How to get memory usage of a Minecraft server?

Question

I am creating a Minecraft control panel at the moment and having trouble by getting the memory usage of the process.

My current process:

• launch the server in a screen
• get the pid of the screen
• fetch amount of ram with command ps -p <pid> -o %mem

The error is, that it is always showing me a usage of 0.0 KB

I'm using Debian Linux.

Any ideas?

Solution

That's because the pid that you're searching is the pid of screen. The minecraft jar should have a ppid (parent pid) of the screen, so run:

ps -el | grep <pid of screen>

you should get something like:

root@ubuntu:~# ps -el | grep 26270
5 S     0 26270     1  0  80   0 -  6797 poll_s ?        00:00:00 screen
4 S     0 26271 26270 49  80   0 - 1026274 futex_ pts/0  00:00:15 java

where 26271 is the pid of the process inside of the screen

Comments

[Fabo.sk]

Have you tried using 'top' command?

[Tillman32]

Why would you want to report mem usage off of the screen pid, and not the Minecraft server pid? @Fabo.sk - Top is great as an end user display, but not great for use in scripting.

[NickoLimited]

@Tillman32 but how do I get the Minecraft server pid? I was looking for about 4 hours now..