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Re: 20020917: CPU & Memory vs. Performance (LDM)

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  • Subject: Re: 20020917: CPU & Memory vs. Performance (LDM)
  • Date: Tue, 17 Sep 2002 15:59:54 -0600 (MDT)
Hi Bunny,

The optimal amount of memory is slightly larger than your queue.

The LDM will run "best" if the entire queue can reside in memory.

For example we have a 7GB queue on our feed machine and 8GB of memory.

Nice work splitting your feeds, as I am sure you noticed in the archives,
that can increase performance by decreasing latencies.

Hope this helps!

Cheers,

-Jeff
____________________________                  _____________________
Jeff Weber                                    address@hidden
Unidata Support                               PH:303-497-8676 
COMET Case Study Library                      FX:303-497-8690
University Corp for Atmospheric Research      3300 Mitchell Ln
http://www.unidata.ucar.edu/staff/jweber      Boulder,Co 80307-3000
________________________________________      ______________________

On Tue, 17 Sep 2002, Unidata Support wrote:

> 
> ------- Forwarded Message
> 
> >To: address@hidden
> >From: Bunny Pfau <address@hidden>
> >Subject: CPU & Memory vs. Performance (LDM)
> >Organization: UCAR/Unidata
> >Keywords: 200209171959.g8HJxk112107
> 
> 
> Is there a document (I've been searching the UNIDATA web site)
> that deals with suggested CPU, memory amount to help LDM 
> run at its most efficient level?
> 
> I have an upstream server serving our own in-house data to
> a couple of downstream servers---I mainttain them all.
> I'm in the process of trying to squeeze out every last
> ounce of speed I can. 
> 
> I'm on the Solaris 7 platform, on Sun SPARC hardware.
> 
> I increased my setup so that I have THREE downstream clients
> running ldmd and saw that I could increase the data transfer
> rate by doing that..
> 
> I've also read through the email archives, noting in some
> emails that memory is VERY important.
> 
> Say I have my main, upstream server with a 600MB queue,
> at any time finding it to have 400-600MB of data on it..
> What would be the recommended ratio of memory to queue size
> for a Solaris 7 server (currently it has a measley 128MB of
> RAM on it and with three downstream clients requesting data,
> I can get up to an 8.2MB/minute transfer rate).
> 
> Any help or referring me to the place in documentation which
> might be helpful would be great.
> 
> Thanks,
> Bunny
> 
> ---
> 
> Bunny Pfau                      National Center for Atmospheric Research
> address@hidden                  High Altitude Observatory
> tel: 303 497-1555               P.O. Box 3000
> fax: 303 497-1589               Boulder, CO  80307-3000
> 
> 
> 
> 
> 
> 
> ------- End of Forwarded Message
> 
>