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[THREDDS #IUW-128695]: Problem with THREDDS aggregated datasets



Hi Carl,

Just to make sure I understand. You have a Hyrax server setup to serve the 
individual data files and then a THREDDS Data Server (TDS) setup to serve the 
aggregated datasets. Is that right?

It looks like they are both on the same machine. Are they running under the 
same Tomcat installation and instance?

The "403 Forbidden" response is from the Hyrax server. Which means the request 
was understood but the server has decided not to provide the response. I'm 
wondering if the Hyrax server is restricting access because it is under heavy 
load or getting "too many" requests from a single client (your second request 
would hit it with 200 separate requests). I don't see anything in the 
Hyrax/OLFS code that indicates it would restrict access. Do you know if the BES 
has this kind of access control?

Have you looked at the Hyrax logs? I would guess they are in 
${TOMCAT_HOME}/content/opendap/logs. There might be some clues in there.

Hope this helps,

Ethan

 

> I've aggregated several of our local Pathfinder SST datasets and made
> the aggregations accessible on our THREDDS catalog.  These are large
> time series being aggregated with a time array as much as 20,000 on some
> of the daily collections.  This is an example of the OPeNDAP form
> displayed for one of the aggregations from the THREDDS catalog.
> 
> http://satdat1.gso.uri.edu/thredds/dodsC/NWAtlanticDec_1km.html
> 
> I've tried to retrieve some data in ASCII by checking the box for
> dsp_band_1 and filling in the parameters for time, lat and lon on this
> OPeNDAP form.  When I put in a small time interval like 1000:1020 and
> lat,lon intervals of 1000:1010 and retrieve the ascii ("Get ASCII") I am
> able to get the data.  But when I do a larger time interval like
> 1000:1200 I can get an error message like this one, instead of receiving
> data:
> 
> Error {
> code = -1;
> message =
> "http://satdat1.gso.uri.edu/opendap/Pathfinder/Northwest_Atlantic/1km/declouded/1986/3/k86079070858.hdf
> HTTP/1.1 403 Forbidden";
> 
> It is problematic because when I repeat the  same data request,
> sometimes I get the data and other times I will get the error message.
> And the error message always references a different data file, never the
> same one.  I don't think it is function of the aggregation gagging on
> some bad data files because I am sometimes able to retrieve the same
> data.  Also, it does not appear to be a memory problem because we upped
> the memory for the server, first to 1gb and even to 2 gb and we still
> had the same problems.  That should be more than sufficient memory to
> handle this size request.  Somehow in the process of serving out the
> larger data request, the BES is getting flooded and sometimes unable to
> complete it.   I am wondering if this is a problem with how we set
> things up on the BES hyrax which is causing it to gag on large data
> requests?
> 
> I looked at the catalina.out file and found these entries, relating to
> one of these failed attempts:
> 
> Sending OPeNDAP ASCII Data For: ReqState:
> serverClassName:    'thredds.server.opendap.NcDODSServlet'
> dataSet:            'NWAtlanticDec_1km'
> requestSuffix:      'ascii'
> CE:                 'dsp_band_1[1000:1200][1000:1010][1000:1010]'
> compressOK:          true
> InitParameters:
> DebugOn: ''
> maxNetcdfFilesCached: '10'
> CE: 'dsp_band_1[1000:1200][1000:1010][1000:1010]'
> DODServlet ERROR (anyExceptionHandler): java.io.IOException:
> http://satdat1.gso.uri.edu/opendap/Pathfinder/Northwest_Atlantic/1km/declouded/1986/3/k86079070858.hdf
> HTTP/1.1 403 Forbidden
> ReqState:
> serverClassName:    'thredds.server.opendap.NcDODSServlet'
> dataSet:            'NWAtlanticDec_1km'
> requestSuffix:      'ascii'
> CE:                 'dsp_band_1[1000:1200][1000:1010][1000:1010]'
> compressOK:          true
> InitParameters:
> DebugOn: ''
> maxNetcdfFilesCached: '10'
> 
> java.io.IOException:
> http://satdat1.gso.uri.edu/opendap/Pathfinder/Northwest_Atlantic/1km/declouded/1986/3/k86079070858.hdf
> HTTP/1.1 403 Forbidden
> at
> ucar.unidata.io.http.HTTPRandomAccessFile3.doConnect(HTTPRandomAccessFile3.java:114)
> at
> ucar.unidata.io.http.HTTPRandomAccessFile3.<init>(HTTPRandomAccessFile3.java:70)
> at
> ucar.unidata.io.http.HTTPRandomAccessFile3.<init>(HTTPRandomAccessFile3.java:53)
> ..................................
> 
> Do you get a sense of where the problem might be that is causing larger
> data requests to fail with these THREDDS aggregated data sets?  Or do
> you have suggestions on where I could look to further diagnose the
> problem?  Appreciate your help once again.  Thanks.
> 
> Carl Wolfteich
> URI-GSO
> 
> 
> 
> 
> 
> 
> 


Ticket Details
===================
Ticket ID: IUW-128695
Department: Support THREDDS
Priority: Urgent
Status: Open


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