@girish How does this affect running apps of an upgraded system?

Only newly installed apps get the new allocation %. Existing apps run with 50% as before. If you want to change it, you can just adjust the memory of the app a bit and it will reallocate with new strategy.

Is there a new default?

Cloudron allocates 50% of this value as RAM and 50% as swap.

In 6.1, we have changed this strategy. Cloudron now allocates the % based on the system's proportion of RAM and Swap. We found that when a server has lots of memory, it was still busy swapping because we always allocated 50-50.

I've tried to fixup the app to dynamically adjust the java memory: https://git.cloudron.io/cloudron/minecraft-app/-/commit/1d86c23c59c04d343bd35c112722b22fb33c9e6d

I also uploaded a version to test this with https://my.<domain.com>/#/appstore/net.minecraft.cloudronapp?version=1.3.7

Would be good to get feedback if this is the fix you expected, then I can make a package release.

Hmm
When setting the App to 10G Memory with cloudron I get this

Feb 02 22:50:38 start minecraft server with memory limit 5120 M

Which is kinda correct since

Cloudron allocates 50% of this value as RAM and 50% as swap.

But still feels a bit misleading.

@nebulon I've deployed that version and it looks good to me. Thanks for your work! I'll keep an eye on the server once the package is released and if the server crashes again I'll be able to see in the crash report how much memory it was using at the time.

I also uploaded a version to test this with https://my.<domain.com>/#/appstore/net.minecraft.cloudronapp?version=1.3.7

Would be good to get feedback if this is the fix you expected, then I can make a package release.

Here with the line you mentioned:
https://git.cloudron.io/BrutalBirdie/papermc-minecraft-app/-/blob/feature/v1.6.5/backend/minecraft.js#L28
(Custom app with paper mc instead of vanilla since I want some plugins )

Also I am not 100% sure if it needs to be updated at all.

I also followed the Tuning the JVM – G1GC Garbage Collector Flags for Minecraft guide from the creator of PaperMC (but scrapped the -XX:+AlwaysPreTouch due to crashing.)

Also noting that with Minecraft 1.17 release the openjdk-8-jdk-headless need to upgraded to openjdk-11-jdk-headless which I tried and ended up with a non working app, so I switched back to openjdk-8-jdk-headless

Context: https://forum.cloudron.io/topic/3588/frequent-java-lang-outofmemoryerror-java-heap-space-errors/5?_=1612137576983
Fix (for Metabase): https://git.cloudron.io/cloudron/metabase-app/-/blob/master/start.sh#L38-42

cc @girish