[FWTools] GDAL hanging under Windows 2008 Server

[Frank Warmerdam]

Stephen Wealands wrote:
> I'm using GDAL via the SharpMap mapping engine.  It makes use of the 
> csharp wrappers to render imagery (in my case, ECW) to an image control 
> on a web page.  I am currently running it under Windows 2008 Server.
>  
> My problem is that I am finding that the gdal library is intermittently 
> hanging when being requested for imagery.  I have got a log from 
> ProcessMonitor here 
> (http://spreadsheets.google.com/ccc?key=pnbsLIAZM8M_34TfXUVttcA) that 
> shows where it occurs and thought someone here might be able to suggest 
> what could be causing the problem. 
>  
> Rows 1-40 show a successful map creation operation (including display of 
> ECW image).  Row 41 onwards shows what happens when the image is panned 
> and gdal hangs.  Seems to be associated with 'gdalplugins', but I'm not 
> sure what this is.  Row 64 is the line where it crashed.  Row 65 is the 
> start of where I recycled the web app to get it back from hanging. 
>  
> Note that this runs fine much of the time and has never crashed when I 
> am only displaying shapefiles.  However, when displaying raster images 
> as well, this occasionally crashes and therefore gdal must be the 
> involved somehow. 

Stephen,

I have experienced intermittent hangs and crashes with the ecw sdk from
time to time - more often on linux or when having built the ECW SDK myself
from source.  You might want to test with a non-ecw image and see if that
works reliably.  If so, the issue is either the ecw sdk or the GDAL ECW
driver.

However, it is not at all clear how those issues might be fixed.  I advise
converting ecw images to geotiff when problems are encountered.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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