RAM overload with backpacks

[TwinkleToes777]

RAM overload with backpacks

[iTwins]

Please provide the entire error

[TwinkleToes777]

[Craft Scheduler Thread - 814 - Slimefun/WARN]: [Slimefun] Plugin Slimefun vDEV - 1104 (git c977454) generated an exception while executing task 4745749
java.lang.OutOfMemoryError: Java heap space
at java.util.Arrays.copyOf(Arrays.java:3537) ~[?:?]
at java.lang.AbstractStringBuilder.ensureCapacityInternal(AbstractStringBuilder.java:228) ~[?:?]
at java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:582) ~[?:?]
at java.lang.StringBuilder.append(StringBuilder.java:179) ~[?:?]
at org.bukkit.configuration.file.FileConfiguration.load(FileConfiguration.java:153) ~[purpur-api-1.19.4-R0.1-SNAPSHOT.jar:?]
at org.bukkit.configuration.file.FileConfiguration.load(FileConfiguration.java:128) ~[purpur-api-1.19.4-R0.1-SNAPSHOT.jar:?]
at org.bukkit.configuration.file.YamlConfiguration.loadConfiguration(YamlConfiguration.java:309) ~[purpur-api-1.19.4-R0.1-SNAPSHOT.jar:?]
at io.github.thebusybiscuit.slimefun4.libraries.dough.config.Config.(Config.java:89) ~[Slimefun4 - DEV 587 (git a1952).jar:?]
at io.github.thebusybiscuit.slimefun4.libraries.dough.config.Config.(Config.java:100) ~[Slimefun4 - DEV 587 (git a1952).jar:?]
at io.github.thebusybiscuit.slimefun4.api.player.PlayerProfile.(PlayerProfile.java:82) ~[Slimefun4 - DEV 587 (git a1952).jar:?]
at io.github.thebusybiscuit.slimefun4.api.player.PlayerProfile.lambda$get$5(PlayerProfile.java:406) ~[Slimefun4 - DEV 587 (git a1952).jar:?]
at io.github.thebusybiscuit.slimefun4.api.player.PlayerProfile$$Lambda$11344/0x000079951416b970.run(Unknown Source) ~[Slimefun4 - DEV 587 (git a1952).jar:?]
at org.bukkit.craftbukkit.v1_19_R3.scheduler.CraftTask.run(CraftTask.java:101) ~[purpur-1.19.4.jar:git-Purpur-1985]
at org.bukkit.craftbukkit.v1_19_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:57) ~[purpur-1.19.4.jar:git-Purpur-1985]
at com.destroystokyo.paper.ServerSchedulerReportingWrapper.run(ServerSchedulerReportingWrapper.java:22) ~[purpur-1.19.4.jar:?]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136) ~[?:?]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) ~[?:?]
at java.lang.Thread.run(Thread.java:840) ~[?:?]

[Phoenix-Starlight]

Do you mind providing the file of said player? (The file is named in UUID format, under data-storage/Slimefun/Players/<uuid>.yml)

[TwinkleToes777]

Do you mind providing the file of said player? (The file is named in UUID format, under data-storage/Slimefun/Players/<uuid>.yml)

I renamed it to .txt, because github does not support uploading .yml
slimefun-player-data-file.txt

[J3fftw1]

This aint a fun issue to solve sadly.
The quickest and dirtiest way is to delete the file or shorten it.

[Phoenix-Starlight]

Hey, so I don't believe the extremely hefty file is the cause of your OOM. The string at most will occupy 21MB, which implies that your server is already nearing the max heap limit.
I'd suggest you check via a heapdump on OOM (-XX:+HeapDumpOnOutOfMemoryError).

[TwinkleToes777]

so I finally was able to track down this problem, it happens with any backpack at all, it doesn't even have to be a big player file, it just needs opening the backpack many times in a short time.
I used this JVM flag: -XX:+HeapDumpOnOutOfMemoryError
then I analyzed it with Eclipse Memory Analyzer and the result was that 7.4gb ram is used by something unlabeled, but going in details it says that it's used by Thread, and there are very many slimefun threads, so I'm guessing it's caused by spawning very many threads in a short time

[J3fftw1]

Send us the dump please

[TwinkleToes777]

Send us the dump please

my internet is very slow (under 1 mb/s) so sending the dump is not really an option, it also contains sensitive info such as passwords, but I can provide screenshots of desired areas in Eclipse Memory Analyzer

[J3fftw1]

Without info we can’t do much

[TwinkleToes777]

for the time being, disabling backpacks and using a slimefun addon that adds "backpack unloader" machine, is my solution to this problem