[
https://issues.apache.org/jira/browse/NUTCH-656?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13777426#comment-13777426
]
Julien Nioche commented on NUTCH-656:
-------------------------------------
Hi Markus
Good points. Re-scoring plugin we could make the code more robust by giving a
default score if none can be found. As for not_modified not being in the index,
then nothing wrong will happen to it when we ask the indexing backend to delete
it, right? I assume your point about the fetch time intervals is that it does
not differentiate between when a page was last fetched and when it will be
fetched. Is that correct?
Doesn't the current solr-dedup have the same shortcomings anyway? e.g. tstamp
generated by index-basic - what happens if it is not activated?
Thanks a lot
Julien
> DeleteDuplicates based on crawlDB only
> ---------------------------------------
>
> Key: NUTCH-656
> URL: https://issues.apache.org/jira/browse/NUTCH-656
> Project: Nutch
> Issue Type: Wish
> Components: indexer
> Reporter: Julien Nioche
> Assignee: Julien Nioche
> Attachments: NUTCH-656.patch
>
>
> The existing dedup functionality relies on Lucene indices and can't be used
> when the indexing is delegated to SOLR.
> I was wondering whether we could use the information from the crawlDB instead
> to detect URLs to delete then do the deletions in an indexer-neutral way. As
> far as I understand the content of the crawlDB contains all the elements we
> need for dedup, namely :
> * URL
> * signature
> * fetch time
> * score
> In map-reduce terms we would have two different jobs :
> * read crawlDB and compare on URLs : keep only most recent element - oldest
> are stored in a file and will be deleted later
> * read crawlDB and have a map function generating signatures as keys and URL
> + fetch time +score as value
> * reduce function would depend on which parameter is set (i.e. use signature
> or score) and would output as list of URLs to delete
> This assumes that we can then use the URLs to identify documents in the
> indices.
> Any thoughts on this? Am I missing something?
> Julien
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
