Re: [ldm-users] Product queue size

• To: Matthew Foster - NOAA Federal <matthew.foster@xxxxxxxx>
• Subject: Re: [ldm-users] Product queue size
• From: Karen Cooper - NOAA Affiliate <karen.cooper@xxxxxxxx>
• Date: Fri, 3 Feb 2017 08:14:12 -0600

Hi Matt,

I have not noticed any runtime slow down when using larger queues with
LDM.   I have queues of 8GB and 12GB and have not had any problems with
them.

The only time I have noticed an effect from the larger queues is when
stopping LDM.

I'm not 100% sure but as if I understand correctly; when running, the queue
is all kept in RAM, so IO is not typically an issue, but if you stop it
flushes to disk, and that can take some time with larger queues and
sometimes it goes awry.

So, if you are stopping and starting a lot, it could have an impact.

I've also talked with other LDM users about running multiple instances of
LDM with discrete queues, but I have never actually done it myself.


On Fri, Feb 3, 2017 at 7:59 AM, Matthew Foster - NOAA Federal <
matthew.foster@xxxxxxxx> wrote:

> I have heard that a very large product queue can start incurring so much
> overhead to maintain that it can slow LDM down noticeably.  I have not,
> however, found anything in writing saying as much via Google searches.
>
> We're in a situation where our 4GB PQ is dropping down to a max age of
> around 5 minutes at times.  We're trying to decide if we just keep
> increasing the size of the queue or look for other solutions.
>
> We welcome any input!
>
> Matt
>
>
> --
> Matt Foster
> Techniques Development Meteorologist
> NWS Central Region Headquarters, Scientific Services Division / STI
> Kansas City, MO
> Office: 816-268-3113
>
>
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-------------------------------------------
Karen.Cooper@xxxxxxxx

Phone#:  405-325-6456
Cell:   405-834-8559
National Severe Storms Laboratory

• References:
  • [ldm-users] Product queue size
    • From: Matthew Foster - NOAA Federal