| /** |
| * 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.blockmanagement; |
| |
| import java.util.Map; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.hdfs.server.namenode.Namesystem; |
| |
| /** |
| * Manage node decommissioning. |
| */ |
| @InterfaceAudience.Private |
| @InterfaceStability.Evolving |
| class DecommissionManager { |
| static final Log LOG = LogFactory.getLog(DecommissionManager.class); |
| |
| private final Namesystem namesystem; |
| private final BlockManager blockmanager; |
| |
| DecommissionManager(final Namesystem namesystem, |
| final BlockManager blockmanager) { |
| this.namesystem = namesystem; |
| this.blockmanager = blockmanager; |
| } |
| |
| /** Periodically check decommission status. */ |
| class Monitor implements Runnable { |
| /** recheckInterval is how often namenode checks |
| * if a node has finished decommission |
| */ |
| private final long recheckInterval; |
| /** The number of decommission nodes to check for each interval */ |
| private final int numNodesPerCheck; |
| /** firstkey can be initialized to anything. */ |
| private String firstkey = ""; |
| |
| Monitor(int recheckIntervalInSecond, int numNodesPerCheck) { |
| this.recheckInterval = recheckIntervalInSecond * 1000L; |
| this.numNodesPerCheck = numNodesPerCheck; |
| } |
| |
| /** |
| * Check decommission status of numNodesPerCheck nodes |
| * for every recheckInterval milliseconds. |
| */ |
| @Override |
| public void run() { |
| for(; namesystem.isRunning(); ) { |
| namesystem.writeLock(); |
| try { |
| check(); |
| } finally { |
| namesystem.writeUnlock(); |
| } |
| |
| try { |
| Thread.sleep(recheckInterval); |
| } catch (InterruptedException ie) { |
| LOG.warn(this.getClass().getSimpleName() + " interrupted: " + ie); |
| } |
| } |
| } |
| |
| private void check() { |
| final DatanodeManager dm = blockmanager.getDatanodeManager(); |
| int count = 0; |
| for(Map.Entry<String, DatanodeDescriptor> entry |
| : dm.getDatanodeCyclicIteration(firstkey)) { |
| final DatanodeDescriptor d = entry.getValue(); |
| firstkey = entry.getKey(); |
| |
| if (d.isDecommissionInProgress()) { |
| try { |
| dm.checkDecommissionState(d); |
| } catch(Exception e) { |
| LOG.warn("entry=" + entry, e); |
| } |
| if (++count == numNodesPerCheck) { |
| return; |
| } |
| } |
| } |
| } |
| } |
| } |