| /** |
| * 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; |
| |
| import static org.junit.Assert.assertEquals; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| |
| import org.apache.hadoop.fs.FSDataOutputStream; |
| import org.apache.hadoop.fs.FileSystem; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor; |
| import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeManager; |
| import org.junit.Test; |
| |
| /** |
| * This class tests DatanodeDescriptor.getBlocksScheduled() at the |
| * NameNode. This counter is supposed to keep track of blocks currently |
| * scheduled to a datanode. |
| */ |
| public class TestBlocksScheduledCounter { |
| |
| @Test |
| public void testBlocksScheduledCounter() throws IOException { |
| MiniDFSCluster cluster = new MiniDFSCluster.Builder(new HdfsConfiguration()) |
| .build(); |
| |
| cluster.waitActive(); |
| FileSystem fs = cluster.getFileSystem(); |
| |
| //open a file an write a few bytes: |
| FSDataOutputStream out = fs.create(new Path("/testBlockScheduledCounter")); |
| for (int i=0; i<1024; i++) { |
| out.write(i); |
| } |
| // flush to make sure a block is allocated. |
| out.hflush(); |
| |
| ArrayList<DatanodeDescriptor> dnList = new ArrayList<DatanodeDescriptor>(); |
| final DatanodeManager dm = cluster.getNamesystem().getBlockManager( |
| ).getDatanodeManager(); |
| dm.fetchDatanodes(dnList, dnList, false); |
| DatanodeDescriptor dn = dnList.get(0); |
| |
| assertEquals(1, dn.getBlocksScheduled()); |
| |
| // close the file and the counter should go to zero. |
| out.close(); |
| assertEquals(0, dn.getBlocksScheduled()); |
| } |
| } |