What is the recommended heap size configuration for Jboss AS 6 when running a VM with multiple instances?

iwitham Mar 26, 2013 4:23 PM

I am new at Jboss and need to tune an instance of Jboss AS 6 so that we eliminate the out of memory issues. Currently we have our heap sizes set to a minimum heap setting of 512mb and a max of 1024mb. The original setup of the VM was 2 CPU's and 2GB of RAM. I have had our IT group upgrade it to 4 CPU's and 8GB or RAM. Prior to the upgrade I was able to get 4 instances running concurrently, but they were very slow. We were utilizing swap since Jboss was using 1.3GB of the allocated 2GB. Now that we have upgraded I am able to run 10 concurrent instances and it was beginning to utilize swap space again. I will need to have 15 instances running concurrently so it is very important to optimize the heap. If there are additional things that I can tune I am open to suggestions.

Thanks,

Iry

1. Re: What is the recommended heap size configuration for Jboss AS 6 when running a VM with multiple instances?

peterj Mar 26, 2013 6:27 PM (in response to iwitham)

Have you done any load testing on your applications, gathering garbage collection data, to determine the optional heap sizing?

I usually recommand that "installed RAM" == "total max size of all heaps". Thus if you want 15 instances with max heap of 1GB for each, you need 15GB RAM. Now, the memory used by a Java process is more than just the heap (there's lots of other stuff also), but considering that part of the heap is always empty, it usually works out that the memory the Java apps need is in RAM.
1 of 1 people found this helpful
Actions