Hi Brian,

Well, it took me a while to figure it out too :-).

The number of parts actually is the number of reduce tasks defined in
hadoop-site.xml. If you are working with only one machine this value should
be one and when you run different jobs you will notice that the result is
saved in part-00000 if you had two machines and you also changed the number
of reduce to two you would get part-0000 and part-0001 and so on.
To emphasize: If you ran the following command and you have two machines in
your cluster:
Bin/nutch index indexes crawldb linkdb segments/2007....
Than you will end up with the folder indexes which contains two folders
part-00000 and part-00001 and each of these folders contains a Lucene index.
You could actually import each of those folders and open it with Luke.


Now to merge:
The merge program doesn't care what the name of the folder is. It cares it
should be in a certain structure.

So if we assume you have a folder named indexes, the program wants that each
folder inside indexes (represents a previous run of index) should have a
Lucene index in it (it looks for a folder name segments).


What I do (I run the whole process of generate-merge in a loop) is I create
the index in the DFS root with a name like the segments (2007...) and than I
transfer the parts folders to the indexes folder (I rename it from part...
to date-00001 and so forth.
Than you could call merge and it shall merge all indexes.

HTH,

Gal








-----Original Message-----
From: Brian Whitman [mailto:[EMAIL PROTECTED] 
Sent: Thursday, February 15, 2007 11:13 PM
To: [email protected]
Subject: crawl indexes and part-00000

I am looking for a simple explanation on what the "part-00000"  
directory in my craw/index folders are, and when they are created and  
when they are not.

I am having a bit of a trouble merging multiple nutch-created indexes  
using bin/nutch merge -- the merge tools seems to always expect the  
index directory to only have a "part-00000" folder in it with the  
actual lucene indexes below. For some reason, in my crawls I end up  
with some index dirs with the part-00000 and some index dirs without  
it. And so I get "IndexMerger: java.io.IOException: crawl/index/ 
_0.fnm not a directory"

How could this happen? Do all nutch index generation tools generate  
this part-00000 folder? Did something mess up up the chain? Will  
there ever be a part-00001? :)







-------------------------------------------------------------------------
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys-and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
_______________________________________________
Nutch-general mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/nutch-general

Reply via email to