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[netCDF #QQH-711349]: Issue reading a 4D data from a URL

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  • Subject: [netCDF #QQH-711349]: Issue reading a 4D data from a URL
  • Date: Wed, 25 Apr 2018 14:43:29 -0600
It turns out that some DAP2 servers put limits on the amount
of data they are willing to send. In fact since this is a thredds
server, it definitely has such limits.

By my calculations, you
are asking for the whole "u" variable whose size is
 2393 * 1 * 719 * 1440 * 4 = 1320531328
The last *4 is for the size of a float, which is 4 bytes.
The error message says: Request too big™10.46592 Mbytes...
My guess is that them maximum size request must be less
than 10.46.. megabytes. Your request is for some 1.3 gigabytes
(if my math is correct).

In any case, you will either need to read the variable in pieces
or ask the server administrator to up the maximum size. My guess is
that they will not accommodate you so you will have to read the variable
piece-meal. 

> Adding the error message here:
> 
> syntax error, unexpected WORD_STRING, expecting WORD_WORD
> context: Error { code = 403; message = "Request too big™10.46592 Mbytes, 
> maxP0.0" ^;};
> Error: NetCDF: Access failure
> 
> Thanks,
> Upanita
> From: Upanita Goswami
> Sent: Wednesday, April 25, 2018 11:49 AM
> To: 'address@hidden' <address@hidden>
> Cc: Ellen Johnson <address@hidden>
> Subject: Issue reading a 4D data from a URL
> 
> Hello NetCDF folks!
> 
> I am a developer at MathWorks working in the NetCDF Area.
> 
> I came across an issue in the NETCDF library recently when trying to
> use "nc_get_var_float" to read a variable from a URL. The variable is
> 4-dimensional.
> 
> I am attaching the code "main.c" that reproduces the issue.
> 
> Please note that we are using netCDF-C version 4.3.3.1. Can you please
> confirm if this is a bug in the library or am I missing some steps prior
> to reading the variable?  If you confirm this as an issue, please let
> me know if there is any workaround for this.
> 
> Thanks,
> Upanita
> 
> 
> 

=Dennis Heimbigner
  Unidata


Ticket Details
===================
Ticket ID: QQH-711349
Department: Support netCDF
Priority: Normal
Status: Open
===================
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