We are deploying or web application on Jboss EAP 5.2. The web application receives a webservice call to process requests.
The two instances of production profile is deployed on two different boxes and request is distributed using a http server. The two boxes are 2 core machines.
We have tried to tune the jboss profile as described on various results on forum - thread group, memory settings, and other JAVA_OPT parameters.
We get very consistent results and bechmarked results while running the tests with 16 simultaneous users.
If we increase the number of users to 20 (10 for each box) - we get inconsistent results for multiple runs. We response time just doubles up and there is no consistent pattern on the same.
I believe if multiple users are not supported by application server or box level settings - we would get bad performance but atleast consistent results.
Is there any recommendations on the performance settings to get the best results when multiple users are invoking the webservice simultaneously?