Anyone else see the heap usage climb even when no one is on?
Yes, and I think I see this frequently happen even on vanilla.
When servers are started in MineOS, there is a maximum amount of memory allocated to the Java instance (xmx heap size). Minecraft is free to use up to that point, so it does. It continues to use more memory as it deals with entities or literally any other work it wants or needs. And it doesn’t release that memory because it’s java’s memory–no other process can use it, so no need to unload stuff it already loaded.
Is there a problem you’re experiencing or is it just curiosity?
Just curious. Thanks