UpgradeObjectNamenode.java
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上传日期:2018-01-08
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文件大小:2k
- /**
- * 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.protocol.FSConstants;
- 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);
- }
- protected FSNamesystem getFSNamesystem() {
- return FSNamesystem.getFSNamesystem();
- }
- public void forceProceed() throws IOException {
- // do nothing by default
- NameNode.LOG.info("forceProceed() is not defined for the upgrade. "
- + getDescription());
- }
- }