Master-Slave replica: new caches will be warmed&prepopulated _before_ making new IndexReader available for _new_ requests and _before_ discarding old one - it means that theoretical sizing for FieldCache (which is defined by number of docs in an index and cardinality of a field) should be doubled... of course we need to play with GC options too for performance tuning (mostly)
> > I read pretty much all posts on this thread (before and after this one). > Looks > > like the main suggestion from you and others is to keep max heap size > (-Xmx) > > as small as possible (as long as you don't see OOM exception). > > > I suggested absolute opposite; please note also that "as small as possible" > does not have any meaning in multiuser environment of Tomcat. It depends on > query types (10 documents per request? OR, may be 10000???) AND it depends > on average server loading (one concurrent request? Or, may be 200 threads > trying to deal with 2000 concurrent requests?) AND it depends on whether it > is Master (used for updates - parses tons of docs in a single file???) - and > it depends on unpredictable memory fragmentation - it all depends on use > case too(!!!), additionally to schema / index size. > > > Please note also, such staff depends on JVM vendor too: what if it > precompiles everything into CPU native code (including memory dealloc after > each call)? Some do! > > -Fuad > http://www.linkedin.com/in/liferay > > > ...but 'core' constantly disagrees with me :) > > >
