On 27 May 2012 23:02, Oleg Kalnichevski <[email protected]> wrote: > On Sun, 2012-05-27 at 23:08 +0200, Philippe Mouawad wrote: >> Hello Oleg,milamber, >> Thanks for your investigations. >> >> Oleg, Regarding connectionmanager, do you think it's better to use one >> connmgr for all vus ? >> Today we use one per VU but we reuse httpclient instance when downloading >> embedded résources in parallèl mode. >> What would be the compromise ? >> >> Thanks >> Regards >> Philippe >> > > Hi Philippe > > It really depends on what you define as 'better' and what your > objectives are. If your goal is to emulate load generated by 20 browser > instances as realistic as possible you should be using a separate > connection manager per virtual user. (In this case, though, you should > be using a pooling connection configured to allow up to 2 simultaneous > connections to the same host instead of a basic connection manager with > a single connection).
Why would 2 connections be needed? > If your goal is to generate as much load as > possible using 20 virtual users you should be using a pooling connection > manager configured to allow up to 20 connections to the same host shared > by all virtual users. If 2 connections are needed for the first case, wouldn't we need some spare connections in this case too? > You should also take into account that Java standard HttpUrlConnection > is not well suited for the former scenario as it always uses one global > connection pool for all its instances. This is likely to be the reason > why the HttpUrlConnection based sampler tends to yield the highest > request per second in the performance tests. JMeter has historically tried to ensure each VU behaves completely independently. I don't think we should change that by default. However, it might be worth considering optionally using a shared connection pool. <snip/>
