Experimental Physics and
Industrial Control System

Michael Davidsaver via Tech-talk <tech-talk at aps.anl.gov> · Thu, 18 Nov 2021 09:49:01 -0800

On 11/18/21 1:25 AM, Jokinen Antti (F4E) via Tech-talk wrote:
> Hi all,
> 
>  
> 
> We have established a remote server for users to connect from their home. The remote server itself is pretty beasty machine and all of its CentOS tools,

How does "pretty beasty" translate into specs?

wrt. RAM how much is each java process being allowed?  aka. the -Xmx... argument.

You can divide 3/4 total RAM size by this and estimate a limit on concurrent
java processes before swapping must happen (at which point performance will
degrade).

> Firefox and other applications are working as expected when connected via X2GO to it.

Could you expand on "Firefox and other applications are working as expected".
Do you mean in a situation where every user is simultaneously running both firefox and phoebus?

> However there is something strange going on with CSS (both Eclipse and Phoebus). If there are only a few users on the server logged on remotely, CSS works pretty smoothly but once the user count goes higher e.g. up to 15 or so, something gets sticky and CSS basically slows down (on all users) to being unusable.

Does "user count" mean number of cs-studio processes?  number of windows?  number of users logged in?

> The server key parameters (total server CPU usage <10%, RAM 80% free) are all green. It looks like the problem is not coming from these.

When you say "RAM 80%" free.  What specific metric are you referring to?
Allocated virtual memory?  resident memory?  Does this include swap?

Also, are you looking at network bandwidth utilization?

Are there any network filesystem mounts involved?

> My question is that what could be causing the slowdown? Is there something we have overlooked? Could it be JAVA? HDD/network?
> 
>  
> 
> Thanks a lot!
> 
> Antti  (IFMIF)
> 

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System