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javamemory-managementramvisualvmjvisualvm

Java Used Heap RAM usage peaks, how can I avoid them?

First of all, I can't really show code, I am sorry, these software belongs to the company I work for, not me. I will try to explain my problem the best I can.

I am developing a little application based on JavaFX, that shows values in LineCharts, these are refreshed every 800ms-1000ms (0,8-1 seconds), and calls System.gc() every time I refresh (Around once every 0,8-1 seconds).

I am having RAM usage peaks every 10-20 seconds:

enter image description here In this specific example, this doesn't look like a problem, but in some cases it goes up to 700-750 MB (Making the Heap Size go up to 1.2-1.3 GB, and taking a long time to release it back to the OS).

I know about (and currently use, without noticing any huge improvement) Heap Tuning Paremeters, but I don't think these can fix the problem here, they are helping at specific points, and slightly reduce the memory consumption, but not solve the problem.

Any ideas on how can I design my code not to have these RAM peaks? I don't have a process that uses memory and releases it every 10-20 seconds, so I assume there is something else allocating and releasing that ammount of RAM (Maybe JavaFX?), JVisualVM only says int[], byte[] and char[], and I am not even using Integer values in my code (I work with Double values in this software).

Thank you all.

Solution

  • I found the solution:

    Both MrSmith42 and GhostCat pointed out that calling System.gc() doesn't really help me here. They were right, in fact, that was the problem.

    Removing System.gc() solved the problem for me

    enter image description here Thank you, MrSmith42 and GhostCat.