On Tue, Sep 8, 2009 at 5:46 PM, Andrea Aime<[email protected]> wrote: > Hi, > yesterday I've got confirmation there are some big bad locks > in the Java rendering subsystem that do prevent a system > to use a multicore architecture effectively: > http://jira.codehaus.org/browse/GEOS-3423 > > In fact I have been observing CPU utization well below > 100% in various mulithreaded benchmarks where the > number of client threads far exceeded the number > of available CPUs... those locks that explains it, > and I had confirmation using Yourkit. > > So today I set up to try and have the renderer do something > in the time it cannot render in parallel: try to prefetch > data from the store while rendering is happening. > > I've then run again some benchmarks, with mixed results. > StreamingRenderer + shapefile datastore gets quite a benefit > and becomes in some cases 30% faster than the shapefile > renderer itself, in some others 10% slower (but the > datastore is not optimized to work with the streaming > renderer, so I'm confident it can get faster in 100% of > the cases with some more work). > > StreamingRendere + postgis datastore is around +10/-10 > depending on the workload. > > I would have thought to always get better performance > on lighter loads, considering the second core of my > machine could have helped by doing the parallel data > fetching, but that did not always happen (it happened > big time only in one tests, where the speed at light > load almost doubled). > > Maybe there is something wrong with the way I've > coded up the prefecthin iterator? Someone more familiar > with the concurrent java utilitis might be able to tell. > > More in general, how do people feel about this? > Good for a configuration knob in the StreamingRenderer? > Or just the new default? >
My 2c, I'd rather make it a configuration flag. Simone > Cheers > Andrea > > -- > Andrea Aime > OpenGeo - http://opengeo.org > Expert service straight from the developers. > > ------------------------------------------------------------------------------ > Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day > trial. Simplify your report design, integration and deployment - and focus > on > what you do best, core application coding. Discover what's new with > Crystal Reports now. http://p.sf.net/sfu/bobj-july > _______________________________________________ > Geotools-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/geotools-devel > > ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Geotools-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-devel
