/**
* 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.offlineEditsViewer;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.hdfs.tools.offlineEditsViewer.OfflineEditsLoader.OfflineEditsLoaderFactory;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
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;
/**
* This class implements an offline edits viewer, tool that
* can be used to view edit logs.
*/
@InterfaceAudience.Private
@InterfaceStability.Unstable
public class OfflineEditsViewer extends Configured implements Tool {
private final static String defaultProcessor = "xml";
/**
* Print help.
*/
private void printHelp() {
String summary =
"Usage: bin/hdfs oev [OPTIONS] -i INPUT_FILE -o OUTPUT_FILE\n" +
"Offline edits viewer\n" +
"Parse a Hadoop edits log file INPUT_FILE and save results\n" +
"in OUTPUT_FILE.\n" +
"Required command line arguments:\n" +
"-i,--inputFile <arg> edits file to process, xml (case\n" +
" insensitive) extension means XML format,\n" +
" any other filename means binary format\n" +
"-o,--outputFile <arg> Name of output file. If the specified\n" +
" file exists, it will be overwritten,\n" +
" format of the file is determined\n" +
" by -p option\n" +
"\n" +
"Optional command line arguments:\n" +
"-p,--processor <arg> Select which type of processor to apply\n" +
" against image file, currently supported\n" +
" processors are: binary (native binary format\n" +
" that Hadoop uses), xml (default, XML\n" +
" format), stats (prints statistics about\n" +
" edits file)\n" +
"-h,--help Display usage information and exit\n" +
"-f,--fix-txids Renumber the transaction IDs in the input,\n" +
" so that there are no gaps or invalid " +
" transaction IDs.\n" +
"-r,--recover When reading binary edit logs, use recovery \n" +
" mode. This will give you the chance to skip \n" +
" corrupt parts of the edit log.\n" +
"-v,--verbose More verbose output, prints the input and\n" +
" output filenames, for processors that write\n" +
" to a file, also output to screen. On large\n" +
" image files this will dramatically increase\n" +
" processing time (default is false).\n";
System.out.println(summary);
System.out.println();
ToolRunner.printGenericCommandUsage(System.out);
}
/**
* Build command-line options and descriptions
*
* @return command line options
*/
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("outputFilename");
options.addOption(OptionBuilder.create("o"));
OptionBuilder.isRequired();
OptionBuilder.hasArgs();
OptionBuilder.withLongOpt("inputFilename");
options.addOption(OptionBuilder.create("i"));
options.addOption("p", "processor", true, "");
options.addOption("v", "verbose", false, "");
options.addOption("f", "fix-txids", false, "");
options.addOption("r", "recover", false, "");
options.addOption("h", "help", false, "");
return options;
}
/** Process an edit log using the chosen processor or visitor.
*
* @param inputFilename The file to process
* @param outputFilename The output file name
* @param processor If visitor is null, the processor to use
* @param visitor If non-null, the visitor to use.
*
* @return 0 on success; error code otherwise
*/
public int go(String inputFileName, String outputFileName, String processor,
Flags flags, OfflineEditsVisitor visitor)
{
if (flags.getPrintToScreen()) {
System.out.println("input [" + inputFileName + "]");
System.out.println("output [" + outputFileName + "]");
}
try {
if (visitor == null) {
visitor = OfflineEditsVisitorFactory.getEditsVisitor(
outputFileName, processor, flags.getPrintToScreen());
}
boolean xmlInput = inputFileName.endsWith(".xml");
OfflineEditsLoader loader = OfflineEditsLoaderFactory.
createLoader(visitor, inputFileName, xmlInput, flags);
loader.loadEdits();
} catch(Exception e) {
System.err.println("Encountered exception. Exiting: " + e.getMessage());
e.printStackTrace(System.err);
return -1;
}
return 0;
}
public static class Flags {
private boolean printToScreen = false;
private boolean fixTxIds = false;
private boolean recoveryMode = false;
public Flags() {
}
public boolean getPrintToScreen() {
return printToScreen;
}
public void setPrintToScreen() {
printToScreen = true;
}
public boolean getFixTxIds() {
return fixTxIds;
}
public void setFixTxIds() {
fixTxIds = true;
}
public boolean getRecoveryMode() {
return recoveryMode;
}
public void setRecoveryMode() {
recoveryMode = true;
}
}
/**
* Main entry point for ToolRunner (see ToolRunner docs)
*
* @param argv The parameters passed to this program.
* @return 0 on success, non zero on error.
*/
@Override
public int run(String[] argv) throws Exception {
Options options = buildOptions();
if(argv.length == 0) {
printHelp();
return -1;
}
CommandLineParser parser = new PosixParser();
CommandLine cmd;
try {
cmd = parser.parse(options, argv);
} catch (ParseException e) {
System.out.println(
"Error parsing command-line options: " + e.getMessage());
printHelp();
return -1;
}
if(cmd.hasOption("h")) { // print help and exit
printHelp();
return -1;
}
String inputFileName = cmd.getOptionValue("i");
String outputFileName = cmd.getOptionValue("o");
String processor = cmd.getOptionValue("p");
if(processor == null) {
processor = defaultProcessor;
}
Flags flags = new Flags();
if (cmd.hasOption("r")) {
flags.setRecoveryMode();
}
if (cmd.hasOption("f")) {
flags.setFixTxIds();
}
if (cmd.hasOption("v")) {
flags.setPrintToScreen();
}
return go(inputFileName, outputFileName, processor, flags, null);
}
/**
* main() runs the offline edits viewer using ToolRunner
*
* @param argv Command line parameters.
*/
public static void main(String[] argv) throws Exception {
int res = ToolRunner.run(new OfflineEditsViewer(), argv);
System.exit(res);
}
}