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[LDM #UYH-624598]: LVS realserver switching loses data

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  • Subject: [LDM #UYH-624598]: LVS realserver switching loses data
  • Date: Sat, 28 Oct 2006 10:41:17 -0600
Hi Art,

I saw the following from you regarding the request lines you are using
on your test system:

> Test system ldmd.conf request lines:
> 
> request PPS     ".*"    ldm.meteo.psu.edu
> request DDS     ".*"    ldm.meteo.psu.edu
> request IDS     ".*"    ldm.meteo.psu.edu
> request FSL2    ".*"    ldm.meteo.psu.edu
> request DIFAX   ".*"    ldm.meteo.psu.edu
> request MCIDAS  ".*"    ldm.meteo.psu.edu
> request NIMAGE  ".*"    ldm.meteo.psu.edu
> request HDS     ".*"    ldm.meteo.psu.edu
> request CONDUIT ".*"    ldm.meteo.psu.edu
> request NGRID   ".*"    ldm.meteo.psu.edu
> request SPARE   ".*"    ldm.meteo.psu.edu
> request NEXRAD  ".*"    ldm.meteo.psu.edu
> request FNEXRAD ".*"    ldm.meteo.psu.edu
> request NEXRD2  "L2-BZIP2/(KCCX|KPBZ|KDIX|KBGM|KLWX|KBUF|KCLE)" 
> ldm.meteo.psu.edu
> request NLDN    ".*"    ldm.meteo.psu.edu
> request WSI     ".*"    ldm.meteo.psu.edu
> request GEM     ".*"    ldm.meteo.psu.edu
> request NOGAPS  ".*"    ldm.meteo.psu.edu

I just wanted chime in with the following comments:

1) separate requests for PPS, IDS, and DDS are not needed.  Each request
   will actually get the exact same set of data as the others, so one
   request would suffice and is more efficient.  I suggest:

request IDS|DDPLUs     ".*"    ldm.meteo.psu.edu

2) when feeding multiple streams from a machine on the local network, it
   is usually a good idea to combine as many of the feed requests as
   possible.  For instance, in our LVS cluster, we have two "collector"
   machines that redundantly request all data feeds from a number of
   downstream hosts.  On the cluster's real servers, we have only two
   request lines, one to one collector and the other to the other collector:

request ANY ".*" oliver.unidata.ucar.edu
request ANY ".*" emo.unidata.ucar.edu

3) since I was not involved in the discussion you and Steve have been having
   (preparing for my McIDAS workshop that starts Monday morning), it may
   well be that your set of requests was designed to stress ldm.meteo.psu.edu
   by adding a number of additional feed requests.  If this is the case, please
   ignore this email :-)

Cheers,

Tom
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Ticket Details
===================
Ticket ID: UYH-624598
Department: Support LDM
Priority: Normal
Status: Closed