| /** |
| * 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.util; |
| |
| import java.io.File; |
| import java.io.FileNotFoundException; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.util.UUID; |
| import java.util.concurrent.atomic.AtomicReference; |
| |
| import com.google.common.annotations.VisibleForTesting; |
| import org.apache.commons.io.FileUtils; |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.fs.FileUtil; |
| import org.apache.hadoop.fs.LocalFileSystem; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.fs.permission.FsPermission; |
| import org.apache.hadoop.io.IOUtils; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Class that provides utility functions for checking disk problem |
| */ |
| @InterfaceAudience.Private |
| @InterfaceStability.Unstable |
| public class DiskChecker { |
| public static final Logger LOG = LoggerFactory.getLogger(DiskChecker.class); |
| |
| public static class DiskErrorException extends IOException { |
| public DiskErrorException(String msg) { |
| super(msg); |
| } |
| |
| public DiskErrorException(String msg, Throwable cause) { |
| super(msg, cause); |
| } |
| } |
| |
| public static class DiskOutOfSpaceException extends IOException { |
| public DiskOutOfSpaceException(String msg) { |
| super(msg); |
| } |
| } |
| |
| // Provider that abstracts some FileOutputStream operations for |
| // testability. |
| private static AtomicReference<FileIoProvider> fileIoProvider = |
| new AtomicReference<FileIoProvider>(new DefaultFileIoProvider()); |
| |
| /** |
| * Create the directory if it doesn't exist and check that dir is readable, |
| * writable and executable |
| * |
| * @param dir |
| * @throws DiskErrorException |
| */ |
| public static void checkDir(File dir) throws DiskErrorException { |
| if (!mkdirsWithExistsCheck(dir)) { |
| throw new DiskErrorException("Cannot create directory: " |
| + dir.toString()); |
| } |
| checkAccessByFileMethods(dir); |
| doDiskIo(dir); |
| } |
| |
| /** |
| * Create the local directory if necessary, check permissions and also ensure |
| * it can be read from and written into. |
| * |
| * @param localFS local filesystem |
| * @param dir directory |
| * @param expected permission |
| * @throws DiskErrorException |
| * @throws IOException |
| */ |
| public static void checkDir(LocalFileSystem localFS, Path dir, |
| FsPermission expected) |
| throws DiskErrorException, IOException { |
| mkdirsWithExistsAndPermissionCheck(localFS, dir, expected); |
| checkAccessByFileMethods(localFS.pathToFile(dir)); |
| doDiskIo(localFS.pathToFile(dir)); |
| } |
| |
| /** |
| * Checks that the current running process can read, write, and execute the |
| * given directory by using methods of the File object. |
| * |
| * @param dir File to check |
| * @throws DiskErrorException if dir is not readable, not writable, or not |
| * executable |
| */ |
| private static void checkAccessByFileMethods(File dir) |
| throws DiskErrorException { |
| if (!dir.isDirectory()) { |
| throw new DiskErrorException("Not a directory: " |
| + dir.toString()); |
| } |
| |
| if (!FileUtil.canRead(dir)) { |
| throw new DiskErrorException("Directory is not readable: " |
| + dir.toString()); |
| } |
| |
| if (!FileUtil.canWrite(dir)) { |
| throw new DiskErrorException("Directory is not writable: " |
| + dir.toString()); |
| } |
| |
| if (!FileUtil.canExecute(dir)) { |
| throw new DiskErrorException("Directory is not executable: " |
| + dir.toString()); |
| } |
| } |
| |
| /** |
| * The semantics of mkdirsWithExistsCheck method is different from the mkdirs |
| * method provided in the Sun's java.io.File class in the following way: |
| * While creating the non-existent parent directories, this method checks for |
| * the existence of those directories if the mkdir fails at any point (since |
| * that directory might have just been created by some other process). |
| * If both mkdir() and the exists() check fails for any seemingly |
| * non-existent directory, then we signal an error; Sun's mkdir would signal |
| * an error (return false) if a directory it is attempting to create already |
| * exists or the mkdir fails. |
| * @param dir |
| * @return true on success, false on failure |
| */ |
| private static boolean mkdirsWithExistsCheck(File dir) { |
| if (dir.mkdir() || dir.exists()) { |
| return true; |
| } |
| File canonDir; |
| try { |
| canonDir = dir.getCanonicalFile(); |
| } catch (IOException e) { |
| return false; |
| } |
| String parent = canonDir.getParent(); |
| return (parent != null) && |
| (mkdirsWithExistsCheck(new File(parent)) && |
| (canonDir.mkdir() || canonDir.exists())); |
| } |
| |
| /** |
| * Create the directory or check permissions if it already exists. |
| * |
| * The semantics of mkdirsWithExistsAndPermissionCheck method is different |
| * from the mkdirs method provided in the Sun's java.io.File class in the |
| * following way: |
| * While creating the non-existent parent directories, this method checks for |
| * the existence of those directories if the mkdir fails at any point (since |
| * that directory might have just been created by some other process). |
| * If both mkdir() and the exists() check fails for any seemingly |
| * non-existent directory, then we signal an error; Sun's mkdir would signal |
| * an error (return false) if a directory it is attempting to create already |
| * exists or the mkdir fails. |
| * |
| * @param localFS local filesystem |
| * @param dir directory to be created or checked |
| * @param expected expected permission |
| * @throws IOException |
| */ |
| static void mkdirsWithExistsAndPermissionCheck( |
| LocalFileSystem localFS, Path dir, FsPermission expected) |
| throws IOException { |
| File directory = localFS.pathToFile(dir); |
| boolean created = false; |
| |
| if (!directory.exists()) |
| created = mkdirsWithExistsCheck(directory); |
| |
| if (created || !localFS.getFileStatus(dir).getPermission().equals(expected)) |
| localFS.setPermission(dir, expected); |
| } |
| |
| // State related to running disk IO checks. |
| private static final String DISK_IO_FILE_PREFIX = |
| "DiskChecker.OK_TO_DELETE_."; |
| |
| @VisibleForTesting |
| static final int DISK_IO_MAX_ITERATIONS = 3; |
| |
| /** |
| * Performs some disk IO by writing to a new file in the given directory |
| * and sync'ing file contents to disk. |
| * |
| * This increases the likelihood of catching catastrophic disk/controller |
| * failures sooner. |
| * |
| * @param dir directory to be checked. |
| * @throws DiskErrorException if we hit an error while trying to perform |
| * disk IO against the file. |
| */ |
| private static void doDiskIo(File dir) throws DiskErrorException { |
| try { |
| IOException ioe = null; |
| |
| for (int i = 0; i < DISK_IO_MAX_ITERATIONS; ++i) { |
| final File file = getFileNameForDiskIoCheck(dir, i+1); |
| try { |
| diskIoCheckWithoutNativeIo(file); |
| return; |
| } catch (IOException e) { |
| // Let's retry a few times before we really give up and |
| // declare the disk as bad. |
| ioe = e; |
| } |
| } |
| throw ioe; // Just rethrow the last exception to signal failure. |
| } catch(IOException e) { |
| throw new DiskErrorException("Error checking directory " + dir, e); |
| } |
| } |
| |
| /** |
| * Try to perform some disk IO by writing to the given file |
| * without using Native IO. |
| * |
| * @param file |
| * @throws IOException if there was a non-retriable error. |
| */ |
| private static void diskIoCheckWithoutNativeIo(File file) |
| throws IOException { |
| FileOutputStream fos = null; |
| |
| try { |
| final FileIoProvider provider = fileIoProvider.get(); |
| fos = provider.get(file); |
| provider.write(fos, new byte[1]); |
| fos.getFD().sync(); |
| fos.close(); |
| fos = null; |
| if (!file.delete() && file.exists()) { |
| throw new IOException("Failed to delete " + file); |
| } |
| file = null; |
| } finally { |
| IOUtils.cleanup(null, fos); |
| FileUtils.deleteQuietly(file); |
| } |
| } |
| |
| /** |
| * Generate a path name for a test file under the given directory. |
| * |
| * @return file object. |
| */ |
| @VisibleForTesting |
| static File getFileNameForDiskIoCheck(File dir, int iterationCount) { |
| if (iterationCount < DISK_IO_MAX_ITERATIONS) { |
| // Use file names of the format prefix.001 by default. |
| return new File(dir, |
| DISK_IO_FILE_PREFIX + String.format("%03d", iterationCount)); |
| } else { |
| // If the first few checks then fail, try using a randomly generated |
| // file name. |
| return new File(dir, DISK_IO_FILE_PREFIX + UUID.randomUUID()); |
| } |
| } |
| |
| /** |
| * An interface that abstracts operations on {@link FileOutputStream} |
| * objects for testability. |
| */ |
| interface FileIoProvider { |
| FileOutputStream get(File f) throws FileNotFoundException; |
| void write(FileOutputStream fos, byte[] data) throws IOException; |
| } |
| |
| /** |
| * The default implementation of {@link FileIoProvider}. |
| */ |
| private static class DefaultFileIoProvider implements FileIoProvider { |
| /** |
| * See {@link FileOutputStream#FileOutputStream(File)}. |
| */ |
| @Override |
| public FileOutputStream get(File f) throws FileNotFoundException { |
| return new FileOutputStream(f); |
| } |
| |
| /** |
| * See {@link FileOutputStream#write(byte[])}. |
| */ |
| @Override |
| public void write(FileOutputStream fos, byte[] data) throws IOException { |
| fos.write(data); |
| } |
| } |
| |
| /** |
| * Replace the {@link FileIoProvider} for tests. |
| * This method MUST NOT be used outside of unit tests. |
| * |
| * @param newFosProvider |
| * @return the old FileIoProvider. |
| */ |
| @VisibleForTesting |
| static FileIoProvider replaceFileOutputStreamProvider( |
| FileIoProvider newFosProvider) { |
| return fileIoProvider.getAndSet(newFosProvider); |
| } |
| |
| /** |
| * Retrieve the current {@link FileIoProvider}. |
| * This method MUST NOT be used outside of unit tests. |
| * |
| * @return the current FileIoProvider. |
| */ |
| @VisibleForTesting |
| static FileIoProvider getFileOutputStreamProvider() { |
| return fileIoProvider.get(); |
| } |
| } |