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From Samarendra Pratap <samarz...@gmail.com>
Subject Re: Reopening a Searcher for each request
Date Thu, 22 Apr 2010 11:29:35 GMT
Thanks Mike.
That solved a query which was itching my mind for a long time.

On Thu, Apr 22, 2010 at 4:41 PM, Michael McCandless <
lucene@mikemccandless.com> wrote:

> It's the IndexReader that's costly to open/warm, so ideally it should
> be opened once and shared.
>
> The Searchers do very little on construction so re-creating per query
> should be OK.
>
> Mike
>
> On Thu, Apr 22, 2010 at 6:38 AM, Samarendra Pratap <samarzone@gmail.com>
> wrote:
> > Greetings to all.
> >  I have read at so many places that we should not open a Searcher for
> each
> > request for the sake of performance, but I have always been wondering
> > whether it is actually Searcher or Reader?
> >
> >  I have a group of index amounting to 23G which actually contains of
> > different index directories. The structure is something like following
> >
> > Main directory
> > |
> > |_________ country1
> > |                     |___ country1-time1 (actual index)
> > |                     |___ country1-time2 (actual index)
> > |                     |___ country1-time3 (actual index)
> > |
> > |_________ country2
> >                     |___ country2-time1 (actual index)
> >                     |___ country2-time2 (actual index)
> >                     |___ country2-time3 (actual index)
> >
> >  When application starts I open IndexReaders on all of actual index
> > directories (country1-time1, country1-tim2, .... country2-time3) and keep
> > them in a pool.
> >
> >  At the time of search, IndexSearchers are created by selecting the
> > appropriate IndexReaders from the pool. These IndexSearchers in turn are
> > used to create a ParallelMultiSearcher. Constructors of IndexSearcher and
> > ParallelMultiSearcher are run for every request.
> >
> >  Now I believe that creating a pool of ParallelMultiSearcher itself is a
> > good idea but* I wanted to know if reopening **IndexSearchers** will
> really
> > degrade performance irrespective of **IndexReaders** being opened once*.
> >
> > In my performance tests (which may not be very comprehensive) I didn't
> find
> > any noticeable difference.
> >
> > Please throw some light.
> >
> >
> > --
> > Regards,
> > Samar
> >
>
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>


-- 
Regards,
Samar

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