Java application not release memory

Question

I have java 1.3 or 1.4, my application start correctly.
I have set heap a 4Mb but process java begin consume ram, initialy start with 7MB after 12-15 hour the process have above 60% system mem (128Mb).
After 16-18 hour kernel kill process.
I have Ubuntu distribution
Thanks

Answer 1

it is difficult to address this question without having a knowledge of the application. Here are some suggestions:
(1) run the application from within Java Studio in debug mode. This will give you an idea of what is absorbing the memory. The idea here is to be able to watch your data structures grow. Any tool that allows you to do this will help. See http://developers.sun.com/prodtech/javatools/jsenterprise/index.html
for Java Studio Enterprise.
(2) the chances are very good that your application is creating some sort of Collection (Set, Hashtable, Vector, ...) and slowly adding to it. This is very common and a common cause of "memory leak".
(3) The garbage collector in Java frees memory as objects go out of scope. If the objects never go out of scope, they are never garbage collected.
(4) If you have these such objects or collections that must always be accessable, consider adding some caching mechanism (putting the data to disk) whereby keeping your datastructures smaller.
(5)Also, when you say "set the heap" I am assuming you used the -Xmx and -Xms command line options. If not, look into these.