[ http://issues.apache.org/jira/browse/NUTCH-233?page=comments#action_12423438 ] Stefan Groschupf commented on NUTCH-233: ----------------------------------------
I think this should be fixed in .8 too, since everybody that does real whole web crawl with over a 100 Mio pages will run into this problem. The problems are for example from spam bot generated urls. > wrong regular expression hang reduce process for ever > ----------------------------------------------------- > > Key: NUTCH-233 > URL: http://issues.apache.org/jira/browse/NUTCH-233 > Project: Nutch > Issue Type: Bug > Affects Versions: 0.8-dev > Reporter: Stefan Groschupf > Priority: Blocker > Fix For: 0.9-dev > > > Looks like that the expression ".*(/.+?)/.*?\1/.*?\1/" in regex-urlfilter.txt > wasn't compatible with java.util.regex that is actually used in the regex url > filter. > May be it was missed to change it when the regular expression packages was > changed. > The problem was that until reducing a fetch map output the reducer hangs > forever since the outputformat was applying the urlfilter a url that causes > the hang. > 060315 230823 task_r_3n4zga at > java.lang.Character.codePointAt(Character.java:2335) > 060315 230823 task_r_3n4zga at > java.util.regex.Pattern$Dot.match(Pattern.java:4092) > 060315 230823 task_r_3n4zga at > java.util.regex.Pattern$Curly.match1(Pattern.java: > I changed the regular expression to ".*(/[^/]+)/[^/]+\1/[^/]+\1/" and now the > fetch job works. (thanks to Grant and Chris B. helping to find the new regex) > However may people can review it and can suggest improvements, since the old > regex would match : > "abcd/foo/bar/foo/bar/foo/" and so will the new one match it also. But the > old regex would also match : > "abcd/foo/bar/xyz/foo/bar/foo/" which the new regex will not match. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira
