Hello, I also noticed the same thing by updating jena-tdb only. I switched from version 0.9.0-incubating to snapshots on 6 June and I noticed around ~50% decrease on one of our benchmark which is read/write intensive.
Kind Regards, Laurent On Wed, Jun 13, 2012 at 4:33 PM, Simon Helsen <[email protected]> wrote: > before you ask, of course, we are looking into whether this is something > on our end. We only made very few changes, but we should be able to > isolate this. I'll report on that once I know for sure. My question was > more whether anyone knew of any changes in tx that could affect concurrent > performance negatively since May 15 > > thanks > > Simon > > > > > > From: > Simon Helsen/Toronto/IBM@IBMCA > To: > [email protected] > Date: > 06/13/2012 10:09 AM > Subject: > concurrency and slower results > > > > hi everyone, Andy especially, > > it looks like some of the changes to TDB since May 15 have negatively > affected the concurrent behavior of Tx. To clarify, we are doing some > serious internal performance testing on a product which is based on > Jena/TDB. We initially did these runs to compare Tx (2.7.1 snapshot of May > > 15) with our old TDB implementation (which used a conservative locking > model). The results were good, especially with long-running/expensive > index update operations. > > Now, I had asked the performance team to rerun their tests with a new > build of the product based on the release candidate (of last weekend) and > they are reporting a concerning degradation. Compared to the May 15 TDB, > they are reporting 12-15% decrease in query performance when doing a > "light update load" and about 40% query and 40% update performance > degradation when doing a "heave update load". > > That is quite a serious regression. The question is what changed since May > > 15 that could have such a bad effect on performance. The tests included > only 25 concurrent users on about 15 million triples. Yet, I wonder if > some of the recent lock changes (see JENA-252) are responsible > > thanks > > Simon > > >
