/**
* 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.protocol.FSConstants.UpgradeAction;
import org.apache.hadoop.hdfs.server.common.HdfsConstants;
import org.apache.hadoop.hdfs.server.common.IncorrectVersionException;
import org.apache.hadoop.hdfs.server.common.UpgradeManager;
import org.apache.hadoop.hdfs.server.common.UpgradeStatusReport;
import org.apache.hadoop.hdfs.server.protocol.UpgradeCommand;
/**
* Upgrade manager for name-nodes.
*
* Distributed upgrades for a name-node starts when the safe mode conditions
* are met and the name-node is about to exit it.
* At this point the name-node enters manual safe mode which will remain
* on until the upgrade is completed.
* After that the name-nodes processes upgrade commands from data-nodes
* and updates its status.
*/
class UpgradeManagerNamenode extends UpgradeManager {
public HdfsConstants.NodeType getType() {
return HdfsConstants.NodeType.NAME_NODE;
}
private final FSNamesystem namesystem;
UpgradeManagerNamenode(FSNamesystem namesystem) {
this.namesystem = namesystem;
}
/**
* Start distributed upgrade.
* Instantiates distributed upgrade objects.
*
* @return true if distributed upgrade is required or false otherwise
* @throws IOException
*/
public synchronized boolean startUpgrade() throws IOException {
if(!upgradeState) {
initializeUpgrade();
if(!upgradeState) return false;
// write new upgrade state into disk
namesystem.getFSImage().writeAll();
}
assert currentUpgrades != null : "currentUpgrades is null";
this.broadcastCommand = currentUpgrades.first().startUpgrade();
NameNode.LOG.info("\n Distributed upgrade for NameNode version "
+ getUpgradeVersion() + " to current LV "
+ FSConstants.LAYOUT_VERSION + " is started.");
return true;
}
synchronized UpgradeCommand processUpgradeCommand(UpgradeCommand command
) throws IOException {
NameNode.LOG.debug("\n Distributed upgrade for NameNode version "
+ getUpgradeVersion() + " to current LV "
+ FSConstants.LAYOUT_VERSION + " is processing upgrade command: "
+ command.getAction() + " status = " + getUpgradeStatus() + "%");
if(currentUpgrades == null) {
NameNode.LOG.info("Ignoring upgrade command: "
+ command.getAction() + " version " + command.getVersion()
+ ". No distributed upgrades are currently running on the NameNode");
return null;
}
UpgradeObjectNamenode curUO = (UpgradeObjectNamenode)currentUpgrades.first();
if(command.getVersion() != curUO.getVersion())
throw new IncorrectVersionException(command.getVersion(),
"UpgradeCommand", curUO.getVersion());
UpgradeCommand reply = curUO.processUpgradeCommand(command);
if(curUO.getUpgradeStatus() < 100) {
return reply;
}
// current upgrade is done
curUO.completeUpgrade();
NameNode.LOG.info("\n Distributed upgrade for NameNode version "
+ curUO.getVersion() + " to current LV "
+ FSConstants.LAYOUT_VERSION + " is complete.");
// proceede with the next one
currentUpgrades.remove(curUO);
if(currentUpgrades.isEmpty()) { // all upgrades are done
completeUpgrade();
} else { // start next upgrade
curUO = (UpgradeObjectNamenode)currentUpgrades.first();
this.broadcastCommand = curUO.startUpgrade();
}
return reply;
}
public synchronized void completeUpgrade() throws IOException {
// set and write new upgrade state into disk
setUpgradeState(false, FSConstants.LAYOUT_VERSION);
namesystem.getFSImage().writeAll();
currentUpgrades = null;
broadcastCommand = null;
namesystem.leaveSafeMode(false);
}
UpgradeStatusReport distributedUpgradeProgress(UpgradeAction action
) throws IOException {
boolean isFinalized = false;
if(currentUpgrades == null) { // no upgrades are in progress
FSImage fsimage = namesystem.getFSImage();
isFinalized = fsimage.isUpgradeFinalized();
if(isFinalized) // upgrade is finalized
return null; // nothing to report
return new UpgradeStatusReport(fsimage.getLayoutVersion(),
(short)101, isFinalized);
}
UpgradeObjectNamenode curUO = (UpgradeObjectNamenode)currentUpgrades.first();
boolean details = false;
switch(action) {
case GET_STATUS:
break;
case DETAILED_STATUS:
details = true;
break;
case FORCE_PROCEED:
curUO.forceProceed();
}
return curUO.getUpgradeStatusReport(details);
}
}