Processing large batches of PDF documents

Q: Currently we are integrating SDK to our software solution.
Generally it works fine.

When processing a large bunch of PDF Single Pages, which are simply
converted to JPG-Images using your component, we sometimes get the
following Exception:

pdftron.Common.PDFNetException: Unknown exception.
bei pdftron.PDF.PDFDraw.Export(Page page, String filename, String
format, Obj encoder_hints)

We are doing batch processing and the jobs are hold in a queue, which
starts a new job, when the previous is done. I have no idea, when and
why this exception comes up. Sometimes 5000 pages are processed
without problems, then, after filling the queue again with X jobs for
Example, the Exception is thrown after 800 Image Creations. Also to
mention that in case of the thrown Exception, all other upcoming
remaining jobs in queue will lead to this exception too.

A: It sounds like you are not releasing certain resources on time. Are
you closing documents when they are no longer in use (doc.Close())? Do
you dispose PDFDraw (or ElementBuilder/ElementWriter/PDFView/
TextExtractor) when it is no longer in use? The sample code you use
for coversion (or event better a small sample project) would help us
to quickly identify the issue.