nutch-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Susam Pal (JIRA)" <j...@apache.org>
Subject [jira] Commented: (NUTCH-601) Recrawling on existing crawl directory using force option
Date Tue, 05 Feb 2008 18:50:08 GMT

    [ https://issues.apache.org/jira/browse/NUTCH-601?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12565848#action_12565848
] 

Susam Pal commented on NUTCH-601:
---------------------------------

The 'if (newIndex != index)' condition is just a check whether this is a new crawl directory
being constructed, or it is a recrawl on a previous crawl directory.

If it is a new crawl directory being constructed, a few lines above this check, there is another
'if (!fs.exists(index))' condition which will set the newIndex = index = '/index'. So, if
both newIndex and index are same, we know that it is a new crawl directory and we need not
delete old 'index' because it would not be present.

If it is a recrawl over a previous crawl directory, newIndex = '/new_index' and index = '/index'.
Since they are different, it indicates that this is a recrawl and thus after '/new_index'
is created, it'll quickly replace the old '/index' with the '/new_index'.

This seems fine to me.

If you want to avoid the possibility of having new segments with old index if something bad
happens, then I should delete both 'index' and 'indexes' even before the generate call. But
I didn't want to delete old 'index' so early. I was trying to minimize the time for which
'index' directory is unavailable. This would be helpful in case someone is running a recrawl
on the same 'crawl' directory which the web-gui is using to serve search results.

Please let me know what you feel about this.

> Recrawling on existing crawl directory using force option
> ---------------------------------------------------------
>
>                 Key: NUTCH-601
>                 URL: https://issues.apache.org/jira/browse/NUTCH-601
>             Project: Nutch
>          Issue Type: Improvement
>    Affects Versions: 1.0.0
>            Reporter: Susam Pal
>            Priority: Minor
>         Attachments: NUTCH-601v0.1.patch, NUTCH-601v0.2.patch
>
>
> Added a '-force' option to the 'bin/nutch crawl' command line. With this option, one
can crawl and recrawl in the following manner:
> {code}
> bin/nutch crawl urls -dir crawl -depth 2 -topN 10 -threads 5
> bin/nutch crawl urls -dir crawl -depth 2 -topN 10 -threads 5 -force
> {code}
> This option can be used for the first crawl too:
> {code}
> bin/nutch crawl urls -dir crawl -depth 2 -topN 10 -threads 5 -force
> bin/nutch crawl urls -dir crawl -depth 2 -topN 10 -threads 5 -force
> {code}
> If one tries to crawl without the -force option when the crawl directory already exists,
he/she finds a small warning along with the error message:
> {code}
> # bin/nutch crawl urls -dir crawl -depth 2 -topN 10 -threads 5
> Exception in thread "main" java.lang.RuntimeException: crawl already
> exists. Add -force option to recrawl.
>        at org.apache.nutch.crawl.Crawl.main(Crawl.java:89)
> {code}

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message