20000103: Y2K bug in LDM (fwd)

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Robb Kambic                                Unidata Program Center
Software Engineer III                      Univ. Corp for Atmospheric Research
address@hidden             WWW: http://www.unidata.ucar.edu/
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---------- Forwarded message ----------
Date: Mon, 03 Jan 2000 08:56:18 -0700
From: Unidata Support <address@hidden>
To: address@hidden
Subject: 20000103:  Y2K bug in LDM


------- Forwarded Message

>To: address@hidden
>cc: address@hidden
>From: address@hidden (Peter Neilley)
>Subject: Y2K bug in LDM
>Organization: .
>Keywords: 200001031546.IAA07174

Robb et al.:

  I'll report this as a matter of fact, not needing any action.

  We saw an interesting behaviour in pqact and pqsurf near the 00Z transition 
to Y2K.  We
  run v5.0.8 of the LDM on our Solaris ldm machine "ofour.rap.ucar.edu" which 
had the
  last-minute Y2K patches installed.  Nearly all of the files written out by 
pqact and 
  pqsurf on this machine are written to files with a pathname template like:

                 /weather/ddp/(\1:yyyy)(\1:mm)\1/(\1:yyyy)(\1:mm)\1\2.type

  where "type" is replaced with something appropriate for the data type.  For 
example, the
pqact entry for our ascii filing of METAR reports is:

WMO     ^S[APX].* .... ([0-3][0-9])([0-2][0-9]) FILE    
/weather/ddp/(\1:yyyy)(\1:mm)\1/(\1:yyyy)(\1:mm)\1\2.METAR

Note that both a subdirectory and filename contain the year,month and day.

  The bug we noted is that for all bulletins that were dated in the year 2000 
(e.g. a WMO
header like "SAUS70 KWBC 010000") but arrived *before* 00 UTC of 01 Jan, they 
were 
written to files with pathnames like:

               /weather/ddp/20000101/1999120100.METAR

That is, the first subdirectory was correctly dated in the year 2000, but the 
filename
was still given Dec, 1999.  

I was logged on watching things at 00Z New Year's eve.  The above problem went 
away in pqact
soon as 00 UTC arrived when files became properly named.  However, pqsurf 
continued to write
files with the 1999 year in them at least through 0200 UTC.  AT that point, I 
restarted pqsurf 
and the problem cleared up.

  We have a couple dozen files in our /20000101 subdirectory named 
199912xx..... if you're
interested in seeing which bulletins were amoungst the "confused" bunch.

  Things are running fine since.

  Happy New Year!


Peter Neilley, NCAR/RAP
address@hidden
303-497-8446



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