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.nutch.scoring.webgraph; import java.io.IOException; import java.text.SimpleDateFormat; import java.util.Iterator; import org.apache.commons.cli.CommandLine; import org.apache.commons.cli.CommandLineParser; import org.apache.commons.cli.GnuParser; import org.apache.commons.cli.HelpFormatter; import org.apache.commons.cli.Option; import org.apache.commons.cli.OptionBuilder; import org.apache.commons.cli.Options; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.conf.Configured; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.FloatWritable; import org.apache.hadoop.io.Text; import org.apache.hadoop.io.WritableUtils; import org.apache.hadoop.mapred.FileInputFormat; import org.apache.hadoop.mapred.FileOutputFormat; import org.apache.hadoop.mapred.JobClient; import org.apache.hadoop.mapred.JobConf; import org.apache.hadoop.mapred.Mapper; import org.apache.hadoop.mapred.OutputCollector; import org.apache.hadoop.mapred.Reducer; import org.apache.hadoop.mapred.Reporter; import org.apache.hadoop.mapred.SequenceFileInputFormat; import org.apache.hadoop.mapred.SequenceFileOutputFormat; import org.apache.hadoop.mapred.TextOutputFormat; import org.apache.hadoop.util.StringUtils; import org.apache.hadoop.util.Tool; import org.apache.hadoop.util.ToolRunner; import org.apache.nutch.util.NutchConfiguration; import org.apache.nutch.util.NutchJob; import org.apache.nutch.util.TimingUtil; import org.apache.nutch.util.URLUtil; /** * A tools that dumps out the top urls by number of inlinks, number of outlinks, * or by score, to a text file. One of the major uses of this tool is to check * the top scoring urls of a link analysis program such as LinkRank. * * For number of inlinks or number of outlinks the WebGraph program will need to * have been run. For link analysis score a program such as LinkRank will need * to have been run which updates the NodeDb of the WebGraph. */ public class NodeDumper extends Configured implements Tool { public static final Logger LOG = LoggerFactory.getLogger(NodeDumper.class); private static enum DumpType { INLINKS, OUTLINKS, SCORES } private static enum AggrType { SUM, MAX } private static enum NameType { HOST, DOMAIN } /** * Outputs the top urls sorted in descending order. Depending on the flag set * on the command line, the top urls could be for number of inlinks, for * number of outlinks, or for link analysis score. */ public static class Sorter extends Configured implements Mapper<Text, Node, FloatWritable, Text>, Reducer<FloatWritable, Text, Text, FloatWritable> { private JobConf conf; private boolean inlinks = false; private boolean outlinks = false; private boolean scores = false; private long topn = Long.MAX_VALUE; /** * Configures the job, sets the flag for type of content and the topN number * if any. */ public void configure(JobConf conf) { this.conf = conf; this.inlinks = conf.getBoolean("inlinks", false); this.outlinks = conf.getBoolean("outlinks", false); this.scores = conf.getBoolean("scores", true); this.topn = conf.getLong("topn", Long.MAX_VALUE); } public void close() { } /** * Outputs the url with the appropriate number of inlinks, outlinks, or for * score. */ public void map(Text key, Node node, OutputCollector<FloatWritable, Text> output, Reporter reporter) throws IOException { float number = 0; if (inlinks) { number = node.getNumInlinks(); } else if (outlinks) { number = node.getNumOutlinks(); } else { number = node.getInlinkScore(); } // number collected with negative to be descending output.collect(new FloatWritable(-number), key); } /** * Flips and collects the url and numeric sort value. */ public void reduce(FloatWritable key, Iterator<Text> values, OutputCollector<Text, FloatWritable> output, Reporter reporter) throws IOException { // take the negative of the negative to get original value, sometimes 0 // value are a little weird float val = key.get(); FloatWritable number = new FloatWritable(val == 0 ? 0 : -val); long numCollected = 0; // collect all values, this time with the url as key while (values.hasNext() && (numCollected < topn)) { Text url = WritableUtils.clone(values.next(), conf); output.collect(url, number); numCollected++; } } } /** * Outputs the hosts or domains with an associated value. This value consists of either * the number of inlinks, the number of outlinks or the score. The computed value is then * either the sum of all parts or the top value. */ public static class Dumper extends Configured implements Mapper<Text, Node, Text, FloatWritable>, Reducer<Text, FloatWritable, Text, FloatWritable> { private JobConf conf; private boolean inlinks = false; private boolean outlinks = false; private boolean scores = false; private long topn = Long.MAX_VALUE; private boolean host = false; private boolean domain = false; private boolean sum = false; private boolean max = false; public void configure(JobConf conf) { this.conf = conf; this.inlinks = conf.getBoolean("inlinks", false); this.outlinks = conf.getBoolean("outlinks", false); this.scores = conf.getBoolean("scores", true); this.topn = conf.getLong("topn", Long.MAX_VALUE); this.host = conf.getBoolean("host", false); this.domain = conf.getBoolean("domain", false); this.sum = conf.getBoolean("sum", false); this.max = conf.getBoolean("max", false); } public void close() { } /** * Outputs the host or domain as key for this record and numInlinks, numOutlinks * or score as the value. */ public void map(Text key, Node node, OutputCollector<Text, FloatWritable> output, Reporter reporter) throws IOException { float number = 0; if (inlinks) { number = node.getNumInlinks(); } else if (outlinks) { number = node.getNumOutlinks(); } else { number = node.getInlinkScore(); } if (host) { key.set(URLUtil.getHost(key.toString())); } else { key.set(URLUtil.getDomainName(key.toString())); } output.collect(key, new FloatWritable(number)); } /** * Outputs either the sum or the top value for this record. */ public void reduce(Text key, Iterator<FloatWritable> values, OutputCollector<Text, FloatWritable> output, Reporter reporter) throws IOException { long numCollected = 0; float sumOrMax = 0; float val = 0; // collect all values, this time with the url as key while (values.hasNext() && (numCollected < topn)) { val = values.next().get(); if (sum) { sumOrMax += val; } else { if (sumOrMax < val) { sumOrMax = val; } } numCollected++; } output.collect(key, new FloatWritable(sumOrMax)); } } /** * Runs the process to dump the top urls out to a text file. * * @param webGraphDb The WebGraph from which to pull values. * * @param topN * @param output * * @throws IOException If an error occurs while dumping the top values. */ public void dumpNodes(Path webGraphDb, DumpType type, long topN, Path output, boolean asEff, NameType nameType, AggrType aggrType, boolean asSequenceFile) throws Exception { SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); long start = System.currentTimeMillis(); LOG.info("NodeDumper: starting at " + sdf.format(start)); Path nodeDb = new Path(webGraphDb, WebGraph.NODE_DIR); Configuration conf = getConf(); JobConf dumper = new NutchJob(conf); dumper.setJobName("NodeDumper: " + webGraphDb); FileInputFormat.addInputPath(dumper, nodeDb); dumper.setInputFormat(SequenceFileInputFormat.class); if (nameType == null) { dumper.setMapperClass(Sorter.class); dumper.setReducerClass(Sorter.class); dumper.setMapOutputKeyClass(FloatWritable.class); dumper.setMapOutputValueClass(Text.class); } else { dumper.setMapperClass(Dumper.class); dumper.setReducerClass(Dumper.class); dumper.setMapOutputKeyClass(Text.class); dumper.setMapOutputValueClass(FloatWritable.class); } dumper.setOutputKeyClass(Text.class); dumper.setOutputValueClass(FloatWritable.class); FileOutputFormat.setOutputPath(dumper, output); if (asSequenceFile) { dumper.setOutputFormat(SequenceFileOutputFormat.class); } else { dumper.setOutputFormat(TextOutputFormat.class); } dumper.setNumReduceTasks(1); dumper.setBoolean("inlinks", type == DumpType.INLINKS); dumper.setBoolean("outlinks", type == DumpType.OUTLINKS); dumper.setBoolean("scores", type == DumpType.SCORES); dumper.setBoolean("host", nameType == NameType.HOST); dumper.setBoolean("domain", nameType == NameType.DOMAIN); dumper.setBoolean("sum", aggrType == AggrType.SUM); dumper.setBoolean("max", aggrType == AggrType.MAX); dumper.setLong("topn", topN); // Set equals-sign as separator for Solr's ExternalFileField if (asEff) { dumper.set("mapred.textoutputformat.separator", "="); } try { LOG.info("NodeDumper: running"); JobClient.runJob(dumper); } catch (IOException e) { LOG.error(StringUtils.stringifyException(e)); throw e; } long end = System.currentTimeMillis(); LOG.info("NodeDumper: finished at " + sdf.format(end) + ", elapsed: " + TimingUtil.elapsedTime(start, end)); } public static void main(String[] args) throws Exception { int res = ToolRunner.run(NutchConfiguration.create(), new NodeDumper(), args); System.exit(res); } /** * Runs the node dumper tool. */ public int run(String[] args) throws Exception { Options options = new Options(); Option helpOpts = OptionBuilder.withArgName("help").withDescription("show this help message") .create("help"); Option webGraphDbOpts = OptionBuilder.withArgName("webgraphdb").hasArg() .withDescription("the web graph database to use").create("webgraphdb"); Option inlinkOpts = OptionBuilder.withArgName("inlinks").withDescription("show highest inlinks") .create("inlinks"); Option outlinkOpts = OptionBuilder.withArgName("outlinks").withDescription("show highest outlinks") .create("outlinks"); Option scoreOpts = OptionBuilder.withArgName("scores").withDescription("show highest scores") .create("scores"); Option topNOpts = OptionBuilder.withArgName("topn").hasOptionalArg().withDescription("show topN scores") .create("topn"); Option outputOpts = OptionBuilder.withArgName("output").hasArg() .withDescription("the output directory to use").create("output"); Option effOpts = OptionBuilder.withArgName("asEff") .withDescription("Solr ExternalFileField compatible output format").create("asEff"); Option groupOpts = OptionBuilder.hasArgs(2).withDescription("group <host|domain> <sum|max>") .create("group"); Option sequenceFileOpts = OptionBuilder.withArgName("asSequenceFile") .withDescription("whether to output as a sequencefile").create("asSequenceFile"); options.addOption(helpOpts); options.addOption(webGraphDbOpts); options.addOption(inlinkOpts); options.addOption(outlinkOpts); options.addOption(scoreOpts); options.addOption(topNOpts); options.addOption(outputOpts); options.addOption(effOpts); options.addOption(groupOpts); options.addOption(sequenceFileOpts); CommandLineParser parser = new GnuParser(); try { CommandLine line = parser.parse(options, args); if (line.hasOption("help") || !line.hasOption("webgraphdb")) { HelpFormatter formatter = new HelpFormatter(); formatter.printHelp("NodeDumper", options); return -1; } String webGraphDb = line.getOptionValue("webgraphdb"); boolean inlinks = line.hasOption("inlinks"); boolean outlinks = line.hasOption("outlinks"); boolean scores = line.hasOption("scores"); long topN = (line.hasOption("topn") ? Long.parseLong(line.getOptionValue("topn")) : Long.MAX_VALUE); // get the correct dump type String output = line.getOptionValue("output"); DumpType type = (inlinks ? DumpType.INLINKS : outlinks ? DumpType.OUTLINKS : DumpType.SCORES); NameType nameType = null; AggrType aggrType = null; String[] group = line.getOptionValues("group"); if (group != null && group.length == 2) { nameType = (group[0].equals("host") ? NameType.HOST : group[0].equals("domain") ? NameType.DOMAIN : null); aggrType = (group[1].equals("sum") ? AggrType.SUM : group[1].equals("sum") ? AggrType.MAX : null); } // Use ExternalFileField? boolean asEff = line.hasOption("asEff"); boolean asSequenceFile = line.hasOption("asSequenceFile"); dumpNodes(new Path(webGraphDb), type, topN, new Path(output), asEff, nameType, aggrType, asSequenceFile); return 0; } catch (Exception e) { LOG.error("NodeDumper: " + StringUtils.stringifyException(e)); return -2; } } }