private FetchItem queueRedirect(Text redirUrl, FetchItem fit) throws ScoringFilterException {
CrawlDatum newDatum =
new CrawlDatum(
CrawlDatum.STATUS_DB_UNFETCHED, fit.datum.getFetchInterval(), fit.datum.getScore());
// transfer all existing metadata to the redirect
newDatum.getMetaData().putAll(fit.datum.getMetaData());
scfilters.initialScore(redirUrl, newDatum);
if (reprUrl != null) {
newDatum.getMetaData().put(Nutch.WRITABLE_REPR_URL_KEY, new Text(reprUrl));
}
fit = FetchItem.create(redirUrl, newDatum, queueMode);
if (fit != null) {
FetchItemQueue fiq = ((FetchItemQueues) fetchQueues).getFetchItemQueue(fit.queueID);
fiq.addInProgressFetchItem(fit);
} else {
// stop redirecting
redirecting = false;
reporter.incrCounter("FetcherStatus", "FetchItem.notCreated.redirect", 1);
}
return fit;
}
private ParseStatus output(
Text key,
CrawlDatum datum,
Content content,
ProtocolStatus pstatus,
int status,
int outlinkDepth) {
datum.setStatus(status);
datum.setFetchTime(System.currentTimeMillis());
if (pstatus != null) datum.getMetaData().put(Nutch.WRITABLE_PROTO_STATUS_KEY, pstatus);
ParseResult parseResult = null;
if (content != null) {
Metadata metadata = content.getMetadata();
// store the guessed content type in the crawldatum
if (content.getContentType() != null)
datum
.getMetaData()
.put(new Text(Metadata.CONTENT_TYPE), new Text(content.getContentType()));
// add segment to metadata
metadata.set(Nutch.SEGMENT_NAME_KEY, segmentName);
// add score to content metadata so that ParseSegment can pick it up.
try {
scfilters.passScoreBeforeParsing(key, datum, content);
} catch (Exception e) {
if (LOG.isWarnEnabled()) {
LOG.warn("Couldn't pass score, url " + key + " (" + e + ")");
}
}
/*
* Note: Fetcher will only follow meta-redirects coming from the
* original URL.
*/
if (parsing && status == CrawlDatum.STATUS_FETCH_SUCCESS) {
if (!skipTruncated || (skipTruncated && !ParseSegment.isTruncated(content))) {
try {
parseResult = this.parseUtil.parse(content);
} catch (Exception e) {
LOG.warn("Error parsing: " + key + ": " + StringUtils.stringifyException(e));
}
}
if (parseResult == null) {
byte[] signature =
SignatureFactory.getSignature(conf)
.calculate(content, new ParseStatus().getEmptyParse(conf));
datum.setSignature(signature);
}
}
/*
* Store status code in content So we can read this value during parsing
* (as a separate job) and decide to parse or not.
*/
content.getMetadata().add(Nutch.FETCH_STATUS_KEY, Integer.toString(status));
}
try {
output.collect(key, new NutchWritable(datum));
if (content != null && storingContent) output.collect(key, new NutchWritable(content));
if (parseResult != null) {
for (Entry<Text, Parse> entry : parseResult) {
Text url = entry.getKey();
Parse parse = entry.getValue();
ParseStatus parseStatus = parse.getData().getStatus();
ParseData parseData = parse.getData();
if (!parseStatus.isSuccess()) {
LOG.warn("Error parsing: " + key + ": " + parseStatus);
parse = parseStatus.getEmptyParse(conf);
}
// Calculate page signature. For non-parsing fetchers this will
// be done in ParseSegment
byte[] signature = SignatureFactory.getSignature(conf).calculate(content, parse);
// Ensure segment name and score are in parseData metadata
parseData.getContentMeta().set(Nutch.SEGMENT_NAME_KEY, segmentName);
parseData.getContentMeta().set(Nutch.SIGNATURE_KEY, StringUtil.toHexString(signature));
// Pass fetch time to content meta
parseData.getContentMeta().set(Nutch.FETCH_TIME_KEY, Long.toString(datum.getFetchTime()));
if (url.equals(key)) datum.setSignature(signature);
try {
scfilters.passScoreAfterParsing(url, content, parse);
} catch (Exception e) {
if (LOG.isWarnEnabled()) {
LOG.warn("Couldn't pass score, url " + key + " (" + e + ")");
}
}
String origin = null;
// collect outlinks for subsequent db update
Outlink[] links = parseData.getOutlinks();
int outlinksToStore = Math.min(maxOutlinks, links.length);
if (ignoreExternalLinks || ignoreInternalLinks) {
URL originURL = new URL(url.toString());
// based on domain?
if ("bydomain".equalsIgnoreCase(ignoreExternalLinksMode)) {
origin = URLUtil.getDomainName(originURL).toLowerCase();
}
// use host
else {
origin = originURL.getHost().toLowerCase();
}
}
// used by fetchNode
if (fetchNode != null) {
fetchNode.setOutlinks(links);
fetchNode.setTitle(parseData.getTitle());
FetchNodeDb.getInstance().put(fetchNode.getUrl().toString(), fetchNode);
}
int validCount = 0;
// Process all outlinks, normalize, filter and deduplicate
List<Outlink> outlinkList = new ArrayList<Outlink>(outlinksToStore);
HashSet<String> outlinks = new HashSet<String>(outlinksToStore);
for (int i = 0; i < links.length && validCount < outlinksToStore; i++) {
String toUrl = links[i].getToUrl();
toUrl =
ParseOutputFormat.filterNormalize(
url.toString(),
toUrl,
origin,
ignoreInternalLinks,
ignoreExternalLinks,
ignoreExternalLinksMode,
urlFilters,
urlExemptionFilters,
normalizers);
if (toUrl == null) {
continue;
}
validCount++;
links[i].setUrl(toUrl);
outlinkList.add(links[i]);
outlinks.add(toUrl);
}
// Only process depth N outlinks
if (maxOutlinkDepth > 0 && outlinkDepth < maxOutlinkDepth) {
reporter.incrCounter("FetcherOutlinks", "outlinks_detected", outlinks.size());
// Counter to limit num outlinks to follow per page
int outlinkCounter = 0;
// Calculate variable number of outlinks by depth using the
// divisor (outlinks = Math.floor(divisor / depth * num.links))
int maxOutlinksByDepth =
(int)
Math.floor(outlinksDepthDivisor / (outlinkDepth + 1) * maxOutlinkDepthNumLinks);
String followUrl;
// Walk over the outlinks and add as new FetchItem to the queues
Iterator<String> iter = outlinks.iterator();
while (iter.hasNext() && outlinkCounter < maxOutlinkDepthNumLinks) {
followUrl = iter.next();
// Check whether we'll follow external outlinks
if (outlinksIgnoreExternal) {
if (!URLUtil.getHost(url.toString()).equals(URLUtil.getHost(followUrl))) {
continue;
}
}
reporter.incrCounter("FetcherOutlinks", "outlinks_following", 1);
// Create new FetchItem with depth incremented
FetchItem fit =
FetchItem.create(
new Text(followUrl),
new CrawlDatum(CrawlDatum.STATUS_LINKED, interval),
queueMode,
outlinkDepth + 1);
((FetchItemQueues) fetchQueues).addFetchItem(fit);
outlinkCounter++;
}
}
// Overwrite the outlinks in ParseData with the normalized and
// filtered set
parseData.setOutlinks(outlinkList.toArray(new Outlink[outlinkList.size()]));
output.collect(
url,
new NutchWritable(
new ParseImpl(new ParseText(parse.getText()), parseData, parse.isCanonical())));
}
}
} catch (IOException e) {
if (LOG.isErrorEnabled()) {
LOG.error("fetcher caught:" + e.toString());
}
}
// return parse status if it exits
if (parseResult != null && !parseResult.isEmpty()) {
Parse p = parseResult.get(content.getUrl());
if (p != null) {
reporter.incrCounter(
"ParserStatus", ParseStatus.majorCodes[p.getData().getStatus().getMajorCode()], 1);
return p.getData().getStatus();
}
}
return null;
}
@SuppressWarnings("fallthrough")
public void run() {
activeThreads.incrementAndGet(); // count threads
FetchItem fit = null;
try {
// checking for the server to be running and fetcher.parse to be true
if (parsing && NutchServer.getInstance().isRunning()) reportToNutchServer = true;
while (true) {
// creating FetchNode for storing in FetchNodeDb
if (reportToNutchServer) this.fetchNode = new FetchNode();
else this.fetchNode = null;
// check whether must be stopped
if (isHalted()) {
LOG.debug(getName() + " set to halted");
fit = null;
return;
}
fit = ((FetchItemQueues) fetchQueues).getFetchItem();
if (fit == null) {
if (feeder.isAlive() || ((FetchItemQueues) fetchQueues).getTotalSize() > 0) {
LOG.debug(getName() + " spin-waiting ...");
// spin-wait.
((AtomicInteger) spinWaiting).incrementAndGet();
try {
Thread.sleep(500);
} catch (Exception e) {
}
((AtomicInteger) spinWaiting).decrementAndGet();
continue;
} else {
// all done, finish this thread
LOG.info("Thread " + getName() + " has no more work available");
return;
}
}
lastRequestStart.set(System.currentTimeMillis());
Text reprUrlWritable = (Text) fit.datum.getMetaData().get(Nutch.WRITABLE_REPR_URL_KEY);
if (reprUrlWritable == null) {
setReprUrl(fit.url.toString());
} else {
setReprUrl(reprUrlWritable.toString());
}
try {
// fetch the page
redirecting = false;
redirectCount = 0;
do {
if (LOG.isInfoEnabled()) {
LOG.info(
"fetching "
+ fit.url
+ " (queue crawl delay="
+ ((FetchItemQueues) fetchQueues).getFetchItemQueue(fit.queueID).crawlDelay
+ "ms)");
}
if (LOG.isDebugEnabled()) {
LOG.debug("redirectCount=" + redirectCount);
}
redirecting = false;
Protocol protocol = this.protocolFactory.getProtocol(fit.url.toString());
BaseRobotRules rules = protocol.getRobotRules(fit.url, fit.datum);
if (!rules.isAllowed(fit.u.toString())) {
// unblock
((FetchItemQueues) fetchQueues).finishFetchItem(fit, true);
if (LOG.isDebugEnabled()) {
LOG.debug("Denied by robots.txt: " + fit.url);
}
output(
fit.url,
fit.datum,
null,
ProtocolStatus.STATUS_ROBOTS_DENIED,
CrawlDatum.STATUS_FETCH_GONE);
reporter.incrCounter("FetcherStatus", "robots_denied", 1);
continue;
}
if (rules.getCrawlDelay() > 0) {
if (rules.getCrawlDelay() > maxCrawlDelay && maxCrawlDelay >= 0) {
// unblock
((FetchItemQueues) fetchQueues).finishFetchItem(fit, true);
LOG.debug(
"Crawl-Delay for "
+ fit.url
+ " too long ("
+ rules.getCrawlDelay()
+ "), skipping");
output(
fit.url,
fit.datum,
null,
ProtocolStatus.STATUS_ROBOTS_DENIED,
CrawlDatum.STATUS_FETCH_GONE);
reporter.incrCounter("FetcherStatus", "robots_denied_maxcrawldelay", 1);
continue;
} else {
FetchItemQueue fiq = ((FetchItemQueues) fetchQueues).getFetchItemQueue(fit.queueID);
fiq.crawlDelay = rules.getCrawlDelay();
if (LOG.isDebugEnabled()) {
LOG.debug(
"Crawl delay for queue: "
+ fit.queueID
+ " is set to "
+ fiq.crawlDelay
+ " as per robots.txt. url: "
+ fit.url);
}
}
}
ProtocolOutput output = protocol.getProtocolOutput(fit.url, fit.datum);
ProtocolStatus status = output.getStatus();
Content content = output.getContent();
ParseStatus pstatus = null;
// unblock queue
((FetchItemQueues) fetchQueues).finishFetchItem(fit);
String urlString = fit.url.toString();
// used for FetchNode
if (fetchNode != null) {
fetchNode.setStatus(status.getCode());
fetchNode.setFetchTime(System.currentTimeMillis());
fetchNode.setUrl(fit.url);
}
reporter.incrCounter("FetcherStatus", status.getName(), 1);
switch (status.getCode()) {
case ProtocolStatus.WOULDBLOCK:
// retry ?
((FetchItemQueues) fetchQueues).addFetchItem(fit);
break;
case ProtocolStatus.SUCCESS: // got a page
pstatus =
output(
fit.url,
fit.datum,
content,
status,
CrawlDatum.STATUS_FETCH_SUCCESS,
fit.outlinkDepth);
updateStatus(content.getContent().length);
if (pstatus != null
&& pstatus.isSuccess()
&& pstatus.getMinorCode() == ParseStatus.SUCCESS_REDIRECT) {
String newUrl = pstatus.getMessage();
int refreshTime = Integer.valueOf(pstatus.getArgs()[1]);
Text redirUrl =
handleRedirect(
fit.url,
fit.datum,
urlString,
newUrl,
refreshTime < Fetcher.PERM_REFRESH_TIME,
Fetcher.CONTENT_REDIR);
if (redirUrl != null) {
fit = queueRedirect(redirUrl, fit);
}
}
break;
case ProtocolStatus.MOVED: // redirect
case ProtocolStatus.TEMP_MOVED:
int code;
boolean temp;
if (status.getCode() == ProtocolStatus.MOVED) {
code = CrawlDatum.STATUS_FETCH_REDIR_PERM;
temp = false;
} else {
code = CrawlDatum.STATUS_FETCH_REDIR_TEMP;
temp = true;
}
output(fit.url, fit.datum, content, status, code);
String newUrl = status.getMessage();
Text redirUrl =
handleRedirect(
fit.url, fit.datum, urlString, newUrl, temp, Fetcher.PROTOCOL_REDIR);
if (redirUrl != null) {
fit = queueRedirect(redirUrl, fit);
} else {
// stop redirecting
redirecting = false;
}
break;
case ProtocolStatus.EXCEPTION:
logError(fit.url, status.getMessage());
int killedURLs =
((FetchItemQueues) fetchQueues).checkExceptionThreshold(fit.getQueueID());
if (killedURLs != 0)
reporter.incrCounter(
"FetcherStatus", "AboveExceptionThresholdInQueue", killedURLs);
/* FALLTHROUGH */
case ProtocolStatus.RETRY: // retry
case ProtocolStatus.BLOCKED:
output(fit.url, fit.datum, null, status, CrawlDatum.STATUS_FETCH_RETRY);
break;
case ProtocolStatus.GONE: // gone
case ProtocolStatus.NOTFOUND:
case ProtocolStatus.ACCESS_DENIED:
case ProtocolStatus.ROBOTS_DENIED:
output(fit.url, fit.datum, null, status, CrawlDatum.STATUS_FETCH_GONE);
break;
case ProtocolStatus.NOTMODIFIED:
output(fit.url, fit.datum, null, status, CrawlDatum.STATUS_FETCH_NOTMODIFIED);
break;
default:
if (LOG.isWarnEnabled()) {
LOG.warn("Unknown ProtocolStatus: " + status.getCode());
}
output(fit.url, fit.datum, null, status, CrawlDatum.STATUS_FETCH_RETRY);
}
if (redirecting && redirectCount > maxRedirect) {
((FetchItemQueues) fetchQueues).finishFetchItem(fit);
if (LOG.isInfoEnabled()) {
LOG.info(" - redirect count exceeded " + fit.url);
}
output(
fit.url,
fit.datum,
null,
ProtocolStatus.STATUS_REDIR_EXCEEDED,
CrawlDatum.STATUS_FETCH_GONE);
}
} while (redirecting && (redirectCount <= maxRedirect));
} catch (Throwable t) { // unexpected exception
// unblock
((FetchItemQueues) fetchQueues).finishFetchItem(fit);
logError(fit.url, StringUtils.stringifyException(t));
output(
fit.url,
fit.datum,
null,
ProtocolStatus.STATUS_FAILED,
CrawlDatum.STATUS_FETCH_RETRY);
}
}
} catch (Throwable e) {
if (LOG.isErrorEnabled()) {
LOG.error("fetcher caught:" + e.toString());
}
} finally {
if (fit != null) ((FetchItemQueues) fetchQueues).finishFetchItem(fit);
activeThreads.decrementAndGet(); // count threads
LOG.info("-finishing thread " + getName() + ", activeThreads=" + activeThreads);
}
}
