I have recorded the performances of an angular 4.4 app and I think that what the Chrome dev tools returned me about the js heap could be worrying, but I honestly lack on this subject.
I don't understand the straight drop at ~20000ms, the straight line soon after and the other drop at ~60000ms: what are they due to? Are those behaviours normal or do they means that something should be fixed?
The incline means that the page was allocating memory in the JS heap. This is normal.
The drops mean that the browser freed up memory in the JS heap that was no longer needed. This is called garbage collection. That's normal, too. Nothing alarming about that.
In general, if you see that the total amount of memory is progressively increasing after each garbage collection event, then that's a warning sign that you have a memory leak. The memory leak pattern usually looks like this:
As you can see from the graph, if you leave the page running for long enough, eventually it will use up all of the computer's memory, causing the computer to run slowly, or crash.
See Fix Memory Problems for more techniques for analyzing memory usage.
