/**
* 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.crawl;
import java.io.*;
import java.text.SimpleDateFormat;
import java.util.*;
// Commons Logging imports
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hadoop.io.*;
import org.apache.hadoop.fs.*;
import org.apache.hadoop.conf.*;
import org.apache.hadoop.mapred.*;
import org.apache.hadoop.util.*;
import org.apache.nutch.util.HadoopFSUtil;
import org.apache.nutch.util.LockUtil;
import org.apache.nutch.util.NutchConfiguration;
import org.apache.nutch.util.NutchJob;
import org.apache.nutch.util.TimingUtil;
/**
* This class takes the output of the fetcher and updates the
* crawldb accordingly.
*/
public class CrawlDb extends Configured implements Tool {
public static final Logger LOG = LoggerFactory.getLogger(CrawlDb.class);
public static final String CRAWLDB_ADDITIONS_ALLOWED = "db.update.additions.allowed";
public static final String CRAWLDB_PURGE_404 = "db.update.purge.404";
public static final String CURRENT_NAME = "current";
public static final String LOCK_NAME = ".locked";
public CrawlDb() {}
public CrawlDb(Configuration conf) {
setConf(conf);
}
public void update(Path crawlDb, Path[] segments, boolean normalize, boolean filter) throws IOException {
boolean additionsAllowed = getConf().getBoolean(CRAWLDB_ADDITIONS_ALLOWED, true);
update(crawlDb, segments, normalize, filter, additionsAllowed, false);
}
public void update(Path crawlDb, Path[] segments, boolean normalize, boolean filter, boolean additionsAllowed, boolean force) throws IOException {
FileSystem fs = FileSystem.get(getConf());
Path lock = new Path(crawlDb, LOCK_NAME);
LockUtil.createLockFile(fs, lock, force);
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
long start = System.currentTimeMillis();
JobConf job = CrawlDb.createJob(getConf(), crawlDb);
job.setBoolean(CRAWLDB_ADDITIONS_ALLOWED, additionsAllowed);
job.setBoolean(CrawlDbFilter.URL_FILTERING, filter);
job.setBoolean(CrawlDbFilter.URL_NORMALIZING, normalize);
boolean url404Purging = job.getBoolean(CRAWLDB_PURGE_404, false);
if (LOG.isInfoEnabled()) {
LOG.info("CrawlDb update: starting at " + sdf.format(start));
LOG.info("CrawlDb update: db: " + crawlDb);
LOG.info("CrawlDb update: segments: " + Arrays.asList(segments));
LOG.info("CrawlDb update: additions allowed: " + additionsAllowed);
LOG.info("CrawlDb update: URL normalizing: " + normalize);
LOG.info("CrawlDb update: URL filtering: " + filter);
LOG.info("CrawlDb update: 404 purging: " + url404Purging);
}
for (int i = 0; i < segments.length; i++) {
Path fetch = new Path(segments[i], CrawlDatum.FETCH_DIR_NAME);
Path parse = new Path(segments[i], CrawlDatum.PARSE_DIR_NAME);
if (fs.exists(fetch) && fs.exists(parse)) {
FileInputFormat.addInputPath(job, fetch);
FileInputFormat.addInputPath(job, parse);
} else {
LOG.info(" - skipping invalid segment " + segments[i]);
}
}
if (LOG.isInfoEnabled()) {
LOG.info("CrawlDb update: Merging segment data into db.");
}
try {
JobClient.runJob(job);
} catch (IOException e) {
LockUtil.removeLockFile(fs, lock);
Path outPath = FileOutputFormat.getOutputPath(job);
if (fs.exists(outPath) ) fs.delete(outPath, true);
throw e;
}
CrawlDb.install(job, crawlDb);
long end = System.currentTimeMillis();
LOG.info("CrawlDb update: finished at " + sdf.format(end) + ", elapsed: " + TimingUtil.elapsedTime(start, end));
}
/*
* Configure a new CrawlDb in a temp folder at crawlDb/<rand>
*/
public static JobConf createJob(Configuration config, Path crawlDb)
throws IOException {
Path newCrawlDb =
new Path(crawlDb,
Integer.toString(new Random().nextInt(Integer.MAX_VALUE)));
JobConf job = new NutchJob(config);
job.setJobName("crawldb " + crawlDb);
Path current = new Path(crawlDb, CURRENT_NAME);
if (FileSystem.get(job).exists(current)) {
FileInputFormat.addInputPath(job, current);
}
job.setInputFormat(SequenceFileInputFormat.class);
job.setMapperClass(CrawlDbFilter.class);
job.setReducerClass(CrawlDbReducer.class);
FileOutputFormat.setOutputPath(job, newCrawlDb);
job.setOutputFormat(MapFileOutputFormat.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(CrawlDatum.class);
// https://issues.apache.org/jira/browse/NUTCH-1110
job.setBoolean("mapreduce.fileoutputcommitter.marksuccessfuljobs", false);
return job;
}
public static void install(JobConf job, Path crawlDb) throws IOException {
boolean preserveBackup = job.getBoolean("db.preserve.backup", true);
Path newCrawlDb = FileOutputFormat.getOutputPath(job);
FileSystem fs = new JobClient(job).getFs();
Path old = new Path(crawlDb, "old");
Path current = new Path(crawlDb, CURRENT_NAME);
if (fs.exists(current)) {
if (fs.exists(old)) fs.delete(old, true);
fs.rename(current, old);
}
fs.mkdirs(crawlDb);
fs.rename(newCrawlDb, current);
if (!preserveBackup && fs.exists(old)) fs.delete(old, true);
Path lock = new Path(crawlDb, LOCK_NAME);
LockUtil.removeLockFile(fs, lock);
}
public static void main(String[] args) throws Exception {
int res = ToolRunner.run(NutchConfiguration.create(), new CrawlDb(), args);
System.exit(res);
}
public int run(String[] args) throws Exception {
if (args.length < 1) {
System.err.println("Usage: CrawlDb <crawldb> (-dir <segments> | <seg1> <seg2> ...) [-force] [-normalize] [-filter] [-noAdditions]");
System.err.println("\tcrawldb\tCrawlDb to update");
System.err.println("\t-dir segments\tparent directory containing all segments to update from");
System.err.println("\tseg1 seg2 ...\tlist of segment names to update from");
System.err.println("\t-force\tforce update even if CrawlDb appears to be locked (CAUTION advised)");
System.err.println("\t-normalize\tuse URLNormalizer on urls in CrawlDb and segment (usually not needed)");
System.err.println("\t-filter\tuse URLFilters on urls in CrawlDb and segment");
System.err.println("\t-noAdditions\tonly update already existing URLs, don't add any newly discovered URLs");
return -1;
}
boolean normalize = getConf().getBoolean(CrawlDbFilter.URL_NORMALIZING, false);
boolean filter = getConf().getBoolean(CrawlDbFilter.URL_FILTERING, false);
boolean additionsAllowed = getConf().getBoolean(CRAWLDB_ADDITIONS_ALLOWED, true);
boolean force = false;
final FileSystem fs = FileSystem.get(getConf());
HashSet<Path> dirs = new HashSet<Path>();
for (int i = 1; i < args.length; i++) {
if (args[i].equals("-normalize")) {
normalize = true;
} else if (args[i].equals("-filter")) {
filter = true;
} else if (args[i].equals("-force")) {
force = true;
} else if (args[i].equals("-noAdditions")) {
additionsAllowed = false;
} else if (args[i].equals("-dir")) {
FileStatus[] paths = fs.listStatus(new Path(args[++i]), HadoopFSUtil.getPassDirectoriesFilter(fs));
dirs.addAll(Arrays.asList(HadoopFSUtil.getPaths(paths)));
} else {
dirs.add(new Path(args[i]));
}
}
try {
update(new Path(args[0]), dirs.toArray(new Path[dirs.size()]), normalize, filter, additionsAllowed, force);
return 0;
} catch (Exception e) {
LOG.error("CrawlDb update: " + StringUtils.stringifyException(e));
return -1;
}
}
}