/**
* 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.tools.offlineImageViewer;
import java.io.BufferedInputStream;
import java.io.DataInputStream;
import java.io.EOFException;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.OptionBuilder;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;
import org.apache.commons.cli.PosixParser;
import org.apache.hadoop.classification.InterfaceAudience;
/**
* OfflineImageViewer to dump the contents of an Hadoop image file to XML
* or the console. Main entry point into utility, either via the
* command line or programatically.
*/
@InterfaceAudience.Private
public class OfflineImageViewer {
private final static String usage =
"Usage: bin/hdfs oiv [OPTIONS] -i INPUTFILE -o OUTPUTFILE\n" +
"Offline Image Viewer\n" +
"View a Hadoop fsimage INPUTFILE using the specified PROCESSOR,\n" +
"saving the results in OUTPUTFILE.\n" +
"\n" +
"The oiv utility will attempt to parse correctly formed image files\n" +
"and will abort fail with mal-formed image files.\n" +
"\n" +
"The tool works offline and does not require a running cluster in\n" +
"order to process an image file.\n" +
"\n" +
"The following image processors are available:\n" +
" * Ls: The default image processor generates an lsr-style listing\n" +
" of the files in the namespace, with the same fields in the same\n" +
" order. Note that in order to correctly determine file sizes,\n" +
" this formatter cannot skip blocks and will override the\n" +
" -skipBlocks option.\n" +
" * Indented: This processor enumerates over all of the elements in\n" +
" the fsimage file, using levels of indentation to delineate\n" +
" sections within the file.\n" +
" * Delimited: Generate a text file with all of the elements common\n" +
" to both inodes and inodes-under-construction, separated by a\n" +
" delimiter. The default delimiter is \u0001, though this may be\n" +
" changed via the -delimiter argument. This processor also overrides\n" +
" the -skipBlocks option for the same reason as the Ls processor\n" +
" * XML: This processor creates an XML document with all elements of\n" +
" the fsimage enumerated, suitable for further analysis by XML\n" +
" tools.\n" +
" * FileDistribution: This processor analyzes the file size\n" +
" distribution in the image.\n" +
" -maxSize specifies the range [0, maxSize] of file sizes to be\n" +
" analyzed (128GB by default).\n" +
" -step defines the granularity of the distribution. (2MB by default)\n" +
" * NameDistribution: This processor analyzes the file names\n" +
" in the image and prints total number of file names and how frequently" +
" file names are reused.\n" +
"\n" +
"Required command line arguments:\n" +
"-i,--inputFile <arg> FSImage file to process.\n" +
"-o,--outputFile <arg> Name of output file. If the specified\n" +
" file exists, it will be overwritten.\n" +
"\n" +
"Optional command line arguments:\n" +
"-p,--processor <arg> Select which type of processor to apply\n" +
" against image file." +
" (Ls|XML|Delimited|Indented|FileDistribution).\n" +
"-h,--help Display usage information and exit\n" +
"-printToScreen For processors that write to a file, also\n" +
" output to screen. On large image files this\n" +
" will dramatically increase processing time.\n" +
"-skipBlocks Skip inodes' blocks information. May\n" +
" significantly decrease output.\n" +
" (default = false).\n" +
"-delimiter <arg> Delimiting string to use with Delimited processor\n";
private final boolean skipBlocks;
private final String inputFile;
private final ImageVisitor processor;
public OfflineImageViewer(String inputFile, ImageVisitor processor,
boolean skipBlocks) {
this.inputFile = inputFile;
this.processor = processor;
this.skipBlocks = skipBlocks;
}
/**
* Process image file.
*/
public void go() throws IOException {
DataInputStream in = null;
try {
in = new DataInputStream(new BufferedInputStream(
new FileInputStream(new File(inputFile))));
int imageVersionFile = findImageVersion(in);
ImageLoader fsip =
ImageLoader.LoaderFactory.getLoader(imageVersionFile);
if(fsip == null)
throw new IOException("No image processor to read version " +
imageVersionFile + " is available.");
fsip.loadImage(in, processor, skipBlocks);
} finally {
if(in != null) in.close();
}
}
/**
* Check an fsimage datainputstream's version number.
*
* The datainput stream is returned at the same point as it was passed in;
* this method has no effect on the datainputstream's read pointer.
*
* @param in Datainputstream of fsimage
* @return Filesystem layout version of fsimage represented by stream
* @throws IOException If problem reading from in
*/
private int findImageVersion(DataInputStream in) throws IOException {
in.mark(42); // arbitrary amount, resetting immediately
int version = in.readInt();
in.reset();
return version;
}
/**
* Build command-line options and descriptions
*/
public static Options buildOptions() {
Options options = new Options();
// Build in/output file arguments, which are required, but there is no
// addOption method that can specify this
OptionBuilder.isRequired();
OptionBuilder.hasArgs();
OptionBuilder.withLongOpt("outputFile");
options.addOption(OptionBuilder.create("o"));
OptionBuilder.isRequired();
OptionBuilder.hasArgs();
OptionBuilder.withLongOpt("inputFile");
options.addOption(OptionBuilder.create("i"));
options.addOption("p", "processor", true, "");
options.addOption("h", "help", false, "");
options.addOption("skipBlocks", false, "");
options.addOption("printToScreen", false, "");
options.addOption("delimiter", true, "");
return options;
}
/**
* Entry point to command-line-driven operation. User may specify
* options and start fsimage viewer from the command line. Program
* will process image file and exit cleanly or, if an error is
* encountered, inform user and exit.
*
* @param args Command line options
* @throws IOException
*/
public static void main(String[] args) throws IOException {
Options options = buildOptions();
if(args.length == 0) {
printUsage();
return;
}
CommandLineParser parser = new PosixParser();
CommandLine cmd;
try {
cmd = parser.parse(options, args);
} catch (ParseException e) {
System.out.println("Error parsing command-line options: ");
printUsage();
return;
}
if(cmd.hasOption("h")) { // print help and exit
printUsage();
return;
}
boolean skipBlocks = cmd.hasOption("skipBlocks");
boolean printToScreen = cmd.hasOption("printToScreen");
String inputFile = cmd.getOptionValue("i");
String processor = cmd.getOptionValue("p", "Ls");
String outputFile = cmd.getOptionValue("o");
String delimiter = cmd.getOptionValue("delimiter");
if( !(delimiter == null || processor.equals("Delimited")) ) {
System.out.println("Can only specify -delimiter with Delimited processor");
printUsage();
return;
}
ImageVisitor v;
if(processor.equals("Indented")) {
v = new IndentedImageVisitor(outputFile, printToScreen);
} else if (processor.equals("XML")) {
v = new XmlImageVisitor(outputFile, printToScreen);
} else if (processor.equals("Delimited")) {
v = delimiter == null ?
new DelimitedImageVisitor(outputFile, printToScreen) :
new DelimitedImageVisitor(outputFile, printToScreen, delimiter);
skipBlocks = false;
} else if (processor.equals("FileDistribution")) {
long maxSize = Long.parseLong(cmd.getOptionValue("maxSize", "0"));
int step = Integer.parseInt(cmd.getOptionValue("step", "0"));
v = new FileDistributionVisitor(outputFile, maxSize, step);
} else if (processor.equals("NameDistribution")) {
v = new NameDistributionVisitor(outputFile, printToScreen);
} else {
v = new LsImageVisitor(outputFile, printToScreen);
skipBlocks = false;
}
try {
OfflineImageViewer d = new OfflineImageViewer(inputFile, v, skipBlocks);
d.go();
} catch (EOFException e) {
System.err.println("Input file ended unexpectedly. Exiting");
} catch(IOException e) {
System.err.println("Encountered exception. Exiting: " + e.getMessage());
}
}
/**
* Print application usage instructions.
*/
private static void printUsage() {
System.out.println(usage);
}
}