Claude Moore wrote:Heap space depends upon how much memory your program consumes. A single user consuming all available memory may sink your program as well.
128 MB it's quite a few memory amount, I would start with 1/2 GB.
To measure heap consumption I would avoid self-made solutions. I would use for example JConsole or JVisualVM, shipped with JDK (and / or JRE, I don't remeber).
thanks for answer , but i used Jconsole , but in local just me use my web application , and Jconsole shows consuming of heap space in order to one user , but i want to test it in real condition , such as 100 or 1000 users .