nutch use the concepts of segments and yes you are able to update
part of the index by just delete older older segments and generate /
fetch new segments.
Stefan
Am 08.11.2005 um 18:38 schrieb Jack Tang:
Hi
I read GFS document and NFS document on the wiki. One interesting
question here: does NFS support updating index on the fly?
As you known, google updats its index via google dance. It is said
that replicator in GFS placed three copies of chunks in different
datanode. During index updating, the two chunks will be locked,
updated first, finally the remain is updated. I do not know it is true
or not. However, from NFS
document(http://wiki.apache.org/nutch/NutchDistributedFileSystem) I
learned:
1. Files can only be written once. After the first write, they
become read-only. (Although they can be deleted.)
2. Files are stream-oriented; you can only append bytes, and you
can only read/seek forward.
3. There are no user permissions or quotas, although these could be
added fairly easily.
There are no "write" and "lock" i/o semantics, so we cannot update
index in dynamic, right?
Regards
/Jack
P.S.
what is the google dance: http://www.metamend.com/google-dance.html
Google Dance - The Index Update of the Google Search Engine :
http://dance.efactory.de/
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