Dual CPU, AEM only using single CPU

[Sutty100]

My local dev environment is an older Mac Pro one of the Dual CPU variants running OS X (10.11). I was doing some basic load testing of a servlet using Jmeter I was writing on AEM and noticed that it seemed to be only placing load on one of the two CPUs (Note physical CPU's not cores). Why is this the case I'd expect AEM to happily make use of all CPU's. Is this a licensing issues that limits AEM to a single CPU for a dev instance or perhaps its simply an issue with OS X and how it distributes load across dual cpu macs (I haven't tried this on linux or windows on this mac yet)? Not a big issue just more curious and I also wanted to see what impact it had on my response times!

[kautuk_sahni · Accepted solution]

hi 

Your JVM and/or the host OS decide how many 'native' threads to use, and how those threads are mapped to physical processors not the AEM, So its more of OS decision then AEM. You do have some options for tuning. For example, I found [1] talks about other things that can slow down a multi-threaded application, program isn't scaling with number of processors etc.

Good Reference Read:- http://stackoverflow.com/questions/1223072/forcing-multiple-threads-to-use-multiple-cpus-when-they-a...

                                   http://stackoverflow.com/questions/4436422/how-does-java-makes-use-of-multiple-cores

[1] http://www.oracle.com/technetwork/java/hotspotfaq-138619.html#perf%5Fscaling

I hope this will help you.

Thanks and Regards

Kautuk Sahni