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Re: 20000502: Using pq_insert when LDM isn't running (fwd)

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  • Subject: Re: 20000502: Using pq_insert when LDM isn't running (fwd)
  • Date: Wed, 03 May 2000 14:31:57 -0600
Gregory Grosshans wrote:

> Anne Wilson wrote:
>
> ...text deleted...
>
> > But, I guess my real question is (which I should have asked yesterday), why 
> > are you
> > stopping the LDM to copy your metar file?   You can get it out of your own 
> > queue by
> > using 'pqcat' or you can have your LDM dump it to stdout when it arrives 
> > using
> > 'feedme'.  Would either of these solve your problems?  If so, then you 
> > could have the
> > LDM start your acqserver thereby reaping the improved efficiency and you 
> > would not need
> > to shut anything down.
> >
> > ...text deleted...
>
> Thanks for the information.  I should have been more specific when I 
> mentioned copying the
> metar file.  In this case there are two machines running LDM and 
> NAWIPS/GEMPAK.  LDM kicks
> off dcmetr when data comes in.  Once in a while the metar gempak file on 
> machine A becomes
> corrupted, though its still fine on machine B.   The metar gempak file is 
> corrupted and
> accessing a certain hour (i.e. when it became corrupted) results in a 
> segmentation fault.
> To provide all of the metar data for the day to the forecasters I stop LDM on 
> machine A,
> then stop LDM on machine B.  I then FTP the metar gempak file from machine B 
> to A.
> Finally I start LDM on both machines.
>
> The metar gempak file becomes corrupted when two dcmetr processes are spawned 
> and writing
> to the same gempak file.  From previous emails with Steve and Robb and 
> talking to the
> local sys admin this corruption occurs when the PIPEs become full as a result 
> of so much
> disk I/O.  The corruption sometimes occurs around the time of the 00Z or 12Z 
> model ingest.
>
> Gregg

Yes, I do remember hearing a little about this.  Thanks for filling me in.

Unless I hear from you again I'll assume you're ok.

Anne

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Anne Wilson                     UCAR Unidata Program
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                                  Boulder, CO  80307
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