Java tutorial
/** * 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.ha; import static org.junit.Assert.*; import java.io.File; import java.io.IOException; import java.net.URI; import java.net.URISyntaxException; import java.util.Collection; import java.util.List; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.FileUtil; import org.apache.hadoop.fs.Path; import org.apache.hadoop.hdfs.DFSConfigKeys; import org.apache.hadoop.hdfs.MiniDFSCluster; import org.apache.hadoop.hdfs.MiniDFSNNTopology; import org.apache.hadoop.hdfs.server.namenode.FSNamesystem; import org.apache.hadoop.hdfs.server.namenode.NNStorage; import org.apache.hadoop.hdfs.server.namenode.NameNode; import org.apache.hadoop.test.GenericTestUtils; import org.junit.Test; import org.mockito.Mockito; import com.google.common.base.Joiner; public class TestFailureOfSharedDir { private static final Log LOG = LogFactory.getLog(TestFailureOfSharedDir.class); /** * Test that the shared edits dir is automatically added to the list of edits * dirs that are marked required. */ @Test public void testSharedDirIsAutomaticallyMarkedRequired() throws URISyntaxException { URI foo = new URI("file:/foo"); URI bar = new URI("file:/bar"); Configuration conf = new Configuration(); conf.set(DFSConfigKeys.DFS_NAMENODE_EDITS_DIR_KEY, Joiner.on(",").join(foo, bar)); conf.set(DFSConfigKeys.DFS_NAMENODE_EDITS_DIR_REQUIRED_KEY, foo.toString()); assertFalse(FSNamesystem.getRequiredNamespaceEditsDirs(conf).contains(bar)); conf.set(DFSConfigKeys.DFS_NAMENODE_SHARED_EDITS_DIR_KEY, bar.toString()); Collection<URI> requiredEditsDirs = FSNamesystem.getRequiredNamespaceEditsDirs(conf); assertTrue(Joiner.on(",").join(requiredEditsDirs) + " does not contain " + bar, requiredEditsDirs.contains(bar)); } /** * Multiple shared edits directories is an invalid configuration. */ @Test public void testMultipleSharedDirsFails() throws Exception { Configuration conf = new Configuration(); URI sharedA = new URI("file:///shared-A"); URI sharedB = new URI("file:///shared-B"); URI localA = new URI("file:///local-A"); conf.set(DFSConfigKeys.DFS_NAMENODE_SHARED_EDITS_DIR_KEY, Joiner.on(",").join(sharedA, sharedB)); conf.set(DFSConfigKeys.DFS_NAMENODE_EDITS_DIR_KEY, localA.toString()); try { FSNamesystem.getNamespaceEditsDirs(conf); fail("Allowed multiple shared edits directories"); } catch (IOException ioe) { assertEquals("Multiple shared edits directories are not yet supported", ioe.getMessage()); } } /** * Make sure that the shared edits dirs are listed before non-shared dirs * when the configuration is parsed. This ensures that the shared journals * are synced before the local ones. */ @Test public void testSharedDirsComeFirstInEditsList() throws Exception { Configuration conf = new Configuration(); URI sharedA = new URI("file:///shared-A"); URI localA = new URI("file:///local-A"); URI localB = new URI("file:///local-B"); URI localC = new URI("file:///local-C"); conf.set(DFSConfigKeys.DFS_NAMENODE_SHARED_EDITS_DIR_KEY, sharedA.toString()); // List them in reverse order, to make sure they show up in // the order listed, regardless of lexical sort order. conf.set(DFSConfigKeys.DFS_NAMENODE_EDITS_DIR_KEY, Joiner.on(",").join(localC, localB, localA)); List<URI> dirs = FSNamesystem.getNamespaceEditsDirs(conf); assertEquals( "Shared dirs should come first, then local dirs, in the order " + "they were listed in the configuration.", Joiner.on(",").join(sharedA, localC, localB, localA), Joiner.on(",").join(dirs)); } /** * Test that marking the shared edits dir as being "required" causes the NN to * fail if that dir can't be accessed. */ @Test public void testFailureOfSharedDir() throws Exception { Configuration conf = new Configuration(); // The shared edits dir will automatically be marked required. MiniDFSCluster cluster = null; File sharedEditsDir = null; try { cluster = new MiniDFSCluster.Builder(conf).nnTopology(MiniDFSNNTopology.simpleHATopology()) .numDataNodes(0).build(); cluster.waitActive(); cluster.transitionToActive(0); FileSystem fs = HATestUtil.configureFailoverFs(cluster, conf); assertTrue(fs.mkdirs(new Path("/test1"))); // Blow away the shared edits dir. Runtime mockRuntime = Mockito.mock(Runtime.class); URI sharedEditsUri = cluster.getSharedEditsDir(0, 1); sharedEditsDir = new File(sharedEditsUri); assertEquals(0, FileUtil.chmod(sharedEditsDir.getAbsolutePath(), "-w", true)); NameNode nn0 = cluster.getNameNode(0); nn0.getNamesystem().getFSImage().getEditLog().getJournalSet().setRuntimeForTesting(mockRuntime); try { // Make sure that subsequent operations on the NN fail. nn0.getRpcServer().rollEditLog(); fail("Succeeded in rolling edit log despite shared dir being deleted"); } catch (IOException ioe) { GenericTestUtils.assertExceptionContains( "Unable to start log segment 4: too few journals successfully started", ioe); // By current policy the NN should exit upon this error. // exit() should be called once, but since it is mocked, exit gets // called once during FSEditsLog.endCurrentLogSegment() and then after // that during FSEditsLog.startLogSegment(). So the check is atLeast(1) Mockito.verify(mockRuntime, Mockito.atLeastOnce()).exit(Mockito.anyInt()); LOG.info("Got expected exception", ioe); } // Check that none of the edits dirs rolled, since the shared edits // dir didn't roll. Regression test for HDFS-2874. for (URI editsUri : cluster.getNameEditsDirs(0)) { if (editsUri.equals(sharedEditsUri)) { continue; } File editsDir = new File(editsUri.getPath()); File curDir = new File(editsDir, "current"); GenericTestUtils.assertGlobEquals(curDir, "edits_.*", NNStorage.getInProgressEditsFileName(1)); } } finally { if (sharedEditsDir != null) { // without this test cleanup will fail FileUtil.chmod(sharedEditsDir.getAbsolutePath(), "+w", true); } if (cluster != null) { cluster.shutdown(); } } } }