When the GUI Was So Slow, I Thought It Was last breath before dying

The other day, I ran into a strange problem. I opened the API Manager GUI (the user interface), and it did work… but wow, it was slow. Like, really slow. Click, wait… wait some more… then finally something would happen. It wasn’t frozen, just moving like it had no energy.

At first, I thought maybe the system was just busy. But after a few minutes, it was clear — something wasn’t right.

So, I SSH into APIM machine and checked the logs by running this command:

debug tail -f /var/log/cmc.out

And guess what showed up?

java.lang.OutOfMemoryError: Java heap space

That message means the Java program ran out of memory. It didn’t have enough space to create new objects, so everything started slowing down. The system was still alive — just barely.

Now, this kind of error doesn’t always mean something is leaking memory. Sometimes, the memory size (called heap size) is just too small for what the system is trying to do.

A Quick fix?

To get things working again quickly, I just restarted the machine by running below command. That cleared up the memory and made the GUI fast again.

To restart the machine: system restart
To show the status of restart: system show status

But here’s the real fix

If this keeps happening, it means the system needs more Java heap space. You can increase the heap size so the program has more memory to work with. That way, things will stay fast and smooth — no more slow clicks.