Severe memory issue and crash with ViaVersion on Paper 1.14

Describe the bug Big memory issue (crash and can’t connect) when connecting from Geyser (Builds 162, 161, 160) to a Java 1.14.4 Paper based server (latest build of 1.14.4 paper) that is using ViaVersion 2.2.3, and is under a BungeeCord proxy hosted on the same machine.

When i connect (using Geyser online mode) to the server, the proxy sees my account trying to connect, it succesfully autenticates with Mojang credentials and then it idles for a while. Meanwhile the player start falling in the void, lagging. Then Geyser crashes.

I am hosting Geyser on a separated VPS by Hetzner, 2gb of ram. Startup flags are simply: java -Xmx1G -Xms2G -jar Geyser.jar

When connecting it reaches 2g of ram and Ubuntu kills the process instantly, since the vps has only 2gb of ram. If i allocate xmx1gb and xms1gb then it reaches 1gb and crashes, without being killed by ubuntu.

I also tried to host Geyser on my laptop allocating 5 gb of ram or more, freezes anyway and the server kicks me out for various reasons (Lost connection, timeout, …)

To Reproduce Make a similar setup to mine:

• Geyser hosted on vps
• Java hosted on dedicated ovh, on paper 1.14, under BungeeCord
• Disable any eventual anti ddos service (i had TCP Shield completely disabled, connected via clear ip)
• Disable every plugin made exception for ViaVersion
• Connect with mcpe on android to geyser
• Authenticate with mojang credentials
• Wait for the crash

Expected behavior I tried to point my Geyser installation to a random 1.15 server, and it worked quite nice. You did an incredible job so far, only if it wasn’t that it isn’t working for my server!

Screenshots / Videos

Server Version Paper version git-Paper-243 (MC: 1.14.4) (Implementing API version 1.14.4-R0.1-SNAPSHOT)

Geyser Version Standalone (Builds 162, 161, 160), floodgate was installed on the bungeecord but the auth on geyser was set to online anyway.

Minecraft: Bedrock Edition Version 1.14.60 android and ios (ipad)

Additional Context All plugins disabled made exception for ViaVersion. Bungeecord had floodgate enabled while testing but Geyser was set to online mode anyway. TCP Shield disabled and using clear ip.

[Camotoy]

-Xmx1G -Xms2G don’t these flags mean that you have a maximum of 1GB and a minimum of 2GB? If you were able to get it working anyway that may not be the problem but try switching them around anyway.

[danielboos1]

I recommend setting them both the same value. Here is why…

In a production environment, if you monitor the GC data, you will notice that is a relatively short period of time (usually less than an hour), the JVM will eventually increase the heap size to the -Xmx setting. Each time the JVM increases the heap size it must ask the OS for additional memory, which takes time (and thus adds to the response time of any requests that were is process when the GC hit). And usually the JVM will never let go of that memeory. Therefore, since the JVM will eventually grab the -Xmx memory, you might as well set it to that at the beginning.

Another point is that with a smaller heap size (starting with -Xms), GCs will happen more often. So by starting with a larger heap initially the GCs will happen not as often.

Finally, in a production environment, you usually run only one app server per OS (or per VM). So since the app server is not competing for memory with other apps you might as well give it the memory up front.

Note that the above is for production. It applies also to the syatem test environment since the system test environment should mimic production as close as possible.

For development, make -Xms and -Xmx different. Usually, you are not doing much work with the app server in development, so it will often stay with the -Xms heap setting. Also, since in development the app server will share the machine with lots of other apps (mail client, word processors, IDEs, databases, browsers, etc), setting the -Xms to a smaller size lets the app server play more nicely with the other software that is also competing for the same resources.