| /** |
| * 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.hdfs.server.namenode; |
| |
| import java.io.IOException; |
| |
| import org.apache.hadoop.hdfs.server.common.HdfsConstants; |
| import org.apache.hadoop.hdfs.server.common.UpgradeObject; |
| import org.apache.hadoop.hdfs.server.protocol.UpgradeCommand; |
| |
| /** |
| * Base class for name-node upgrade objects. |
| * Data-node upgrades are run in separate threads. |
| */ |
| public abstract class UpgradeObjectNamenode extends UpgradeObject { |
| |
| /** |
| * Process an upgrade command. |
| * RPC has only one very generic command for all upgrade related inter |
| * component communications. |
| * The actual command recognition and execution should be handled here. |
| * The reply is sent back also as an UpgradeCommand. |
| * |
| * @param command |
| * @return the reply command which is analyzed on the client side. |
| */ |
| public abstract UpgradeCommand processUpgradeCommand(UpgradeCommand command |
| ) throws IOException; |
| |
| public HdfsConstants.NodeType getType() { |
| return HdfsConstants.NodeType.NAME_NODE; |
| } |
| |
| /** |
| */ |
| public UpgradeCommand startUpgrade() throws IOException { |
| // broadcast that data-nodes must start the upgrade |
| return new UpgradeCommand(UpgradeCommand.UC_ACTION_START_UPGRADE, |
| getVersion(), (short)0); |
| } |
| |
| public void forceProceed() throws IOException { |
| // do nothing by default |
| NameNode.LOG.info("forceProceed() is not defined for the upgrade. " |
| + getDescription()); |
| } |
| } |