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20030212: CONDUIT feed pattern change

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  • Subject: 20030212: CONDUIT feed pattern change
  • Date: Wed, 12 Feb 2003 13:10:43 -0700
>From: Unidata Support <address@hidden>
>Organization: UCAR/Unidata
>Keywords: 200212271733.gBRHXAt25394 LDM 6 regular expression

Hi Harry,

Profiling of the LDM has revealed a major bottleneck in the regular
expression code on Sun Solaris (both SPARC and x86).  In particular,
Steve Emmerson determined that a Sun will work a lot harder (something
like a factor of 1300) with split feed requests that look like:

request CONDUIT    ".*[09]$"   thelma.ucar.edu
request CONDUIT    ".*[18]$"   thelma.ucar.edu
request CONDUIT    ".*[27]$"   thelma.ucar.edu
request CONDUIT    ".*[36]$"   thelma.ucar.edu
request CONDUIT    ".*[45]$"   thelma.ucar.edu

than the following feed requests:

request CONDUIT    "[09]$"   thelma.ucar.edu
request CONDUIT    "[18]$"   thelma.ucar.edu
request CONDUIT    "[27]$"   thelma.ucar.edu
request CONDUIT    "[36]$"   thelma.ucar.edu
request CONDUIT    "[45]$"   thelma.ucar.edu

Steve is investigating H. Spencer's regular expression package to see
if using it on Sun gets rid of/mitigates this bottleneck.  Until
then, we are requesting that you change your CONDUIT feed requests on
marzipan to the second set listed above and then stop and restart your
LDM.

Also, if you are game, you could load in the latest version of the LDM
and use it instead of the LDM6 release candidate you are now using.
(The current LDM6 candidate as of a couple days ago is ldm-6.0.0.16).
I have to warn you, however, that new versions will definitely be
coming down the pike, so there will be needed upgrades in the
near future.

Thanks in advance...

Tom