semiharge

https://github.com/MinecraftForge/MinecraftForge/issues/new has the lines So, instead of posting it there, I'm posting it here.

Posting this here as per github issue template. I've got two heap dumps from our server running the modpack snorshcraft: https://minecraft.curseforge.com/projects/snorshcraft/files/2557580 running Forge 14.23.3.2678. These heapdumps are from different days, the server was restarted in between (so the Issue happened more than once). Both show a EntityPlayerMP object for a disconnected player that's still in the net.minecraft.server.management.PlayerChunkMapEntry.players list. As a result of that Minecraft keeps the chunk loaded and keeps queuing chunk update messages for that player. As the player is disconnected these messages pipe up and take up huge amounts of memory. Path to GC Roots: The upper path is the one that's causing the issue. the lower one has already been reported to SimplyJetpacks 2 here: https://github.com/Tomson124/SimplyJetpacks-2/issues/84 . While it also keeps the object alive it doesn't cause the chunk update queuing. An interesting finding here is that the player object is no longer in the net.minecraft.server.management.PlayerChunkMap.players list, it is only in PlayerChunkMapEntry.players. This screenshot shows the memory is accumulated in net.minecraft.network.NetworkManager.outboundPacketsQueue: In this dump the queue contains one million messages that wont ever get sent. Here's a list of the different kinds of packets in the queue: I have the corresponding log for one of these 2 heap dumps. The Log lists a lot of exceptions for the timestamp corresponding to the net.minecraft.entity.player.EntityPlayerMP.playerLastActiveTime in the heap dump. The player in question gets disconnection on Dimension change after Recurrent Complex fails to generate a maze.