| /** |
| * 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 org.apache.hadoop.util.DiskChecker.DiskErrorException; |
| |
| import java.io.File; |
| import java.io.IOException; |
| import java.nio.file.Files; |
| import java.nio.file.Path; |
| import java.util.Arrays; |
| import java.util.Random; |
| import java.util.concurrent.TimeUnit; |
| |
| /** |
| * ReadWriteDiskValidator is the class to check a directory by to create a file, |
| * write some bytes into it, read back, and verify if they are identical. |
| * Read time and write time are recorded and put into an |
| * {@link ReadWriteDiskValidatorMetrics}. |
| */ |
| public class ReadWriteDiskValidator implements DiskValidator { |
| |
| public static final String NAME = "read-write"; |
| private static final Random RANDOM = new Random(); |
| |
| @Override |
| public void checkStatus(File dir) throws DiskErrorException { |
| ReadWriteDiskValidatorMetrics metric = |
| ReadWriteDiskValidatorMetrics.getMetric(dir.toString()); |
| Path tmpFile = null; |
| try { |
| if (!dir.isDirectory()) { |
| metric.diskCheckFailed(); |
| throw new DiskErrorException(dir + " is not a directory!"); |
| } |
| |
| // check the directory presence and permission. |
| DiskChecker.checkDir(dir); |
| |
| // create a tmp file under the dir |
| tmpFile = Files.createTempFile(dir.toPath(), "test", "tmp"); |
| |
| // write 16 bytes into the tmp file |
| byte[] inputBytes = new byte[16]; |
| RANDOM.nextBytes(inputBytes); |
| long startTime = System.nanoTime(); |
| Files.write(tmpFile, inputBytes); |
| long writeLatency = TimeUnit.MICROSECONDS.convert( |
| System.nanoTime() - startTime, TimeUnit.NANOSECONDS); |
| metric.addWriteFileLatency(writeLatency); |
| |
| // read back |
| startTime = System.nanoTime(); |
| byte[] outputBytes = Files.readAllBytes(tmpFile); |
| long readLatency = TimeUnit.MICROSECONDS.convert( |
| System.nanoTime() - startTime, TimeUnit.NANOSECONDS); |
| metric.addReadFileLatency(readLatency); |
| |
| // validation |
| if (!Arrays.equals(inputBytes, outputBytes)) { |
| metric.diskCheckFailed(); |
| throw new DiskErrorException("Data in file has been corrupted."); |
| } |
| } catch (IOException e) { |
| metric.diskCheckFailed(); |
| throw new DiskErrorException("Disk Check failed!", e); |
| } finally { |
| // delete the file |
| if (tmpFile != null) { |
| try { |
| Files.delete(tmpFile); |
| } catch (IOException e) { |
| metric.diskCheckFailed(); |
| throw new DiskErrorException("File deletion failed!", e); |
| } |
| } |
| } |
| } |
| } |