On 3/21/11 7:54 AM, Luca Morandini wrote: >> I have been running some stress tests with jmeter just last week and on that >> bases it looks like Apache can harm GWC service a bit under heavy load . At >> least in our environment it started to introduce some slow periods for >> generally fast service with more than 20 concurrent users. System behaved >> like >> sending some 2000 tiles fast at rate of about 200 tiles per second, then >> nearly >> full stop for a few seconds, and after taking a breath it was fast again. >> Without Apache proxy the systems was stable. > Duh ! > > This is something odd, very odd: the overhead involved in using mod_proxy is > negligible... are you sure there weren't some other factors at work ? > > Please, keep us posted on this. > > Regards, > > Luca Morandini > http://www.lucamorandini.it > Not sure about the intermittent slowdowns, but in general it is not that simple. mod_proxy doubles the number of threads*, and the number of TCP/IP connections needed. Last time I checked GWC throughput peaked somewhere between 2000 or 4000 simultaneous threads (against a realistic set of clients, a mixture of slow and fast, not gigabit ethernet clients).
At that point the additional TCP/IP connections + threads in Apache are not neglible anymore. -Arne * The default MPM for Apache is prefork, which means one Apache process per request, is completely hopeless for this purpose ------------------------------------------------------------------------------ Colocation vs. Managed Hosting A question and answer guide to determining the best fit for your organization - today and in the future. http://p.sf.net/sfu/internap-sfd2d _______________________________________________ Geoserver-users mailing list Geoserver-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/geoserver-users
