The Resident size(as observed from top) of my process is increasing. But, the behaviour is very random. My process works on request reponse model. So when i put some request load on my process the memory starts increasing. For initial few hours (approx ~3 hrs) it increase at a rapid rate and after that increase become stable. Some time after 30 min a 16 kb increase is observed some time after 2-3 hrs. And some times an increase of even 128kb is observed. Behaviour is really random. Attached are the some graph of resident memory of process taken at interval of 10 min each.

I tried wdb in BATCH mode with my process. But, it didnot detected any leaks. It produced only heap profile files.

Is there any way to find out that the wt=hether increase is due to fragmentation? Because lot of malloc are happening in my process.
Platform is HP-UX B.11.23 on HP itanium server. I can use wdb and glance tool(I only have working knowledge of both of these )

Also, considering the fact that memory increase is after 2-3 hr run how can i work with wdb in debugger mode. Means is it possible to automate printing the heap information and continuing from that point in gdb/wdb automatically?

First off, most implementations of malloc tend to hold onto any memory allocated by the brk() system call. None of the memory is released until the process ends.