Thanks for the response, Mike. In our solution, the entire index is memory mapped.
On Thu, May 20, 2010 at 2:05 PM, Mike Klaas <[email protected]> wrote: > Solr and Lucene rely on the OS disk cache for speedy queries. If they > are left idle for hours while the disk is used for other purposes, the > OS will page out some of the lucene index (and it will have to be > paged back in the next time a query is received). > > The best way to prevent this from occurring is to set up a periodic > automatic query using crontab that keeps the system warm. > > cheers, > -Mike > > On Wed, May 19, 2010 at 2:19 PM, ST ST <[email protected]> wrote: > > Folks, > > > > We have a problem in our environment where after a system is idle the > query > > time goes up from a few 100ms to 4+ seconds after 9 hours of idle time on > > the system. > > > > System Details: > > - Solr 1.4 with Lucene 2.9 > > - 10 Million Index. > > - Use MMAP for mapping the index files in memory > > > > Test Details: > > - 8 hour performance run with ingestion (@ 8 docs/sec) , query rate - 3 > > Queries per sec. > > - Commit is per hour. > > > > Issue: > > - After 9 hours of idle time (ie no queries, no ingestion ) every query > > takes 4+ seconds, subsequent queries are fast. > > > > I have a few specific questions: > > A. Does Lucene/Solr have internal caches which may be flushed out of > memory > > when the system is idle ? > > B. What operations are done on a per term basis (example: build doc lists > ) > > for first time queries. > > C. Any pointers to what else may be an issue here. > > > > Really appreciate any help you can provide. > > > > ST > > > > > > > > > > > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > >
