Thank you – we really appreciate your tracking down the issue.
We tested the Hovmoller plots and animation for GHRSST NCDC AVHRR_OI on our test server, which is running LAS 7.3 and Ferret 6.842. On our test server, instead of getting the error we reported earlier in this
thread, we get a pink stripe on a red background. (see attached) Our public operational server is LAS 7.3 and Ferret 6.72, and has the “remote server unable to deliver data” (as reported earlier).
Then we looked at the NODC LAS server, which is using LAS 7.3, Ferret 6.82. The same hovmoller plot returned a result with the pink stripe, red background, just like our test server. (attachment 2)
This seems to indicate that the older version of Ferret handles the NetCDF library error in a different way (giving an explicit error return) than the more recent Ferret (strange plot returned).
Does this behavior difference corroborate the NetCDF library error assessment?
Would you please outline what the tests were and how the tests accessed our data – ie, using our THREDDS URL link to a single variable and time index, or downloading files via FTP and running the decompressed
files? We are trying to build up a suite of tests to help our diagnostics, and confirm the data integrity in our cache.
We are currently trying to get LAS 8 set up in a test environment – if a solution is found for this issue for LAS 8, we will step up our timeline to switch to LAS 8.
Thank you very much,
From: Ansley Manke [mailto:ansley.b.manke@xxxxxxxx]
Sent: Wednesday, May 01, 2013 11:56 AM
To: Shelton, Kacie E (398C)
Subject: Re: [las_users] LAS Animation error response
Both this issue with animations and your question last week about Hovmuller plots with datasets having long time axes are running into an error in the NetCDF libraries when we try to read strided (decimated) grids of data.
I've tested these kinds of read operations on your datasets with with the various versions of NetCDF, and none of them return a correct result. I have made a report to the authors of the NetCDF library.
I see that your LAS is currently running version 7.3. When we do have a fix for this, it will require an upgrade to your LAS, to the newer LAS Version 8.
On 5/1/2013 10:17 AM, Ansley Manke wrote:
This is very likely the same issue that you wrote about last week. Again, we're asking for a portion of the data, in this case a number of time steps spaced across the time region you have asked for. The first step of making an animation is to get the range
of the data represented, so that the color scale can be the same across all the frames of the animation. Once that's done, we can just read one timestep at a time and make the image.
I'll try to get back to you in the next couple of days.
On 4/30/2013 2:47 PM, Shelton, Kacie E (398C) wrote:
We are having issues with LAS animation, and it nominally appears to be the same or similar error with our datasets that are very large (either volume or time series).
The behavior: we can only request animation for a very small area for only a few days. If an error returns, we need to close the tab, return to the main LAS window, and click on Animation again – basically trial and error to find how
many granules it will animate in one request. 6 granules is the limit for the dataset GHRSST AVHRR_AMSR_OI. The error is returned before the “Stop Downloading” button appears.
Cached data cleared from memory
NetCDF: Malformed or inaccessible DAP DATADDS (OPeNDAP/netCDF Error code -73)
I am attaching an image of the error, and a rtf of the long error report.
Any idea what is going on?