How to free up memory?

Question

We have been facing Out of Memory errors in our App server for sometime. We see the used heap size increasing gradually until finally it reaches the available heap in size. This

Answer 1

If you run under the Sun 6 JVM strongly consider to use the jvisualvm program in the JDK to get an inital overview of what actually goes on inside the program. The snapshot comparison is really good to help you get further in which objects sneak in.

If Sun 6 JVM is not an option, then investigate which profiling tools you have. Trials can get you really far.

It can be something as simple as gigantic character arrays underlying a substring you are collecting in a list, for e.g. housekeeping.