRootLocation(ZooKeeperWatcher zookeeper,
-      final ServerName location)
-  throws KeeperException {
-    LOG.info("Setting ROOT region location in ZooKeeper as " + location);
-    try {
-      ZKUtil.createAndWatch(zookeeper, zookeeper.rootServerZNode,
-        Bytes.toBytes(location.toString()));
-    } catch(KeeperException.NodeExistsException nee) {
-      LOG.debug("ROOT region location already existed, updated location");
-      ZKUtil.setData(zookeeper, zookeeper.rootServerZNode,
-          Bytes.toBytes(location.toString()));
-    }
-  }
-}

src/main/java/org/apache/hadoop/hbase/client/HConnectionManager.java

@@ -24,7 +24,6 @@ import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.hbase.Abortable;
 import org.apache.hadoop.hbase.Chore;
 import org.apache.hadoop.hbase.DoNotRetryIOException;
 import org.apache.hadoop.hbase.HBaseConfiguration;
@@ -920,10 +919,8 @@ public class HConnectionManager {
         try {
           LOG.debug("Looking up root region location in ZK," +
             " connection=" + this);
-          ServerName servername = RootRegionTracker.dataToServerName(
+          ServerName servername =
-            ZKUtil.blockUntilAvailable(
+            RootRegionTracker.blockUntilAvailable(zkw, this.rpcTimeout);
-              zkw, zkw.rootServerZNode, this.rpcTimeout)
-          );
 
           LOG.debug("Looked up root region location, connection=" + this +
             "; serverName=" + ((servername == null) ? "null" : servername));

src/main/java/org/apache/hadoop/hbase/master/AssignmentManager.java

@@ -58,7 +58,6 @@ import org.apache.hadoop.hbase.Stoppable;
 import org.apache.hadoop.hbase.TableNotFoundException;
 import org.apache.hadoop.hbase.catalog.CatalogTracker;
 import org.apache.hadoop.hbase.catalog.MetaReader;
-import org.apache.hadoop.hbase.catalog.RootLocationEditor;
 import org.apache.hadoop.hbase.client.Result;
 import org.apache.hadoop.hbase.executor.EventHandler;
 import org.apache.hadoop.hbase.executor.EventHandler.EventType;
@@ -79,6 +78,7 @@ import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.Pair;
 import org.apache.hadoop.hbase.util.Threads;
 import org.apache.hadoop.hbase.util.Writables;
+import org.apache.hadoop.hbase.zookeeper.RootRegionTracker;
 import org.apache.hadoop.hbase.zookeeper.ZKAssign;
 import org.apache.hadoop.hbase.zookeeper.ZKTable;
 import org.apache.hadoop.hbase.zookeeper.ZKUtil;
@@ -2151,7 +2151,7 @@ public class AssignmentManager extends ZooKeeperListener {
    * @throws KeeperException
    */
   public void assignRoot() throws KeeperException {
-    RootLocationEditor.deleteRootLocation(this.master.getZooKeeper());
+    RootRegionTracker.deleteRootLocation(this.master.getZooKeeper());
     assign(HRegionInfo.ROOT_REGIONINFO, true);
   }
 

src/main/java/org/apache/hadoop/hbase/protobuf/ProtobufUtil.java

@@ -0,0 +1,59 @@
+/**
+ * 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.hbase.protobuf;
+
+import org.apache.hadoop.hbase.util.Bytes;
+
+/**
+ * Protobufs utility.
+ */
+public class ProtobufUtil {
+  /**
+   * Magic we put ahead of a serialized protobuf message.
+   * For example, all znode content is protobuf messages with the below magic
+   * for preamble.
+   */
+  static final byte [] PB_MAGIC = new byte [] {'P', 'B', 'U', 'F'};
+
+  /**
+   * Prepend the passed bytes with four bytes of magic, {@link #PB_MAGIC}, to flag what
+   * follows as a protobuf in hbase.  Prepend these bytes to all content written to znodes, etc.
+   * @param bytes Bytes to decorate
+   * @return The passed <code>bytes</codes> with magic prepended (Creates a new
+   * byte array that is <code>bytes.length</code> plus {@link #PB_MAGIC}.length.
+   */
+  public static byte [] prependPBMagic(final byte [] bytes) {
+    return Bytes.add(PB_MAGIC, bytes);
+  }
+
+  /**
+   * @param bytes Bytes to check.
+   * @return True if passed <code>bytes</code> has {@link #PB_MAGIC} for a prefix.
+   */
+  public static boolean isPBMagicPrefix(final byte [] bytes) {
+    if (bytes == null || bytes.length <= PB_MAGIC.length) return false;
+    return Bytes.compareTo(PB_MAGIC, 0, PB_MAGIC.length, bytes, 0, PB_MAGIC.length) == 0;
+  }
+
+  /**
+   * @return Length of {@link #PB_MAGIC}
+   */
+  public static int lengthOfPBMagic() {
+    return PB_MAGIC.length;
+  }
+}

src/main/java/org/apache/hadoop/hbase/protobuf/generated/ZooKeeperProtos.java

@@ -0,0 +1,527 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: ZooKeeper.proto
+
+package org.apache.hadoop.hbase.protobuf.generated;
+
+public final class ZooKeeperProtos {
+  private ZooKeeperProtos() {}
+  public static void registerAllExtensions(
+      com.google.protobuf.ExtensionRegistry registry) {
+  }
+  public interface RootRegionServerOrBuilder
+      extends com.google.protobuf.MessageOrBuilder {
+    
+    // required .ServerName server = 2;
+    boolean hasServer();
+    org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName getServer();
+    org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerNameOrBuilder getServerOrBuilder();
+  }
+  public static final class RootRegionServer extends
+      com.google.protobuf.GeneratedMessage
+      implements RootRegionServerOrBuilder {
+    // Use RootRegionServer.newBuilder() to construct.
+    private RootRegionServer(Builder builder) {
+      super(builder);
+    }
+    private RootRegionServer(boolean noInit) {}
+    
+    private static final RootRegionServer defaultInstance;
+    public static RootRegionServer getDefaultInstance() {
+      return defaultInstance;
+    }
+    
+    public RootRegionServer getDefaultInstanceForType() {
+      return defaultInstance;
+    }
+    
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.internal_static_RootRegionServer_descriptor;
+    }
+    
+    protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.internal_static_RootRegionServer_fieldAccessorTable;
+    }
+    
+    private int bitField0_;
+    // required .ServerName server = 2;
+    public static final int SERVER_FIELD_NUMBER = 2;
+    private org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName server_;
+    public boolean hasServer() {
+      return ((bitField0_ & 0x00000001) == 0x00000001);
+    }
+    public org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName getServer() {
+      return server_;
+    }
+    public org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerNameOrBuilder getServerOrBuilder() {
+      return server_;
+    }
+    
+    private void initFields() {
+      server_ = org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName.getDefaultInstance();
+    }
+    private byte memoizedIsInitialized = -1;
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized != -1) return isInitialized == 1;
+      
+      if (!hasServer()) {
+        memoizedIsInitialized = 0;
+        return false;
+      }
+      if (!getServer().isInitialized()) {
+        memoizedIsInitialized = 0;
+        return false;
+      }
+      memoizedIsInitialized = 1;
+      return true;
+    }
+    
+    public void writeTo(com.google.protobuf.CodedOutputStream output)
+                        throws java.io.IOException {
+      getSerializedSize();
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        output.writeMessage(2, server_);
+      }
+      getUnknownFields().writeTo(output);
+    }
+    
+    private int memoizedSerializedSize = -1;
+    public int getSerializedSize() {
+      int size = memoizedSerializedSize;
+      if (size != -1) return size;
+    
+      size = 0;
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeMessageSize(2, server_);
+      }
+      size += getUnknownFields().getSerializedSize();
+      memoizedSerializedSize = size;
+      return size;
+    }
+    
+    private static final long serialVersionUID = 0L;
+    @java.lang.Override
+    protected java.lang.Object writeReplace()
+        throws java.io.ObjectStreamException {
+      return super.writeReplace();
+    }
+    
+    @java.lang.Override
+    public boolean equals(final java.lang.Object obj) {
+      if (obj == this) {
+       return true;
+      }
+      if (!(obj instanceof org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer)) {
+        return super.equals(obj);
+      }
+      org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer other = (org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer) obj;
+      
+      boolean result = true;
+      result = result && (hasServer() == other.hasServer());
+      if (hasServer()) {
+        result = result && getServer()
+            .equals(other.getServer());
+      }
+      result = result &&
+          getUnknownFields().equals(other.getUnknownFields());
+      return result;
+    }
+    
+    @java.lang.Override
+    public int hashCode() {
+      int hash = 41;
+      hash = (19 * hash) + getDescriptorForType().hashCode();
+      if (hasServer()) {
+        hash = (37 * hash) + SERVER_FIELD_NUMBER;
+        hash = (53 * hash) + getServer().hashCode();
+      }
+      hash = (29 * hash) + getUnknownFields().hashCode();
+      return hash;
+    }
+    
+    public static org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer parseFrom(
+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data).buildParsed();
+    }
+    public static org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data).buildParsed();
+    }
+    public static org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input).buildParsed();
+    }
+    public static org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      Builder builder = newBuilder();
+      if (builder.mergeDelimitedFrom(input)) {
+        return builder.buildParsed();
+      } else {
+        return null;
+      }
+    }
+    public static org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      Builder builder = newBuilder();
+      if (builder.mergeDelimitedFrom(input, extensionRegistry)) {
+        return builder.buildParsed();
+      } else {
+        return null;
+      }
+    }
+    public static org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input).buildParsed();
+    }
+    public static org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input, extensionRegistry)
+               .buildParsed();
+    }
+    
+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer prototype) {
+      return newBuilder().mergeFrom(prototype);
+    }
+    public Builder toBuilder() { return newBuilder(this); }
+    
+    @java.lang.Override
+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+      Builder builder = new Builder(parent);
+      return builder;
+    }
+    public static final class Builder extends
+        com.google.protobuf.GeneratedMessage.Builder<Builder>
+       implements org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServerOrBuilder {
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.internal_static_RootRegionServer_descriptor;
+      }
+      
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.internal_static_RootRegionServer_fieldAccessorTable;
+      }
+      
+      // Construct using org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer.newBuilder()
+      private Builder() {
+        maybeForceBuilderInitialization();
+      }
+      
+      private Builder(BuilderParent parent) {
+        super(parent);
+        maybeForceBuilderInitialization();
+      }
+      private void maybeForceBuilderInitialization() {
+        if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+          getServerFieldBuilder();
+        }
+      }
+      private static Builder create() {
+        return new Builder();
+      }
+      
+      public Builder clear() {
+        super.clear();
+        if (serverBuilder_ == null) {
+          server_ = org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName.getDefaultInstance();
+        } else {
+          serverBuilder_.clear();
+        }
+        bitField0_ = (bitField0_ & ~0x00000001);
+        return this;
+      }
+      
+      public Builder clone() {
+        return create().mergeFrom(buildPartial());
+      }
+      
+      public com.google.protobuf.Descriptors.Descriptor
+          getDescriptorForType() {
+        return org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer.getDescriptor();
+      }
+      
+      public org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer getDefaultInstanceForType() {
+        return org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer.getDefaultInstance();
+      }
+      
+      public org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer build() {
+        org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
+      }
+      
+      private org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer buildParsed()
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(
+            result).asInvalidProtocolBufferException();
+        }
+        return result;
+      }
+      
+      public org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer buildPartial() {
+        org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer result = new org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer(this);
+        int from_bitField0_ = bitField0_;
+        int to_bitField0_ = 0;
+        if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+          to_bitField0_ |= 0x00000001;
+        }
+        if (serverBuilder_ == null) {
+          result.server_ = server_;
+        } else {
+          result.server_ = serverBuilder_.build();
+        }
+        result.bitField0_ = to_bitField0_;
+        onBuilt();
+        return result;
+      }
+      
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer) {
+          return mergeFrom((org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer)other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+      
+      public Builder mergeFrom(org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer other) {
+        if (other == org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer.getDefaultInstance()) return this;
+        if (other.hasServer()) {
+          mergeServer(other.getServer());
+        }
+        this.mergeUnknownFields(other.getUnknownFields());
+        return this;
+      }
+      
+      public final boolean isInitialized() {
+        if (!hasServer()) {
+          
+          return false;
+        }
+        if (!getServer().isInitialized()) {
+          
+          return false;
+        }
+        return true;
+      }
+      
+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder(
+            this.getUnknownFields());
+        while (true) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              this.setUnknownFields(unknownFields.build());
+              onChanged();
+              return this;
+            default: {
+              if (!parseUnknownField(input, unknownFields,
+                                     extensionRegistry, tag)) {
+                this.setUnknownFields(unknownFields.build());
+                onChanged();
+                return this;
+              }
+              break;
+            }
+            case 18: {
+              org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName.Builder subBuilder = org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName.newBuilder();
+              if (hasServer()) {
+                subBuilder.mergeFrom(getServer());
+              }
+              input.readMessage(subBuilder, extensionRegistry);
+              setServer(subBuilder.buildPartial());
+              break;
+            }
+          }
+        }
+      }
+      
+      private int bitField0_;
+      
+      // required .ServerName server = 2;
+      private org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName server_ = org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName.getDefaultInstance();
+      private com.google.protobuf.SingleFieldBuilder<
+          org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName, org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName.Builder, org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerNameOrBuilder> serverBuilder_;
+      public boolean hasServer() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      public org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName getServer() {
+        if (serverBuilder_ == null) {
+          return server_;
+        } else {
+          return serverBuilder_.getMessage();
+        }
+      }
+      public Builder setServer(org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName value) {
+        if (serverBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          server_ = value;
+          onChanged();
+        } else {
+          serverBuilder_.setMessage(value);
+        }
+        bitField0_ |= 0x00000001;
+        return this;
+      }
+      public Builder setServer(
+          org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName.Builder builderForValue) {
+        if (serverBuilder_ == null) {
+          server_ = builderForValue.build();
+          onChanged();
+        } else {
+          serverBuilder_.setMessage(builderForValue.build());
+        }
+        bitField0_ |= 0x00000001;
+        return this;
+      }
+      public Builder mergeServer(org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName value) {
+        if (serverBuilder_ == null) {
+          if (((bitField0_ & 0x00000001) == 0x00000001) &&
+              server_ != org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName.getDefaultInstance()) {
+            server_ =
+              org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName.newBuilder(server_).mergeFrom(value).buildPartial();
+          } else {
+            server_ = value;
+          }
+          onChanged();
+        } else {
+          serverBuilder_.mergeFrom(value);
+        }
+        bitField0_ |= 0x00000001;
+        return this;
+      }
+      public Builder clearServer() {
+        if (serverBuilder_ == null) {
+          server_ = org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName.getDefaultInstance();
+          onChanged();
+        } else {
+          serverBuilder_.clear();
+        }
+        bitField0_ = (bitField0_ & ~0x00000001);
+        return this;
+      }
+      public org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName.Builder getServerBuilder() {
+        bitField0_ |= 0x00000001;
+        onChanged();
+        return getServerFieldBuilder().getBuilder();
+      }
+      public org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerNameOrBuilder getServerOrBuilder() {
+        if (serverBuilder_ != null) {
+          return serverBuilder_.getMessageOrBuilder();
+        } else {
+          return server_;
+        }
+      }
+      private com.google.protobuf.SingleFieldBuilder<
+          org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName, org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName.Builder, org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerNameOrBuilder> 
+          getServerFieldBuilder() {
+        if (serverBuilder_ == null) {
+          serverBuilder_ = new com.google.protobuf.SingleFieldBuilder<
+              org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName, org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName.Builder, org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerNameOrBuilder>(
+                  server_,
+                  getParentForChildren(),
+                  isClean());
+          server_ = null;
+        }
+        return serverBuilder_;
+      }
+      
+      // @@protoc_insertion_point(builder_scope:RootRegionServer)
+    }
+    
+    static {
+      defaultInstance = new RootRegionServer(true);
+      defaultInstance.initFields();
+    }
+    
+    // @@protoc_insertion_point(class_scope:RootRegionServer)
+  }
+  
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_RootRegionServer_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_RootRegionServer_fieldAccessorTable;
+  
+  public static com.google.protobuf.Descriptors.FileDescriptor
+      getDescriptor() {
+    return descriptor;
+  }
+  private static com.google.protobuf.Descriptors.FileDescriptor
+      descriptor;
+  static {
+    java.lang.String[] descriptorData = {
+      "\n\017ZooKeeper.proto\032\013hbase.proto\"/\n\020RootRe" +
+      "gionServer\022\033\n\006server\030\002 \002(\0132\013.ServerNameB" +
+      "E\n*org.apache.hadoop.hbase.protobuf.gene" +
+      "ratedB\017ZooKeeperProtosH\001\210\001\001\240\001\001"
+    };
+    com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner assigner =
+      new com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner() {
+        public com.google.protobuf.ExtensionRegistry assignDescriptors(
+            com.google.protobuf.Descriptors.FileDescriptor root) {
+          descriptor = root;
+          internal_static_RootRegionServer_descriptor =
+            getDescriptor().getMessageTypes().get(0);
+          internal_static_RootRegionServer_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_RootRegionServer_descriptor,
+              new java.lang.String[] { "Server", },
+              org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer.class,
+              org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer.Builder.class);
+          return null;
+        }
+      };
+    com.google.protobuf.Descriptors.FileDescriptor
+      .internalBuildGeneratedFileFrom(descriptorData,
+        new com.google.protobuf.Descriptors.FileDescriptor[] {
+          org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.getDescriptor(),
+        }, assigner);
+  }
+  
+  // @@protoc_insertion_point(outer_class_scope)
+}

src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java

@@ -84,7 +84,6 @@ import org.apache.hadoop.hbase.YouAreDeadException;
 import org.apache.hadoop.hbase.catalog.CatalogTracker;
 import org.apache.hadoop.hbase.catalog.MetaEditor;
 import org.apache.hadoop.hbase.catalog.MetaReader;
-import org.apache.hadoop.hbase.catalog.RootLocationEditor;
 import org.apache.hadoop.hbase.client.Action;
 import org.apache.hadoop.hbase.client.Append;
 import org.apache.hadoop.hbase.client.Delete;
@@ -148,6 +147,7 @@ import org.apache.hadoop.hbase.util.Sleeper;
 import org.apache.hadoop.hbase.util.Threads;
 import org.apache.hadoop.hbase.util.VersionInfo;
 import org.apache.hadoop.hbase.zookeeper.ClusterStatusTracker;
+import org.apache.hadoop.hbase.zookeeper.RootRegionTracker;
 import org.apache.hadoop.hbase.zookeeper.SchemaChangeTracker;
 import org.apache.hadoop.hbase.zookeeper.ZKUtil;
 import org.apache.hadoop.hbase.zookeeper.ZooKeeperNodeTracker;
@@ -1634,7 +1634,7 @@ public class HRegionServer implements HRegionInterface, HBaseRPCErrorHandler,
     }
     // Update ZK, ROOT or META
     if (r.getRegionInfo().isRootRegion()) {
-      RootLocationEditor.setRootLocation(getZooKeeper(),
+      RootRegionTracker.setRootLocation(getZooKeeper(),
        this.serverNameFromMasterPOV);
     } else if (r.getRegionInfo().isMetaRegion()) {
       MetaEditor.updateMetaLocation(ct, r.getRegionInfo(),

src/main/java/org/apache/hadoop/hbase/util/HBaseFsck.java

@@ -1076,18 +1076,15 @@ public class HBaseFsck {
   }
 
   private ServerName getRootRegionServerName()
-    throws IOException, KeeperException {
+  throws IOException, KeeperException {
-
     ZooKeeperWatcher zkw = createZooKeeperWatcher();
-
+    ServerName sn = null;
-    byte[] data;
     try {
-      data = ZKUtil.getData(zkw, zkw.rootServerZNode);
+      sn = RootRegionTracker.getRootRegionLocation(zkw);
     } finally {
       zkw.close();
     }
-
+    return sn;
-    return RootRegionTracker.dataToServerName(data);
   }
 
   /**

src/main/java/org/apache/hadoop/hbase/zookeeper/RootRegionTracker.java

@@ -1,6 +1,4 @@
 /**
- * Copyright 2010 The Apache Software Foundation
- *
  * 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
@@ -22,9 +20,15 @@ package org.apache.hadoop.hbase.zookeeper;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.Abortable;
 import org.apache.hadoop.hbase.ServerName;
-import org.apache.hadoop.hbase.catalog.RootLocationEditor;
+import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos;
+import org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos;
+import org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer;
 import org.apache.hadoop.hbase.util.Addressing;
 import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.zookeeper.KeeperException;
+
+import com.google.protobuf.InvalidProtocolBufferException;
 
 /**
  * Tracks the root region server location node in zookeeper.
@@ -55,14 +59,26 @@ public class RootRegionTracker extends ZooKeeperNodeTracker {
   }
 
   /**
-   * Gets the root region location, if available.  Null if not.  Does not block.
+   * Gets the root region location, if available.  Does not block.  Sets a watcher.
-   * @return server name
+   * @return server name or null if we failed to get the data.
    * @throws InterruptedException
    */
   public ServerName getRootRegionLocation() throws InterruptedException {
     return dataToServerName(super.getData(true));
   }
 
+  /**
+   * Gets the root region location, if available.  Does not block.  Does not set
+   * a watcher (In this regard it differs from {@link #getRootRegionLocation()}.
+   * @param zkw
+   * @return server name or null if we failed to get the data.
+   * @throws KeeperException
+   */
+  public static ServerName getRootRegionLocation(final ZooKeeperWatcher zkw)
+  throws KeeperException {
+    return dataToServerName(ZKUtil.getData(zkw, zkw.rootServerZNode));
+  }
+
   /**
    * Gets the root region location, if available, and waits for up to the
    * specified timeout if not immediately available.
@@ -84,16 +100,98 @@ public class RootRegionTracker extends ZooKeeperNodeTracker {
     return dataToServerName(super.blockUntilAvailable(timeout, true));
   }
 
-  /*
+  /**
+   * Sets the location of <code>-ROOT-</code> in ZooKeeper to the
+   * specified server address.
+   * @param zookeeper zookeeper reference
+   * @param location The server hosting <code>-ROOT-</code>
+   * @throws KeeperException unexpected zookeeper exception
+   */
+  public static void setRootLocation(ZooKeeperWatcher zookeeper,
+      final ServerName location)
+  throws KeeperException {
+    LOG.info("Setting ROOT region location in ZooKeeper as " + location);
+    // Make the RootRegionServer pb and then get its bytes and save this as
+    // the znode content.
+    byte [] data = getRootRegionServerZNodeContent(location);
+    try {
+      ZKUtil.createAndWatch(zookeeper, zookeeper.rootServerZNode, data);
+    } catch(KeeperException.NodeExistsException nee) {
+      LOG.debug("ROOT region location already existed, updated location");
+      ZKUtil.setData(zookeeper, zookeeper.rootServerZNode, data);
+    }
+  }
+
+  /**
+   * Build up the znode content.
+   * @param sn What to put into the znode.
+   * @return The content of the root-region-server znode
+   */
+  static byte [] getRootRegionServerZNodeContent(final ServerName sn) {
+    // ZNode content is a pb message preceeded by some pb magic.
+    HBaseProtos.ServerName pbsn =
+      HBaseProtos.ServerName.newBuilder().setHostName(sn.getHostname()).
+      setPort(sn.getPort()).setStartCode(sn.getStartcode()).build();
+    ZooKeeperProtos.RootRegionServer pbrsr =
+      ZooKeeperProtos.RootRegionServer.newBuilder().setServer(pbsn).build();
+    return ProtobufUtil.prependPBMagic(pbrsr.toByteArray());
+  }
+
+  /**
+   * Deletes the location of <code>-ROOT-</code> in ZooKeeper.
+   * @param zookeeper zookeeper reference
+   * @throws KeeperException unexpected zookeeper exception
+   */
+  public static void deleteRootLocation(ZooKeeperWatcher zookeeper)
+  throws KeeperException {
+    LOG.info("Unsetting ROOT region location in ZooKeeper");
+    try {
+      // Just delete the node.  Don't need any watches.
+      ZKUtil.deleteNode(zookeeper, zookeeper.rootServerZNode);
+    } catch(KeeperException.NoNodeException nne) {
+      // Has already been deleted
+    }
+  }
+
+  /**
+   * Wait until the root region is available.
+   * @param zkw
+   * @param timeout
+   * @return ServerName or null if we timed out.
+   * @throws InterruptedException
+   */
+  public static ServerName blockUntilAvailable(final ZooKeeperWatcher zkw,
+      final long timeout)
+  throws InterruptedException {
+    byte [] data = ZKUtil.blockUntilAvailable(zkw, zkw.rootServerZNode, timeout);
+    return dataToServerName(data);
+  }
+
+  /**
    * @param data
    * @return Returns null if <code>data</code> is null else converts passed data
    * to a ServerName instance.
    */
-  public static ServerName dataToServerName(final byte [] data) {
+  static ServerName dataToServerName(final byte [] data) {
+    if (data == null || data.length <= 0) return null;
+    if (ProtobufUtil.isPBMagicPrefix(data)) {
+      int prefixLen = ProtobufUtil.lengthOfPBMagic();
+      try {
+        RootRegionServer rss =
+          RootRegionServer.newBuilder().mergeFrom(data, prefixLen, data.length - prefixLen).build();
+        HBaseProtos.ServerName sn = rss.getServer();
+        return new ServerName(sn.getHostName(), sn.getPort(), sn.getStartCode());
+      } catch (InvalidProtocolBufferException e) {
+        // A failed parse of the znode is pretty catastrophic. Rather than loop
+        // retrying hoping the bad bytes will changes, and rather than change
+        // the signature on this method to add an IOE which will send ripples all
+        // over the code base, throw a RuntimeException.  This should "never" happen.
+        throw new RuntimeException(e);
+      }
+    }
     // The str returned could be old style -- pre hbase-1502 -- which was
     // hostname and port seperated by a colon rather than hostname, port and
     // startcode delimited by a ','.
-    if (data == null || data.length <= 0) return null;
     String str = Bytes.toString(data);
     int index = str.indexOf(ServerName.SERVERNAME_SEPARATOR);
     if (index != -1) {

src/main/protobuf/ZooKeeper.proto

@@ -0,0 +1,36 @@
+/**
+ * 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.
+ */
+
+// ZNode data in hbase are serialized protobufs with a four byte
+// 'magic' 'PBUF' prefix.
+
+option java_package = "org.apache.hadoop.hbase.protobuf.generated";
+option java_outer_classname = "ZooKeeperProtos";
+option java_generic_services = true;
+option java_generate_equals_and_hash = true;
+option optimize_for = SPEED;
+
+import "hbase.proto";
+
+/**
+ * Content of the root-region-server znode.
+ */
+message RootRegionServer {
+  // The ServerName hosting the root region currently.
+  required ServerName server = 1;
+}

src/test/java/org/apache/hadoop/hbase/catalog/TestCatalogTracker.java

@@ -44,6 +44,7 @@ import org.apache.hadoop.hbase.ipc.HRegionInterface;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.Threads;
 import org.apache.hadoop.hbase.util.Writables;
+import org.apache.hadoop.hbase.zookeeper.RootRegionTracker;
 import org.apache.hadoop.hbase.zookeeper.ZKUtil;
 import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
 import org.apache.hadoop.util.Progressable;
@@ -118,12 +119,12 @@ public class TestCatalogTracker {
     HConnection connection = Mockito.mock(HConnection.class);
     constructAndStartCatalogTracker(connection);
     try {
-      RootLocationEditor.setRootLocation(this.watcher,
+      RootRegionTracker.setRootLocation(this.watcher,
         new ServerName("example.com", 1234, System.currentTimeMillis()));
     } finally {
       // Clean out root location or later tests will be confused... they presume
       // start fresh in zk.
-      RootLocationEditor.deleteRootLocation(this.watcher);
+      RootRegionTracker.deleteRootLocation(this.watcher);
     }
   }
 
@@ -201,7 +202,7 @@ public class TestCatalogTracker {
       final CatalogTracker ct = constructAndStartCatalogTracker(connection);
       try {
         // Set a location for root and meta.
-        RootLocationEditor.setRootLocation(this.watcher, SN);
+        RootRegionTracker.setRootLocation(this.watcher, SN);
         ct.setMetaLocation(SN);
         // Call the method that HBASE-4288 calls.  It will try and verify the
         // meta location and will fail on first attempt then go into a long wait.
@@ -231,7 +232,7 @@ public class TestCatalogTracker {
         // Clean out root and meta locations or later tests will be confused...
         // they presume start fresh in zk.
         ct.resetMetaLocation();
-        RootLocationEditor.deleteRootLocation(this.watcher);
+        RootRegionTracker.deleteRootLocation(this.watcher);
       }
     } finally {
       // Clear out our doctored connection or could mess up subsequent tests.
@@ -258,14 +259,14 @@ public class TestCatalogTracker {
       // Now start up the catalogtracker with our doctored Connection.
       final CatalogTracker ct = constructAndStartCatalogTracker(connection);
       try {
-        RootLocationEditor.setRootLocation(this.watcher, SN);
+        RootRegionTracker.setRootLocation(this.watcher, SN);
         long timeout = UTIL.getConfiguration().
           getLong("hbase.catalog.verification.timeout", 1000);
         Assert.assertFalse(ct.verifyMetaRegionLocation(timeout));
       } finally {
         // Clean out root location or later tests will be confused... they
         // presume start fresh in zk.
-        RootLocationEditor.deleteRootLocation(this.watcher);
+        RootRegionTracker.deleteRootLocation(this.watcher);
       }
     } finally {
       // Clear out our doctored connection or could mess up subsequent tests.
@@ -294,13 +295,13 @@ public class TestCatalogTracker {
       thenReturn(implementation);
     final CatalogTracker ct = constructAndStartCatalogTracker(connection);
     try {
-      RootLocationEditor.setRootLocation(this.watcher,
+      RootRegionTracker.setRootLocation(this.watcher,
         new ServerName("example.com", 1234, System.currentTimeMillis()));
       Assert.assertFalse(ct.verifyRootRegionLocation(100));
     } finally {
       // Clean out root location or later tests will be confused... they presume
       // start fresh in zk.
-      RootLocationEditor.deleteRootLocation(this.watcher);
+      RootRegionTracker.deleteRootLocation(this.watcher);
     }
   }
 
@@ -350,7 +351,7 @@ public class TestCatalogTracker {
   }
 
   private ServerName setRootLocation() throws KeeperException {
-    RootLocationEditor.setRootLocation(this.watcher, SN);
+    RootRegionTracker.setRootLocation(this.watcher, SN);
     return SN;
   }
 

src/test/java/org/apache/hadoop/hbase/catalog/TestCatalogTrackerOnCluster.java

@@ -22,6 +22,7 @@ package org.apache.hadoop.hbase.catalog;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.hbase.*;
+import org.apache.hadoop.hbase.zookeeper.RootRegionTracker;
 import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
 import org.apache.zookeeper.KeeperException;
 import org.junit.Test;
@@ -61,7 +62,7 @@ public class TestCatalogTrackerOnCluster {
     });
     ServerName nonsense =
       new ServerName("example.org", 1234, System.currentTimeMillis());
-    RootLocationEditor.setRootLocation(zookeeper, nonsense);
+    RootRegionTracker.setRootLocation(zookeeper, nonsense);
 
     // Bring back up the hbase cluster.  See if it can deal with nonsense root
     // location. The cluster should start and be fully available.

src/test/java/org/apache/hadoop/hbase/master/TestMasterNoCluster.java

@@ -35,13 +35,13 @@ import org.apache.hadoop.hbase.Server;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.ZooKeeperConnectionException;
 import org.apache.hadoop.hbase.catalog.CatalogTracker;
-import org.apache.hadoop.hbase.catalog.RootLocationEditor;
 import org.apache.hadoop.hbase.client.HConnection;
 import org.apache.hadoop.hbase.client.HConnectionTestingUtility;
 import org.apache.hadoop.hbase.client.Result;
 import org.apache.hadoop.hbase.regionserver.RegionOpeningState;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.Threads;
+import org.apache.hadoop.hbase.zookeeper.RootRegionTracker;
 import org.apache.hadoop.hbase.zookeeper.ZKUtil;
 import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
 import org.apache.hadoop.io.MapWritable;
@@ -139,7 +139,7 @@ public class TestMasterNoCluster {
     // Put some data into the servers.  Make it look like sn0 has the root
     // w/ an entry that points to sn1 as the host of .META.  Put data into sn2
     // so it looks like it has a few regions for a table named 't'.
-    RootLocationEditor.setRootLocation(rs0.getZooKeeper(), rs0.getServerName());
+    RootRegionTracker.setRootLocation(rs0.getZooKeeper(), rs0.getServerName());
     byte [] rootregion = Bytes.toBytes("-ROOT-,,0");
     rs0.setGetResult(rootregion, HRegionInfo.FIRST_META_REGIONINFO.getRegionName(),
       Mocking.getMetaTableRowResult(HRegionInfo.FIRST_META_REGIONINFO,
@@ -300,7 +300,7 @@ public class TestMasterNoCluster {
       // when its figured it just opened the root region by setting the root
       // location up into zk.  Since we're mocking regionserver, need to do this
       // ourselves.
-      RootLocationEditor.setRootLocation(rs0.getZooKeeper(), rs0.getServerName());
+      RootRegionTracker.setRootLocation(rs0.getZooKeeper(), rs0.getServerName());
       // Do same transitions for .META. (presuming master has by now assigned
       // .META. to rs1).
       Mocking.fakeRegionServerRegionOpenInZK(rs0.getZooKeeper(),