Memory Heap "flushing" every 2 minutes. Normal or sign of a problem?

Hi,

independent of which server version we are using (3.x, 4.x), the following occurs:

image

image

The Memory Heap is "flushing" each 2 minutes. Is this normal behavior (for example garbage collection) or is this sign of a problem? It needs only a few web pages to be requested until the heap size reaches 2/3 of the max. heap size configured.

With kind regards,
Sven