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; import java.io.DataInputStream; import java.io.EOFException; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.math.BigInteger; import java.security.MessageDigest; import java.util.Iterator; import java.util.Random; 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.fs.FSDataOutputStream; 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.server.common.Storage; import org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory; import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeDirType; import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; /** * Startup and checkpoint tests * */ public class TestStorageRestore extends TestCase { public static final String NAME_NODE_HOST = "localhost:"; public static final String NAME_NODE_HTTP_HOST = "0.0.0.0:"; private static final Log LOG = LogFactory.getLog(TestStorageRestore.class.getName()); private Configuration config; private File hdfsDir = null; static final long seed = 0xAAAAEEFL; static final int blockSize = 4096; static final int fileSize = 8192; private File path1, path2, path3; private MiniDFSCluster cluster; private void writeFile(FileSystem fileSys, Path name, int repl) throws IOException { FSDataOutputStream stm = fileSys.create(name, true, fileSys.getConf().getInt("io.file.buffer.size", 4096), (short) repl, (long) blockSize); byte[] buffer = new byte[fileSize]; Random rand = new Random(seed); rand.nextBytes(buffer); stm.write(buffer); stm.close(); } protected void setUp() throws Exception { config = new Configuration(); String baseDir = System.getProperty("test.build.data", "/tmp"); hdfsDir = new File(baseDir, "dfs"); if (hdfsDir.exists() && !FileUtil.fullyDelete(hdfsDir)) { throw new IOException("Could not delete hdfs directory '" + hdfsDir + "'"); } hdfsDir.mkdir(); path1 = new File(hdfsDir, "name1"); path2 = new File(hdfsDir, "name2"); path3 = new File(hdfsDir, "name3"); path1.mkdir(); path2.mkdir(); path3.mkdir(); if (!path2.exists() || !path3.exists() || !path1.exists()) { throw new IOException("Couldn't create dfs.name dirs"); } String dfs_name_dir = new String(path1.getPath() + "," + path2.getPath()); System.out.println("configuring hdfsdir is " + hdfsDir.getAbsolutePath() + "; dfs_name_dir = " + dfs_name_dir + ";dfs_name_edits_dir(only)=" + path3.getPath()); config.set("dfs.name.dir", dfs_name_dir); config.set("dfs.name.edits.dir", dfs_name_dir + "," + path3.getPath()); config.set("fs.checkpoint.dir", new File(hdfsDir, "secondary").getPath()); FileSystem.setDefaultUri(config, "hdfs://" + NAME_NODE_HOST + "0"); config.set("dfs.secondary.http.address", "0.0.0.0:0"); // set the restore feature on config.setBoolean(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_RESTORE_KEY, true); } /** * clean up */ public void tearDown() throws Exception { restoreAccess(); if (hdfsDir.exists() && !FileUtil.fullyDelete(hdfsDir)) { throw new IOException("Could not delete hdfs directory in tearDown '" + hdfsDir + "'"); } } /** * invalidate storage by removing sub-directory "current" in name2 and name3 */ public void invalidateStorage(FSImage fi) throws IOException { for (Iterator<StorageDirectory> it = fi.dirIterator(); it.hasNext();) { StorageDirectory sd = it.next(); if (sd.getRoot().equals(path2) || sd.getRoot().equals(path3)) { fi.getEditLog().removeEditsForStorageDir(sd); fi.updateRemovedDirs(sd); it.remove(); } } } /** * invalidate storage by removing xwr permission from name2 and name3 */ public void removeStorageAccess(FSImage fi) throws IOException { path2.setReadable(false); path2.setExecutable(false); path2.setWritable(false); path3.setReadable(false); path3.setExecutable(false); path3.setWritable(false); for (Iterator<StorageDirectory> it = fi.dirIterator(); it.hasNext();) { StorageDirectory sd = it.next(); if (sd.getRoot().equals(path2) || sd.getRoot().equals(path3)) { fi.getEditLog().removeEditsForStorageDir(sd); fi.updateRemovedDirs(sd, null); it.remove(); } } } public void restoreAccess() { if (path2.exists()) { path2.setReadable(true); path2.setExecutable(true); path2.setWritable(true); } if (path3.exists()) { path3.setReadable(true); path3.setExecutable(true); path3.setWritable(true); } } /** * get the total number of healthy storage directories */ public int numStorageDirs(FSImage fi) throws IOException { int sum = 0; for (Iterator<StorageDirectory> it = fi.dirIterator(); it.hasNext();) { sum++; } return sum; } /** * test */ public void printStorages(FSImage fs) { LOG.info("current storages and corresoponding sizes:"); for (Iterator<StorageDirectory> it = fs.dirIterator(); it.hasNext();) { StorageDirectory sd = it.next(); if (sd.getStorageDirType().isOfType(NameNodeDirType.IMAGE)) { File imf = FSImage.getImageFile(sd, NameNodeFile.IMAGE); LOG.info(" image file " + imf.getAbsolutePath() + "; len = " + imf.length()); } if (sd.getStorageDirType().isOfType(NameNodeDirType.EDITS)) { File edf = FSImage.getImageFile(sd, NameNodeFile.EDITS); LOG.info(" edits file " + edf.getAbsolutePath() + "; len = " + edf.length()); } } } /** * This function returns a md5 hash of a file. * * @param file input file * @return The md5 string */ public String getFileMD5(File file) throws Exception { String res = new String(); MessageDigest mD = MessageDigest.getInstance("MD5"); DataInputStream dis = new DataInputStream(new FileInputStream(file)); try { while (true) { mD.update(dis.readByte()); } } catch (EOFException eof) { } BigInteger bigInt = new BigInteger(1, mD.digest()); res = bigInt.toString(16); dis.close(); return res; } /** * check if files exist/not exist */ public void checkFiles(boolean valid) { // look at the valid storage File fsImg1 = new File(path1, Storage.STORAGE_DIR_CURRENT + "/" + NameNodeFile.IMAGE.getName()); File fsImg2 = new File(path2, Storage.STORAGE_DIR_CURRENT + "/" + NameNodeFile.IMAGE.getName()); File fsImg3 = new File(path3, Storage.STORAGE_DIR_CURRENT + "/" + NameNodeFile.IMAGE.getName()); File fsEdits1 = new File(path1, Storage.STORAGE_DIR_CURRENT + "/" + NameNodeFile.EDITS.getName()); File fsEdits2 = new File(path2, Storage.STORAGE_DIR_CURRENT + "/" + NameNodeFile.EDITS.getName()); File fsEdits3 = new File(path3, Storage.STORAGE_DIR_CURRENT + "/" + NameNodeFile.EDITS.getName()); this.printStorages(cluster.getNameNode().getFSImage()); String md5_1 = null, md5_2 = null, md5_3 = null; try { md5_1 = getFileMD5(fsEdits1); md5_2 = getFileMD5(fsEdits2); md5_3 = getFileMD5(fsEdits3); } catch (Exception e) { System.err.println("md 5 calculation failed:" + e.getLocalizedMessage()); } LOG.info("++++ image files = " + fsImg1.getAbsolutePath() + "," + fsImg2.getAbsolutePath() + "," + fsImg3.getAbsolutePath()); LOG.info("++++ edits files = " + fsEdits1.getAbsolutePath() + "," + fsEdits2.getAbsolutePath() + "," + fsEdits3.getAbsolutePath()); LOG.info("checkFiles compares lengths: img1=" + fsImg1.length() + ",img2=" + fsImg2.length() + ",img3=" + fsImg3.length()); LOG.info("checkFiles compares lengths: edits1=" + fsEdits1.length() + ",edits2=" + fsEdits2.length() + ",edits3=" + fsEdits3.length()); if (valid) { // should be the same assertTrue(fsImg1.length() == fsImg2.length()); assertTrue(0 == fsImg3.length()); // shouldn't be created assertTrue(fsEdits1.length() == fsEdits2.length()); assertTrue(md5_1.equals(md5_2)); assertTrue(md5_1.equals(md5_3)); } else { // should be different assertFalse(md5_1.equals(md5_2)); assertFalse(md5_1.equals(md5_2)); } } /** * test * 1. create DFS cluster with 3 storage directories * - 2 EDITS_IMAGE(name1, name2), 1 EDITS(name3) * 2. create a cluster and write a file * 3. corrupt/disable name2 and name3 by removing subdir "current" * 4. run doCheckpoint - it will fail on removed dirs (which will invalidate the storages) * 5. write another file * 6. check that edits and fsimage differ * 7. run doCheckpoint * 8. verify that all the image and edits files are the same. */ public void testStorageRestore() throws Exception { int numDatanodes = 2; cluster = new MiniDFSCluster(0, config, numDatanodes, true, false, true, null, null, null, null); cluster.waitActive(); SecondaryNameNode secondary = new SecondaryNameNode(config); System.out.println("****testStorageRestore: Cluster and SNN started"); printStorages(cluster.getNameNode().getFSImage()); FileSystem fs = cluster.getFileSystem(); Path path = new Path("/", "test"); writeFile(fs, path, 2); System.out.println("****testStorageRestore: file test written, invalidating storage..."); invalidateStorage(cluster.getNameNode().getFSImage()); printStorages(cluster.getNameNode().getFSImage()); System.out.println("****testStorageRestore: storage invalidated + doCheckpoint"); path = new Path("/", "test1"); writeFile(fs, path, 2); System.out.println("****testStorageRestore: file test1 written"); checkFiles(false); // SHOULD BE FALSE System.out.println("****testStorageRestore: checkfiles(false) run"); secondary.doCheckpoint(); // /should enable storage.. checkFiles(true); //use the recovered dir to restart nn if (!FileUtil.fullyDelete(path1)) { throw new Exception("Can't fully delete " + path1); } if (!FileUtil.fullyDelete(path3)) { throw new Exception("Can't fully delete " + path3); } cluster.restartDataNodes(); cluster.waitActive(); File tmpfile = new File("/test"); assert (tmpfile.exists()); tmpfile = new File("/test1"); assert (tmpfile.exists()); System.out.println("****testStorageRestore: second Checkpoint done and checkFiles(true) run"); secondary.shutdown(); cluster.shutdown(); } /** * 1. create DFS cluster with 3 storage directories * - 2 EDITS_IMAGE(name1, name2), 1 EDITS(name3) * 2. create a file * 3. corrupt/disable name2 and name3 by removing xwr permission * 4. run doCheckpoint - it will fail on removed dirs (which will invalidate the storages) * 5. write another file * 6. check that edits and fsimage differ * 7. run doCheckpoint - recover should fail but checkpoint should succeed * 8. restore the access permission for name2 and name 3, run checkpoint again * 9. verify that all the image and edits files are the same. */ public void testStorageRestoreFailure() throws Exception { int numDatanodes = 2; cluster = new MiniDFSCluster(0, config, numDatanodes, true, false, true, null, null, null, null); cluster.waitActive(); SecondaryNameNode secondary = new SecondaryNameNode(config); System.out.println("****testStorageRestore: Cluster and SNN started"); printStorages(cluster.getNameNode().getFSImage()); FileSystem fs = cluster.getFileSystem(); Path path = new Path("/", "test"); writeFile(fs, path, 2); System.out.println("****testStorageRestore: file test written, invalidating storage..."); removeStorageAccess(cluster.getNameNode().getFSImage()); printStorages(cluster.getNameNode().getFSImage()); System.out.println("****testStorageRestore: storage invalidated + doCheckpoint"); path = new Path("/", "test1"); writeFile(fs, path, 2); System.out.println("****testStorageRestore: file test1 written"); assert (numStorageDirs(cluster.getNameNode().getFSImage()) == 1); System.out.println("****testStorageRestore: checkfiles(false) run"); secondary.doCheckpoint(); // still can't recover removed storage dirs assert (numStorageDirs(cluster.getNameNode().getFSImage()) == 1); restoreAccess(); secondary.doCheckpoint(); // should restore removed storage dirs checkFiles(true); System.out.println("****testStorageRestore: second Checkpoint done and checkFiles(true) run"); secondary.shutdown(); cluster.shutdown(); } }