I was going to inject a single simple page that redirects to another
page with zero links on the pages themselves. And fetch/update this
against a clean crawldb. Then see what the dump output of the crawldb
is after being updated.
If it works the way I think it does then there should be multiple urls
into the crawldb. If you want to try that and let me know the output it
would be great. I am trying to finish up getting patches committed for
the 1.0 release so am a little busy.
Dennis
John Mendenhall wrote:
Dennis,
I will need to look deeper but I think there is a subtle logic bug in
Fetcher.
Redirect statuses, both temp and perm get output by the fetchers, even
when redirecting immediately, so if you have multiple redirects you
would have multiple outputs in the crawl_fetch output from segments.
The outputs are by url, but the urls change with redirects.
When updating to crawldb the latest (in terms of time) update is used.
But that is per url and I don't think it updates the redirected urls.
Meaning the updated crawldb would contain the successfully fetched urls
and the redirected intermediate urls. At least that is what I think is
happening.
The final number indexed should be the successfully fetched urls, which
would be db_fetched.
Dennis
Anything I can do to help debug this?
JohnM
John Mendenhall wrote:
On Thu, 04 Dec 2008, Dennis Kubes wrote:
Forget my last email. I went back and read your original email. What
type of webpages are you trying to fetch? This doesn't seem like a
configuration issue to me.
Most of this particular url set are redirects.
The pages are dynamic pages, all from a single
website, served by hundreds of web servers,
requested through a local proxy server (local to
nutch server).
I believe the urlfilter is set correctly.
The logs are stating the pages are getting
fetched now. I have debug set for fetcher
and generator. I am not seeing messages
of the urls being skipped. Perhaps I need
to debug elsewhere to find out why we are
not getting the urls fetched and indexed.
I did increase topN to 1000000. We got quite
a bit more, but still not all of the pages.
The current status breakdown after an additional
cycle is:
status 1 (db_unfetched): 19265
status 2 (db_fetched): 159912
status 3 (db_gone): 2
status 4 (db_redir_temp): 299024
status 5 (db_redir_perm): 230154
status 6 (db_notmodified): 159418
Searchable results is now about 287k.
Total urls in crawldb is listed as 867775.
Thanks for your assistance.
JohnM
Dennis Kubes wrote:
Hi John,
If the http.redirect.max config variable in nutch-*.xml is set to 0 then
any redirect is queued to be fetched during the next fetching round
similar to new urls we parse off of a webpage. Try setting it to 3 and
your redirects should go down.
Dennis
John Mendenhall wrote:
We are using nutch version nutch-2008-07-22_04-01-29.
We have a crawldb with over 500k urls.
The status breakdown was as follows:
status 1 (db_unfetched): 19261
status 2 (db_fetched): 71628
status 4 (db_redir_temp): 274899
status 5 (db_redir_perm): 148220
status 6 (db_notmodified): 822
We had set the http.redirect.max property to 7, in
the nutch-site.xml file. We are currently using
bin/nutch fetch.
We have set logging level to debug for the Fetcher. We see the
fetching log entries. We see the protocol
redirect to log entries. However, after a complete
cycle of fetch/update/merge/index, etc, all the numbers
above stayed the same.
We originally fetched with the obsolete setting
of db.default.fetch.interval set to 365 days.
We now have db.fetch.interval.default set to 35 days.
We run the generate cycle with -add-days 370 to
refetch all those urls. This does not appear to be
working.
We found db.update.additions.allowed, set to false
>from a previous run type. We tried setting it to
true. Now, after several more cycles, our status
breakdown is now:
status 1 (db_unfetched): 19270
status 2 (db_fetched): 100230
status 3 (db_gone): 1
status 4 (db_redir_temp): 278559
status 5 (db_redir_perm): 168816
status 6 (db_notmodified): 64366
The number of fetched and searchable pages has gone
>from about 72000 to about 140k (per the search
interface).
Our question is, what can we do to get these redirected
pages indexed? Do we need to increase add-days?
Do we need to increase our topN (currently using
100k)? Or, do we just need to start over?
After a couple more days, our status breakdown is as
follows:
status 1 (db_unfetched): 19261
status 2 (db_fetched): 100198
status 3 (db_gone): 2
status 4 (db_redir_temp): 279591
status 5 (db_redir_perm): 171076
status 6 (db_notmodified): 80227
Fetched has gone down, with not modified going up.
Search results through the search interface has gone up
to about 148500 results.
There must be some configuration variable we have not
set properly. We use topN of 100000. We run it through
the cycle about 8 times per day, with only small incremental
progress each round. Should topN be higher?
Or, do we need to rebuild the entire crawl database?
Please let me know if there is any information I need to
provide.
Thanks in advance for any assistance provided.
JohnM
