/**
* 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.util.ArrayList;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.util.StringUtils;
import org.apache.nutch.crawl.CrawlDatum;
import static org.apache.nutch.crawl.CrawlDatum.*;
import org.apache.nutch.scoring.ScoringFilterException;
import org.apache.nutch.scoring.ScoringFilters;
import static org.junit.Assert.*;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Test transitions of {@link CrawlDatum} states during an update of
* {@link CrawlDb} (command {@literal updatedb}):
* <ul>
* <li>simulate updatedb with the old CrawlDatum (db status) and the new one
* (fetch status) and test whether the resulting CrawlDatum has the appropriate
* status.</li>
* <li>also check for further CrawlDatum fields (signature, etc.)</li>
* <li>and additional conditions:</li>
* <ul>
* <li>retry counters</li>
* <li>signatures</li>
* <li>configuration properties</li>
* <li>(additional) CrawlDatums of status linked (stemming from inlinks)</li>
* </ul>
* </li>
* </ul>
*/
public class TestCrawlDbStates {
private static final Logger LOG = LoggerFactory.getLogger(TestCrawlDbStates.class);
protected static final byte[][] fetchDbStatusPairs = {
{ -1, STATUS_DB_UNFETCHED },
{ STATUS_FETCH_SUCCESS, STATUS_DB_FETCHED },
{ STATUS_FETCH_GONE, STATUS_DB_GONE },
{ STATUS_FETCH_REDIR_TEMP, STATUS_DB_REDIR_TEMP },
{ STATUS_FETCH_REDIR_PERM, STATUS_DB_REDIR_PERM },
{ STATUS_FETCH_NOTMODIFIED, STATUS_DB_NOTMODIFIED },
{ STATUS_FETCH_RETRY, -1 }, // fetch_retry does not have a CrawlDb counter-part
{ -1, STATUS_DB_DUPLICATE },
};
/** tested {@link FetchSchedule} implementations */
protected String[] schedules = {"DefaultFetchSchedule", "AdaptiveFetchSchedule"};
/** CrawlDatum as result of a link */
protected final CrawlDatum linked = new CrawlDatum(STATUS_LINKED,
CrawlDBTestUtil.createConfiguration().getInt("db.fetch.interval.default",
2592000), 0.1f);
/**
* Test the matrix of state transitions:
* <ul>
* <li>for all available {@link FetchSchedule} implementations</li>
* <li>for every possible status in CrawlDb (including "not in CrawlDb")</li>
* <li>for every possible fetch status</li>
* <li>and zero or more (0-3) additional in-links</li>
* </ul>
* call {@literal updatedb} and check whether the resulting CrawlDb status is
* the expected one.
*/
@Test
public void testCrawlDbStateTransitionMatrix() {
LOG.info("Test CrawlDatum state transitions");
Configuration conf = CrawlDBTestUtil.createConfiguration();
CrawlDbUpdateUtil<CrawlDbReducer> updateDb = new CrawlDbUpdateUtil<CrawlDbReducer>(
new CrawlDbReducer(), conf);
int retryMax = conf.getInt("db.fetch.retry.max", 3);
for (String sched : schedules) {
LOG.info("Testing state transitions with " + sched);
conf.set("db.fetch.schedule.class", "org.apache.nutch.crawl."+sched);
FetchSchedule schedule = FetchScheduleFactory
.getFetchSchedule(new JobConf(conf));
for (int i = 0; i < fetchDbStatusPairs.length; i++) {
byte fromDbStatus = fetchDbStatusPairs[i][1];
for (int j = 0; j < fetchDbStatusPairs.length; j++) {
byte fetchStatus = fetchDbStatusPairs[j][0];
CrawlDatum fromDb = null;
if (fromDbStatus == -1) {
// nothing yet in CrawlDb
// CrawlDatum added by FreeGenerator or via outlink
} else {
fromDb = new CrawlDatum();
fromDb.setStatus(fromDbStatus);
// initialize fetchInterval:
schedule.initializeSchedule(CrawlDbUpdateUtil.dummyURL, fromDb);
}
// expected db status
byte toDbStatus = fetchDbStatusPairs[j][1];
if (fetchStatus == -1) {
if (fromDbStatus == -1) {
// nothing fetched yet: new document detected via outlink
toDbStatus = STATUS_DB_UNFETCHED;
} else {
// nothing fetched but new inlinks detected: status is unchanged
toDbStatus = fromDbStatus;
}
} else if (fetchStatus == STATUS_FETCH_RETRY) {
// a simple test of fetch_retry (without retries)
if (fromDb == null || fromDb.getRetriesSinceFetch() < retryMax) {
toDbStatus = STATUS_DB_UNFETCHED;
} else {
toDbStatus = STATUS_DB_GONE;
}
}
String fromDbStatusName = (fromDbStatus == -1 ? "<not in CrawlDb>"
: getStatusName(fromDbStatus));
String fetchStatusName = (fetchStatus == -1 ? "<only inlinks>" : CrawlDatum
.getStatusName(fetchStatus));
LOG.info(fromDbStatusName + " + " + fetchStatusName + " => "
+ getStatusName(toDbStatus));
List<CrawlDatum> values = new ArrayList<CrawlDatum>();
for (int l = 0; l <= 2; l++) { // number of additional in-links
CrawlDatum fetch = null;
if (fetchStatus == -1) {
// nothing fetched, need at least one in-link
if (l == 0) continue;
} else {
fetch = new CrawlDatum();
if (fromDb != null) {
fetch.set(fromDb);
} else {
// not yet in CrawlDb: added by FreeGenerator
schedule.initializeSchedule(CrawlDbUpdateUtil.dummyURL, fetch);
}
fetch.setStatus(fetchStatus);
fetch.setFetchTime(System.currentTimeMillis());
}
if (fromDb != null)
values.add(fromDb);
if (fetch != null)
values.add(fetch);
for (int n = 0; n < l; n++) {
values.add(linked);
}
List<CrawlDatum> res = updateDb.update(values);
if (res.size() != 1) {
fail("CrawlDb update didn't result in one single CrawlDatum per URL");
continue;
}
byte status = res.get(0).getStatus();
if (status != toDbStatus) {
fail("CrawlDb update for " + fromDbStatusName + " and "
+ fetchStatusName + " and " + l + " inlinks results in "
+ getStatusName(status) + " (expected: "
+ getStatusName(toDbStatus) + ")");
}
values.clear();
}
}
}
}
}
/**
* Test states after inject: inject must not modify the status of CrawlDatums
* already in CrawlDb. Newly injected elements have status "db_unfetched".
* Inject is simulated by calling {@link Injector.InjectReducer#reduce()}.
*/
@Test
public void testCrawlDbStatTransitionInject() {
LOG.info("Test CrawlDatum states in Injector after inject");
Configuration conf = CrawlDBTestUtil.createConfiguration();
CrawlDbUpdateUtil<Injector.InjectReducer> inject = new CrawlDbUpdateUtil<Injector.InjectReducer>(
new Injector.InjectReducer(), conf);
ScoringFilters scfilters = new ScoringFilters(conf);
for (String sched : schedules) {
LOG.info("Testing inject with " + sched);
conf.set("db.fetch.schedule.class", "org.apache.nutch.crawl."+sched);
FetchSchedule schedule = FetchScheduleFactory
.getFetchSchedule(new JobConf(conf));
List<CrawlDatum> values = new ArrayList<CrawlDatum>();
for (int i = 0; i < fetchDbStatusPairs.length; i++) {
byte fromDbStatus = fetchDbStatusPairs[i][1];
byte toDbStatus = fromDbStatus;
if (fromDbStatus == -1) {
toDbStatus = STATUS_DB_UNFETCHED;
} else {
CrawlDatum fromDb = new CrawlDatum();
fromDb.setStatus(fromDbStatus);
schedule.initializeSchedule(CrawlDbUpdateUtil.dummyURL, fromDb);
values.add(fromDb);
}
LOG.info("inject "
+ (fromDbStatus == -1 ? "<not in CrawlDb>" : CrawlDatum
.getStatusName(fromDbStatus)) + " + "
+ getStatusName(STATUS_INJECTED) + " => "
+ getStatusName(toDbStatus));
CrawlDatum injected = new CrawlDatum(STATUS_INJECTED,
conf.getInt("db.fetch.interval.default", 2592000), 0.1f);
schedule.initializeSchedule(CrawlDbUpdateUtil.dummyURL, injected);
try {
scfilters.injectedScore(CrawlDbUpdateUtil.dummyURL, injected);
} catch (ScoringFilterException e) {
LOG.error(StringUtils.stringifyException(e));
}
values.add(injected);
List<CrawlDatum> res = inject.update(values);
if (res.size() != 1) {
fail("Inject didn't result in one single CrawlDatum per URL");
continue;
}
byte status = res.get(0).getStatus();
if (status != toDbStatus) {
fail("Inject for "
+ (fromDbStatus == -1 ? "" : getStatusName(fromDbStatus) + " and ")
+ getStatusName(STATUS_INJECTED)
+ " results in " + getStatusName(status)
+ " (expected: " + getStatusName(toDbStatus) + ")");
}
values.clear();
}
}
}
/**
* Test status db_notmodified detected by
* <ul>
* <li>signature comparison</li>
* <li>or HTTP 304</li>
* </ul>
* In addition, test for all available {@link FetchSchedule} implementations
* whether
* <ul>
* <li>modified time is set</li>
* <li>re-fetch is triggered after a certain time to force the fetched content
* to be in a recent segment (old segments are deleted, see comments in
* {@link CrawlDbReducer#reduce(Text, Iterator, OutputCollector, Reporter)}
* </li>
* </ul>
*/
@Test
public void testCrawlDbReducerNotModified() {
LOG.info("Test state notmodified");
Configuration conf = CrawlDBTestUtil.createConfiguration();
// test not modified detected by signature comparison
for (String sched : schedules) {
String desc = "test notmodified by signature comparison + " + sched;
LOG.info(desc);
conf.set("db.fetch.schedule.class", "org.apache.nutch.crawl."+sched);
ContinuousCrawlTestUtil crawlUtil = new CrawlTestFetchNotModified(conf);
if (!crawlUtil.run(20)) {
fail("failed: " + desc);
}
}
// test not modified detected by HTTP 304
for (String sched : schedules) {
String desc = "test notmodified by HTTP 304 + " + sched;
LOG.info(desc);
conf.set("db.fetch.schedule.class", "org.apache.nutch.crawl."+sched);
ContinuousCrawlTestUtil crawlUtil = new CrawlTestFetchNotModifiedHttp304(conf);
if (!crawlUtil.run(20)) {
fail("failed: " + desc);
}
}
}
protected class CrawlTestFetchNotModified extends ContinuousCrawlTestUtil {
/** time of the current fetch */
protected long currFetchTime;
/** time the last fetch took place */
protected long lastFetchTime;
/** time the document was fetched first (at all or after it has been changed) */
protected long firstFetchTime;
/** state in CrawlDb before the last fetch */
protected byte previousDbState;
/** signature in CrawlDb of previous fetch */
protected byte[] lastSignature;
private long maxFetchInterval;
private FetchSchedule schedule;
CrawlTestFetchNotModified(Configuration conf) {
super(conf);
maxFetchInterval = conf.getLong("db.fetch.interval.max", 7776000); // default = 90 days
maxFetchInterval += (24*60*60); // but take one day more to avoid false alarms
maxFetchInterval *= 1000; // in milli-seconds
schedule = FetchScheduleFactory.getFetchSchedule(new JobConf(conf));
}
@Override
protected boolean check(CrawlDatum result) {
if (lastFetchTime > 0 && (currFetchTime - lastFetchTime) > maxFetchInterval) {
LOG.error("last effective fetch (HTTP 200, not HTTP 304), at "
+ new Date(lastFetchTime)
+ ", took place more than db.fetch.interval.max time, "
+ "segment containing fetched content may have been deleted");
return false;
}
switch (result.getStatus()) {
case STATUS_DB_NOTMODIFIED:
// db_notmodified is correct if the document has been fetched previously
// and it has not been changed since
if ((previousDbState == STATUS_DB_FETCHED || previousDbState == STATUS_DB_NOTMODIFIED)) {
if (lastSignature != null
&& result.getSignature() != null
&& SignatureComparator._compare(lastSignature,
result.getSignature()) != 0) {
LOG.error("document has changed (signature changed) but state is still "
+ getStatusName(STATUS_DB_NOTMODIFIED));
return false;
}
LOG.info("ok: " + result);
return checkModifiedTime(result, firstFetchTime);
}
LOG.warn("notmodified without previous fetch");
break;
case STATUS_DB_FETCHED:
if (previousDbState == STATUS_DB_UNFETCHED) {
LOG.info("ok (first fetch): " + result);
return checkModifiedTime(result, firstFetchTime);
} else if (lastSignature != null
&& result.getSignature() != null
&& SignatureComparator._compare(lastSignature,
result.getSignature()) != 0) {
LOG.info("ok (content changed): " + result);
// expect modified time == now
return checkModifiedTime(result, currFetchTime);
} else {
LOG.warn("document has not changed, db_notmodified expected");
}
break;
case STATUS_DB_UNFETCHED:
/**
* Status db_unfetched is possible with {@link AdaptiveFetchSchedule}
* because {@link CrawlDbReducer#reduce} calls
* {@link FetchSchedule#forceRefetch} to force a re-fetch if fetch
* interval grows too large.
*/
if (schedule.getClass() == AdaptiveFetchSchedule.class) {
LOG.info("state set to unfetched by AdaptiveFetchSchedule");
if (result.getSignature() != null) {
LOG.warn("must reset signature: " + result);
return false;
}
LOG.info("ok: " + result);
firstFetchTime = 0;
return true;
}
}
LOG.warn("wrong result: " + result);
return false;
}
// test modified time
private boolean checkModifiedTime(CrawlDatum result, long modifiedTime) {
if (result.getModifiedTime() == 0) {
LOG.error("modified time not set (TODO: not set by DefaultFetchSchedule)");
// TODO: return false (but DefaultFetchSchedule does not set modified
// time, see NUTCH-933)
return true;
} else if (modifiedTime == result.getModifiedTime()) {
return true;
}
LOG.error("wrong modified time: " + new Date(result.getModifiedTime())
+ " (expected " + new Date(modifiedTime) + ")");
return false;
}
@Override
protected CrawlDatum fetch(CrawlDatum datum, long currentTime) {
lastFetchTime = currFetchTime;
currFetchTime = currentTime;
previousDbState = datum.getStatus();
lastSignature = datum.getSignature();
datum = super.fetch(datum, currentTime);
if (firstFetchTime == 0) {
firstFetchTime = currFetchTime;
} else if ((currFetchTime - firstFetchTime) > (duration/2)) {
// simulate a modification after "one year"
changeContent();
firstFetchTime = currFetchTime;
}
return datum;
}
}
protected class CrawlTestFetchNotModifiedHttp304 extends CrawlTestFetchNotModified {
CrawlTestFetchNotModifiedHttp304(Configuration conf) {
super(conf);
}
@Override
protected CrawlDatum fetch(CrawlDatum datum, long currentTime) {
lastFetchTime = currFetchTime;
currFetchTime = currentTime;
previousDbState = datum.getStatus();
lastSignature = datum.getSignature();
int httpCode;
/* document is "really" fetched (no HTTP 304)
* - if last-modified time or signature are unset
* (page has not been fetched before or fetch is forced)
* - for test purposes, we simulate a modified after "one year"
*/
if (datum.getModifiedTime() == 0 && datum.getSignature() == null
|| (currFetchTime - firstFetchTime) > (duration/2)) {
firstFetchTime = currFetchTime;
httpCode = 200;
datum.setStatus(STATUS_FETCH_SUCCESS);
// modify content to change signature
changeContent();
} else {
httpCode = 304;
datum.setStatus(STATUS_FETCH_NOTMODIFIED);
}
LOG.info("fetched with HTTP " + httpCode + " => "
+ getStatusName(datum.getStatus()));
datum.setFetchTime(currentTime);
return datum;
}
}
/**
* NUTCH-1245: a fetch_gone should always result in a db_gone.
* <p>
* Even in a long-running continuous crawl, when a gone page is
* re-fetched several times over time.
* </p>
*/
@Test
public void testCrawlDbReducerPageGoneSchedule1() {
LOG.info("NUTCH-1245: test long running continuous crawl");
ContinuousCrawlTestUtil crawlUtil = new ContinuousCrawlTestUtil(
STATUS_FETCH_GONE, STATUS_DB_GONE);
if (!crawlUtil.run(20)) {
fail("fetch_gone did not result in a db_gone (NUTCH-1245)");
}
}
/**
* NUTCH-1245: a fetch_gone should always result in a db_gone.
* <p>
* As some kind of misconfiguration set db.fetch.interval.default to a value
* > (fetchIntervalMax * 1.5).
* </p>
*/
@Test
public void testCrawlDbReducerPageGoneSchedule2() {
LOG.info("NUTCH-1245 (misconfiguration): test with db.fetch.interval.default > (1.5 * db.fetch.interval.max)");
Configuration conf = CrawlDBTestUtil.createConfiguration();
int fetchIntervalMax = conf.getInt("db.fetch.interval.max", 0);
conf.setInt("db.fetch.interval.default",
3 + (int) (fetchIntervalMax * 1.5));
ContinuousCrawlTestUtil crawlUtil = new ContinuousCrawlTestUtil(conf,
STATUS_FETCH_GONE, STATUS_DB_GONE);
if (!crawlUtil.run(0)) {
fail("fetch_gone did not result in a db_gone (NUTCH-1245)");
}
}
/**
* Test whether signatures are reset for "content-less" states
* (gone, redirect, etc.): otherwise, if this state is temporary
* and the document appears again with the old content, it may
* get marked as not_modified in CrawlDb just after the redirect
* state. In this case we cannot expect content in segments.
* Cf. NUTCH-1422: reset signature for redirects.
*/
// TODO: can only test if solution is done in CrawlDbReducer
@Test
public void testSignatureReset() {
LOG.info("NUTCH-1422 must reset signature for redirects and similar states");
Configuration conf = CrawlDBTestUtil.createConfiguration();
for (String sched : schedules) {
LOG.info("Testing reset signature with " + sched);
conf.set("db.fetch.schedule.class", "org.apache.nutch.crawl."+sched);
ContinuousCrawlTestUtil crawlUtil = new CrawlTestSignatureReset(conf);
if (!crawlUtil.run(20)) {
fail("failed: signature not reset");
}
}
}
private class CrawlTestSignatureReset extends ContinuousCrawlTestUtil {
byte[][] noContentStates = {
{ STATUS_FETCH_GONE, STATUS_DB_GONE },
{ STATUS_FETCH_REDIR_TEMP, STATUS_DB_REDIR_TEMP },
{ STATUS_FETCH_REDIR_PERM, STATUS_DB_REDIR_PERM } };
int counter = 0;
byte fetchState;
public CrawlTestSignatureReset(Configuration conf) {
super(conf);
}
@Override
protected CrawlDatum fetch(CrawlDatum datum, long currentTime) {
datum = super.fetch(datum, currentTime);
counter++;
// flip-flopping between successful fetch and one of content-less states
if (counter%2 == 1) {
fetchState = STATUS_FETCH_SUCCESS;
} else {
fetchState = noContentStates[(counter%6)/2][0];
}
LOG.info("Step " + counter + ": fetched with "
+ getStatusName(fetchState));
datum.setStatus(fetchState);
return datum;
}
@Override
protected boolean check(CrawlDatum result) {
if (result.getStatus() == STATUS_DB_NOTMODIFIED
&& !(fetchState == STATUS_FETCH_SUCCESS || fetchState == STATUS_FETCH_NOTMODIFIED)) {
LOG.error("Should never get into state "
+ getStatusName(STATUS_DB_NOTMODIFIED) + " from "
+ getStatusName(fetchState));
return false;
}
if (result.getSignature() != null
&& !(result.getStatus() == STATUS_DB_FETCHED || result.getStatus() == STATUS_DB_NOTMODIFIED)) {
LOG.error("Signature not reset in state "
+ getStatusName(result.getStatus()));
// ok here: since it's not the problem itself (the db_notmodified), but
// the reason for it
}
return true;
}
}
}