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 <samarz...@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 > --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
