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.dfs; import java.io.File; import junit.framework.TestCase; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.dfs.FSConstants.NodeType; import static org.apache.hadoop.dfs.FSConstants.NodeType.NAME_NODE; import static org.apache.hadoop.dfs.FSConstants.NodeType.DATA_NODE; import org.apache.hadoop.dfs.FSConstants.StartupOption; import org.apache.hadoop.fs.Path; /** * This test ensures the appropriate response (successful or failure) from * a Datanode when the system is started with differing version combinations. */ public class TestDFSStartupVersions extends TestCase { private static final Log LOG = LogFactory.getLog("org.apache.hadoop.dfs.TestDFSStartupVersions"); private static Path TEST_ROOT_DIR = new Path( System.getProperty("test.build.data", "/tmp").toString().replace(' ', '+')); private MiniDFSCluster cluster = null; /** * Writes an INFO log message containing the parameters. */ void log(String label, NodeType nodeType, Integer testCase, StorageInfo version) { String testCaseLine = ""; if (testCase != null) { testCaseLine = " testCase=" + testCase; } LOG.info("============================================================"); LOG.info("***TEST*** " + label + ":" + testCaseLine + " nodeType=" + nodeType + " layoutVersion=" + version.getLayoutVersion() + " namespaceID=" + version.getNamespaceID() + " fsscTime=" + version.getCTime()); } /** * Initialize the versions array. This array stores all combinations * of cross product: * {oldLayoutVersion,currentLayoutVersion,futureLayoutVersion} X * {currentNamespaceId,incorrectNamespaceId} X * {pastFsscTime,currentFsscTime,futureFsscTime} */ private StorageInfo[] initializeVersions() throws Exception { int layoutVersionOld = Storage.LAST_UPGRADABLE_LAYOUT_VERSION; int layoutVersionCur = UpgradeUtilities.getCurrentLayoutVersion(); int layoutVersionNew = Integer.MIN_VALUE; int namespaceIdCur = UpgradeUtilities.getCurrentNamespaceID(null); int namespaceIdOld = Integer.MIN_VALUE; long fsscTimeOld = Long.MIN_VALUE; long fsscTimeCur = UpgradeUtilities.getCurrentFsscTime(null); long fsscTimeNew = Long.MAX_VALUE; return new StorageInfo[] { new StorageInfo(layoutVersionOld, namespaceIdCur, fsscTimeOld), // 0 new StorageInfo(layoutVersionOld, namespaceIdCur, fsscTimeCur), // 1 new StorageInfo(layoutVersionOld, namespaceIdCur, fsscTimeNew), // 2 new StorageInfo(layoutVersionOld, namespaceIdOld, fsscTimeOld), // 3 new StorageInfo(layoutVersionOld, namespaceIdOld, fsscTimeCur), // 4 new StorageInfo(layoutVersionOld, namespaceIdOld, fsscTimeNew), // 5 new StorageInfo(layoutVersionCur, namespaceIdCur, fsscTimeOld), // 6 new StorageInfo(layoutVersionCur, namespaceIdCur, fsscTimeCur), // 7 new StorageInfo(layoutVersionCur, namespaceIdCur, fsscTimeNew), // 8 new StorageInfo(layoutVersionCur, namespaceIdOld, fsscTimeOld), // 9 new StorageInfo(layoutVersionCur, namespaceIdOld, fsscTimeCur), // 10 new StorageInfo(layoutVersionCur, namespaceIdOld, fsscTimeNew), // 11 new StorageInfo(layoutVersionNew, namespaceIdCur, fsscTimeOld), // 12 new StorageInfo(layoutVersionNew, namespaceIdCur, fsscTimeCur), // 13 new StorageInfo(layoutVersionNew, namespaceIdCur, fsscTimeNew), // 14 new StorageInfo(layoutVersionNew, namespaceIdOld, fsscTimeOld), // 15 new StorageInfo(layoutVersionNew, namespaceIdOld, fsscTimeCur), // 16 new StorageInfo(layoutVersionNew, namespaceIdOld, fsscTimeNew), // 17 }; } /** * Determines if the given Namenode version and Datanode version * are compatible with each other. Compatibility in this case mean * that the Namenode and Datanode will successfully start up and * will work together. The rules for compatibility, * taken from the DFS Upgrade Design, are as follows: * <pre> * 1. The data-node does regular startup (no matter which options * it is started with) if * softwareLV == storedLV AND * DataNode.FSSCTime == NameNode.FSSCTime * 2. The data-node performs an upgrade if it is started without any * options and * |softwareLV| > |storedLV| OR * (softwareLV == storedLV AND * DataNode.FSSCTime < NameNode.FSSCTime) * 3. NOT TESTED: The data-node rolls back if it is started with * the -rollback option and * |softwareLV| >= |previous.storedLV| AND * DataNode.previous.FSSCTime <= NameNode.FSSCTime * 4. In all other cases the startup fails. * </pre> */ boolean isVersionCompatible(StorageInfo namenodeVer, StorageInfo datanodeVer) { // check #0 if (namenodeVer.getNamespaceID() != datanodeVer.getNamespaceID()) { LOG.info("namespaceIDs are not equal: isVersionCompatible=false"); return false; } // check #1 int softwareLV = FSConstants.LAYOUT_VERSION; // will also be Namenode's LV int storedLV = datanodeVer.getLayoutVersion(); if (softwareLV == storedLV && datanodeVer.getCTime() == namenodeVer.getCTime()) { LOG.info("layoutVersions and cTimes are equal: isVersionCompatible=true"); return true; } // check #2 long absSoftwareLV = Math.abs((long) softwareLV); long absStoredLV = Math.abs((long) storedLV); if (absSoftwareLV > absStoredLV || (softwareLV == storedLV && datanodeVer.getCTime() < namenodeVer.getCTime())) { LOG.info("softwareLayoutVersion is newer OR namenode cTime is newer: isVersionCompatible=true"); return true; } // check #4 LOG.info("default case: isVersionCompatible=false"); return false; } /** * This test ensures the appropriate response (successful or failure) from * a Datanode when the system is started with differing version combinations. * <pre> * For each 3-tuple in the cross product * ({oldLayoutVersion,currentLayoutVersion,futureLayoutVersion}, * {currentNamespaceId,incorrectNamespaceId}, * {pastFsscTime,currentFsscTime,futureFsscTime}) * 1. Startup Namenode with version file containing * (currentLayoutVersion,currentNamespaceId,currentFsscTime) * 2. Attempt to startup Datanode with version file containing * this iterations version 3-tuple * </pre> */ public void testVersions() throws Exception { UpgradeUtilities.initialize(); Configuration conf = UpgradeUtilities.initializeStorageStateConf(1, new Configuration()); StorageInfo[] versions = initializeVersions(); UpgradeUtilities.createStorageDirs(NAME_NODE, conf.getStrings("dfs.name.dir"), "current"); cluster = new MiniDFSCluster(conf, 0, StartupOption.REGULAR); StorageInfo nameNodeVersion = new StorageInfo(UpgradeUtilities.getCurrentLayoutVersion(), UpgradeUtilities.getCurrentNamespaceID(cluster), UpgradeUtilities.getCurrentFsscTime(cluster)); log("NameNode version info", NAME_NODE, null, nameNodeVersion); for (int i = 0; i < versions.length; i++) { File[] storage = UpgradeUtilities.createStorageDirs(DATA_NODE, conf.getStrings("dfs.data.dir"), "current"); log("DataNode version info", DATA_NODE, i, versions[i]); UpgradeUtilities.createVersionFile(DATA_NODE, storage, versions[i]); try { cluster.startDataNodes(conf, 1, false, StartupOption.REGULAR, null); } catch (Exception ignore) { // Ignore. The asserts below will check for problems. // ignore.printStackTrace(); } assertTrue(cluster.getNameNode() != null); assertEquals(isVersionCompatible(nameNodeVersion, versions[i]), cluster.isDataNodeUp()); cluster.shutdownDataNodes(); } } protected void tearDown() throws Exception { LOG.info("Shutting down MiniDFSCluster"); if (cluster != null) cluster.shutdown(); } public static void main(String[] args) throws Exception { new TestDFSStartupVersions().testVersions(); } }