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[LDM #RMC-119248]: determining proper ldm product queue

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  • Subject: [LDM #RMC-119248]: determining proper ldm product queue
  • Date: Tue, 10 Oct 2006 10:39:37 -0600
Gail,

> We will be upgrading our LDM version from 5.0.6 to 6.4.5 very soon - in the
> next day or so. We are having problems with the product queue getting filled
> up very quickly. Is there a utility to help us create the optimal queue -
> other than letting it run for a while and using pqmon - which will be
> available to us in the new version?

I'm afraid that there's no utility that can size the product-queue for you.  
Because data-product reception is highly variable (both throughout the day and 
in the requests that each site makes) the decision on the product-queue 
parameters (size, number of slots) requires a human in the loop.

I like to use the pqmon(1) utility to sample the age of the oldest data-product 
in the queue as well as the number of slots in-use and then plot those 
parameters as a time series so I can get a good idea of what their values 
should be.  Because the default action of the LDM is to request data from one 
hour ago (when starting with an empty queue) I recommend that the age of the 
oldest product in the queue always be greater than one hour.

The attached script is useful for getting product-queue parameters.  It can be 
run by a crontab(1) entry like

    0,10,20,30,40,50 * * * * util/snapshot >>data/time-series.txt

The age of the oldest product in the queue can then be plotted by the 
gnuplot(1) utility via the attached script.

Regards,
Steve Emmerson

Ticket Details
===================
Ticket ID: RMC-119248
Department: Support LDM
Priority: Normal
Status: Closed