Hi Fuad, On Wed, Sep 23, 2009 at 11:37 AM, Fuad Efendi <f...@efendi.ca> wrote:
> > 8 queries against 1 Tomcat average 600ms per query, while 8 queries > against > > 8 Tomcats average 190ms per query (on a dedicated 8 CPU server w 32G > RAM). > > I don't see how to interpret these numbers except that Tomcat is not > > multithreading as well as it should :) > > Hi Michael, I think it is very natural; 8 single processes not sharing > anything are faster than 8 threads sharing something. > 8 threads sharing something may have *some* overhead versus 8 processes, but as you say, 410ms overhead points to a different problem. However, 600ms is too high. > > >My index is on a > >ramfs which I've shown makes the QR and doc caches unnecessary; > > However, SOLR is faster than pure Lucene, try SOLR caches! > I have. In a separate test, I verified that the caches that save disk I/O (QR and doc) make no difference to query time, because my index is on a ramfs. The caches that save CPU cycles (filter and fieldvalue, because I'm doing heavy faceting) DO help and I do have them turned on. Michael
