How to delete memory usage during an Experiment?

Question

I am constructing an experiment in Anylogic, which saves data in the Parameter variation tab under a custom-class list. The model needs to perform a lot of simulations, and repetitions to optimize for Setting variables in the model itself. After x amount of iterations, I use a Python connector to run some code in finding new possible parameters for the underlaying model.

The problem I am having right now, is that around Simulation-run number 200, the memory usage is maximum (4Gb), and it proceeds to run super-slow. I have found some interesting ways to cut on memory usage, but I believe there is only one thing that could help me right now: let the system delete memory that is used for past iterations. After each iteration, the data of a simulation is stored, so I am fine with anylogic deleting the logs of the specific simulation afterwards.

Is such a thing possible? If so, how can I implement that?

Answer 1

Java makes use of a Garbage collector to manage memory usage and you have no control over it. How it works is that every now and then, based on some internal logic, it will collect and remove all instances of classes in memory that do not contain any active references and remove them.

Thus to reduce memory you must ensure that any instances that are no longer needed are not referenced by any of the objects currently active in your model.

To identify these you must use a Java profiler like JProfiler, or some of the free alternatives - see here for more.

This will show you exactly what classes are using up all your memory and with some deep diving you should be able to identify who is keeping reference to them.