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[netCDFPerl #DPK-277567]: netcdf-perl and netCDF 4

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  • Subject: [netCDFPerl #DPK-277567]: netcdf-perl and netCDF 4
  • Date: Fri, 02 Mar 2012 16:05:42 -0700
Hi Andy,

> I had a follow-up conversation with our systems administrator, and he was
> wondering when version 4.2 is likely to acquire stable status, and if you
> believe that our netCDF file processing could result in erroneous results
> because of this netCDF ID bug.

We expect 4.2 to be released in a couple of weeks, without much change from
the current 4.2-rc2 release candidate, but unanticipated problems are always
possible with such software, so I can't commit to a certain date.

I don't believe your netCDF file processing, as you have described it, could
result in bad results.  The netCDF ID is an in-memory run-time handle on an
open file, which is never written to disk.  As soon as a negative netCDF ID
is detected, I expect the library would return an error corresponding to an
invalid ID, and your processing would stop.  So other than the restriction to 
process no more than 2**16 files at a time, I can't see any problem with
waiting until the netCDF-4.2 release.  The fact that you are using perl should
not be relevant, as perl just calls the C library.

--Russ

> address@hidden> wrote:
> 
> > Hi Andrew,
> >
> > That problem is fixed in netCDF version 4.1.3 and perhaps earlier versions.
> > Now ncids of closed netCDF files are reusable.
> >
> > It's only a 16-bit quantity becasue the ncid identifies both the open file
> > ID
> > and the group ID within the file, for netCDF-4 files, and the two 16 bit
> > IDs
> > are packed into one ncid.
> >
> > If you're going to upgrade your netCDF version, may I suggest trying the
> > release
> > candidate for version 4.2?  It's got lots of bug fixes as well as some
> > performance
> > improvements:
> >
> >  ftp://ftp.unidata.ucar.edu/pub/netcdf/netcdf-4.2-rc2.tar.gz
> >
> > or from the netCDF distributions page:
> >
> >  http://www.unidata.ucar.edu/downloads/netcdf/netcdf-rc
> >
> > Installation instructions are here:
> >
> >  http://www.unidata.ucar.edu/netcdf/docs_rc/building.html
> >
> > --Russ
> >
> > Russ Rew                                         UCAR Unidata Program
> > address@hidden                      http://www.unidata.ucar.edu
> >
> >
> >
> > Ticket Details
> > ===================
> > Ticket ID: DPK-277567
> > Department: Support netCDF
> > Priority: Normal
> > Status: Closed
> >
> >
> 
> 

Russ Rew                                         UCAR Unidata Program
address@hidden                      http://www.unidata.ucar.edu



Ticket Details
===================
Ticket ID: DPK-277567
Department: Support netCDF
Priority: Normal
Status: Closed