FAQ
For one of our projects - we were planning to have the system of
multiple individual Lucene readers (just read-only instances and no
writes whatsoever ) in different physical machines having their
IndexReader-s warmed up from the same directory for the indices and
working on the same.

I was reading about locks (implemented as files) that Lucene uses
internally. I am just curious if using multiple readers would be a
feasible option here, all sharing the same index directory (across NFS /
similar network mounted storage ) in terms of locking etc.

Would there be a performance hit ( ignoring the NFS related performance
of course) that would hinder multiple readers to serve query search
simultaneously from the same set of index files.

---------------------------------------------------------------------
To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
For additional commands, e-mail: java-user-help@lucene.apache.org

Search Discussions

  • Tomer Gabel at Dec 23, 2008 at 11:07 am
    Ultimately it depends on your specific usage patterns. Generally speaking, if
    you have IndexReaders (and do not use their delete functionality) you don't
    need locking at all; you can use a no-op lock factory, in which case you'll
    pretty much only be constrained by your storage subsystem.


    Kay Kay-3 wrote:
    For one of our projects - we were planning to have the system of
    multiple individual Lucene readers (just read-only instances and no
    writes whatsoever ) in different physical machines having their
    IndexReader-s warmed up from the same directory for the indices and
    working on the same.

    I was reading about locks (implemented as files) that Lucene uses
    internally. I am just curious if using multiple readers would be a
    feasible option here, all sharing the same index directory (across NFS /
    similar network mounted storage ) in terms of locking etc.

    Would there be a performance hit ( ignoring the NFS related performance
    of course) that would hinder multiple readers to serve query search
    simultaneously from the same set of index files.

    ---------------------------------------------------------------------
    To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
    For additional commands, e-mail: java-user-help@lucene.apache.org


    -----
    --

    http://www.tomergabel.com Tomer Gabel


    --
    View this message in context: http://www.nabble.com/Multiple-IndexReaders-from-the-same-Index-Directory---issues-with-Locks---performance-tp21136262p21142273.html
    Sent from the Lucene - Java Users mailing list archive at Nabble.com.


    ---------------------------------------------------------------------
    To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
    For additional commands, e-mail: java-user-help@lucene.apache.org
  • Michael McCandless at Dec 23, 2008 at 2:04 pm
    Locking is completely unused from IndexReader unless you do deletes or
    change norms, so sharing a remote mounted index is just fine (except
    for performance concerns).

    If you're using 2.4, you should open your readers with readOnly=true.

    Mike

    Tomer Gabel wrote:
    Ultimately it depends on your specific usage patterns. Generally
    speaking, if
    you have IndexReaders (and do not use their delete functionality)
    you don't
    need locking at all; you can use a no-op lock factory, in which case
    you'll
    pretty much only be constrained by your storage subsystem.


    Kay Kay-3 wrote:
    For one of our projects - we were planning to have the system of
    multiple individual Lucene readers (just read-only instances and no
    writes whatsoever ) in different physical machines having their
    IndexReader-s warmed up from the same directory for the indices and
    working on the same.

    I was reading about locks (implemented as files) that Lucene uses
    internally. I am just curious if using multiple readers would be a
    feasible option here, all sharing the same index directory (across
    NFS /
    similar network mounted storage ) in terms of locking etc.

    Would there be a performance hit ( ignoring the NFS related
    performance
    of course) that would hinder multiple readers to serve query search
    simultaneously from the same set of index files.

    ---------------------------------------------------------------------
    To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
    For additional commands, e-mail: java-user-help@lucene.apache.org


    -----
    --

    http://www.tomergabel.com Tomer Gabel


    --
    View this message in context: http://www.nabble.com/Multiple-IndexReaders-from-the-same-Index-Directory---issues-with-Locks---performance-tp21136262p21142273.html
    Sent from the Lucene - Java Users mailing list archive at Nabble.com.


    ---------------------------------------------------------------------
    To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
    For additional commands, e-mail: java-user-help@lucene.apache.org

    ---------------------------------------------------------------------
    To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
    For additional commands, e-mail: java-user-help@lucene.apache.org

Related Discussions

Discussion Navigation
viewthread | post
Discussion Overview
groupjava-user @
categorieslucene
postedDec 22, '08 at 10:35p
activeDec 23, '08 at 2:04p
posts3
users3
websitelucene.apache.org

People

Translate

site design / logo © 2022 Grokbase