[Beowulf] Users abusing screen

Prentice Bisbal prentice at ias.edu
Fri Oct 21 06:10:18 PDT 2011


Beowulfers,

I have a question that isn't directly related to clusters, but I suspect
it's an issue many of you are dealing with are dealt with: users using
the screen command to stay logged in on systems and running long jobs
that they forget about. Have any of you experienced this, and how did
you deal with it?

Here's my scenario:

In addition to my cluster, we have a bunch of "computer servers" where
users can run the programs. These are "large" boxes with more cores
(24-32 cores) and more RAM (128 - 256 GB, ECC) than they'd have on a
desktop top.

Periodically, when I have to shutdown/reboot a system for maintenance,
I find a LOT of shells being run through the screen command for users
who aren't logged in. The majority are idle shells, but many are running
jobs, that seem to be forgotten about. For example, I recently found
some jobs running since July or August that were running under the
account of someone who hasn't even been here for months!

My opinion is these these are shared resources, and if you aren't
interactively using them, you should log out to free up resources for
others. If you have a job that can be run non-interactively, you should
submit it to the cluster.

Has anyone else here dealt with the problem?

I would like to remove screen from my environment entirely to prevent
this. My fellow sysadmins here agree. I'm expecting massive backlash
from the users.


-- 
Prentice


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