Threads configuration based on no. of CPU-cores

Question

Scenario : I have a sample application and I have 3 different system configuration -

- 2 core processor, 2 GB RAM, 60 GB HHD,
- 4 core processor, 4 GB RAM, 8         


        

Answer 1

You can get the number of processors available to the JVM like this:

Runtime.getRuntime().availableProcessors()

Calculating the optimal number of threads from the number of available processors is unfortunately not trivial however. This depends a lot on the characteristics of the application, for instance with a CPU-bound application having more threads than the number of processors make little sense, while if the application is mostly IO-bound you might want to use more threads. You also need to take into account if other resource intensive processes are running on the system.

I think the best strategy would be to decide the optimal number of threads empirically for each of the hardware configuration, and then use these numbers in your application.