20050221: reporting of real time NEXRAD Level II statistics to Unidata

>From: Unidata Support <address@hidden>
>Organization: UCAR/Unidata
>Keywords:  200502190008.j1J08Cv2024308@ IDD real time statistics

Michael,

Bob Lipschutz advised me to contact you about real time statistics
reporting by a couple of machines at FSL:

montana.fsl.noaa.gov
slug.fsl.noaa.gov

Here is the email I sent Bob previously:

  On Tuesday, February 15 client machines' reporting of real time IDD
  statistics to the statistics server at Unidata, rtstats.unidata.ucar.edu,
  may have experienced a problem that was caused by an LDM upgrade at
  Unidata.  It appears that only Linux clients were affected.
  
  I am contacting you since we stopped receiving real time statistics
  from one or more machines at your site after the Tuesday incident.  If
  you are not the appropriate LDM/IDD contact at your site, please
  forward this email to the appropriate person.
  
  The problem, which was corrected on the Unidata side in short order,
  manifested itself in one of three ways on Linux machines reporting
  real time statistics using the LDM 'rtstats' utility:
  
  - the site experienced no interruption of service of any kind
  
    We sent you this this note since we believe that you _were_ affected.
    We base this opinion on our lack of real time statistics from one
    or more of your machines since Tuesday.
  
  - 'rtstats' experienced a hard error that caused it to exit
  
    Since 'rtstats' is part of the LDM process group, this would result
    in the LDM shutting down.  A notice was sent to the ldm-users email
    list informing IDD participants of the problem and giving detailing
    the procedure to get their systems working again.
  
  - 'rtstats' went into a tight loop causing it to use undue amounts of
    CPU on the client machines
  
    This would not affect the site's ability to ingest or relay data, but
    it would caused real time statistics to no longer be reported to
    Unidata.  We believe that you may be experiencing this problem.
  
  The best way to determine if you are experiencing the last condition
  is to run the 'top' utility and see if 'rtstats' is at the top
  of the list and has used an excessive amount of CPU time.  If it
  is not at the top of the list and is not using lots of CPU, you
  need take NO corrective action.
  
  If you do find that you have a problem, the resolution is to stop and
  restart the LDM using:
  
  <as 'ldm'>
  ldmadmin stop
  ldmadmin start
  
  We want to assure you that the version of the LDM we released
  yesterday, v6.2.1, eliminates the possibility that upgrades at Unidata
  could cause LDM exits at client sites.
  
  Please accept our sincere apologies for any problems our LDM upgrade
  may have caused you!

Regards,

Tom Yoksas
--
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