Hmm, this sounds hairy :) Are you sure NRTCachingDir won't work for you?
Mike McCandless http://blog.mikemccandless.com On Tue, Jun 14, 2011 at 5:58 AM, Ganesh <emailg...@yahoo.co.in> wrote: > Is it a bad idea to keep multiple shards in a single system? > > Regards > Ganesh > > ----- Original Message ----- > From: "Toke Eskildsen" <t...@statsbiblioteket.dk> > To: <java-user@lucene.apache.org> > Sent: Tuesday, June 14, 2011 12:58 PM > Subject: Re: Index size and performance degradation > > >> On Sun, 2011-06-12 at 10:10 +0200, Itamar Syn-Hershko wrote: >>> The whole point of my question was to find out if and how to make >>> balancing on the SAME machine. Apparently thats not going to help and at >>> a certain point we will just have to prompt the user to buy more hardware... >> >> It really depends on your scenario. If you have few concurrent requests >> and are looking to minimize latency, sharding might help; assuming you >> have fast IO and multiple cores. You basically want to saturate all >> available resources for all requests. >> >> On the other hand, if throughput is the issue, sharding on a single >> machine is counter-productive due to increased duplication and merging. >> >>> Out of curiosity, isn't there anything that we can do to avoid that? for >>> instance using memory-mapped files for the indexes? anything that would >>> help us overcome OS limitations of that sort... >> >> One standard advice for speeding up searches is using SSD's. Our >> (admittedly old) experiments puts SSD-performance near RAM. With the >> prices we have now, SSD's seems like an obvious choice for most setups. >> >> We tried a few performance tests at different index sizes and for us, >> index size vs. performance looked like the power law: Heavy performance >> degradation in the beginning, less later. It makes sense when we look at >> caching and it means that if you do not require stellar performance, you >> can have very large indexes on few machines (cue Hathi Trust). >> >> - Toke Eskildsen >> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org >> For additional commands, e-mail: java-user-h...@lucene.apache.org >> > > --------------------------------------------------------------------- > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > For additional commands, e-mail: java-user-h...@lucene.apache.org > > --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
