Got my vote for that. Until the PDFBox is perfected to really delve into
this, it will be helpful.

How does the PDFBox stay ahead of the game when Adobe is upgrading and
adding features to the PDF standard? That should be catching up with all of
us sooner or later.

--Jeff

Jeffrey Trimble
System LIbrarian
William F.  Maag Library
Youngstown State University
330.941.2483 (Office)
[email protected]
http://www.maag.ysu.edu
http://digital.maag.ysu.edu



On Apr 8, 2009, at 11:53 AM, Richard Rodgers wrote:

At MIT we came up with a similar approach, which takes some of the
grunt work out of managing the skips. We extended MediaFilter to detect PDFBox (or other) exceptions, then automatically record their handles to a skip list, which is used for any subsequent runs. We'd be glad to give you the code or
just put it into the next 1.5.X release.

Thanks,

Richard R

Quoting Tim Donohue <[email protected]>:

Jeffrey,

I've seen this same issue all to many times to count.  From what I've
noticed it seems that the PDFBox software (which DSpace uses)
occasionally has difficulties with larger PDFs (usually 7MB or larger)
which included OCRed, scanned images.   I've never encountered this
problem with PDFs created directly from digital files (like Word, etc.)...

From what I've seen, occasionally recreating the PDF will resolve the
problem...but, more often than not even that doesn't help. The problem seems to be more of an issue with how PDFBox loads the content into memory.

Locally, I've only come up with two possible solutions:

(1) Increase the memory available to the 'filter-media' script (by
bumping up the -Xmx value in the '[dspace]/bin/dsrun' script).  This
works for some PDFs, but others will continue to have problems (as
PDFBox seems to use up enormous amounts of memory for some PDFs).

(2) Force those problematic PDFs to be skipped over by the
'filter-media' script (by using the -s flag):

To make this easier on myself, I've started maintaining a
"filter-skiplist" file which lists all the handles of the problematic
PDFs (so far we've encountered 35 of them), with a separate handle on
each line.  Then, I pass this "filter-skiplist" file to the cronjob
which runs 'filter-media' like so:

0 2 * * * filter-media -s `less filter-skiplist | tr '\n' ','`

The above script translates all the newlines (\n) to commas (,) in the
'filter-skiplist' file and passes the result to the 'filter-media' -s
(skip) flag.  So, in the end, filter-media receives a comma-separated
list of handles of PDFs which it should no longer process. (Obviously this means any PDFs belonging to items in your 'filter-skiplist' can not
be full text searched in DSpace)

I'm hoping that in the longer term PDFBox will resolve its memory issues
as it comes out of the "incubation" stage under Apache.

If anyone else has potential solutions, I'd love to hear them, as I'm in
a similar situation as Jeffrey.

- Tim


Jeffrey Trimble wrote:
I've run into a funky situation. After using the distributed PDFBOX....and
the associated jars (bouncy castle) the filter media works really,
really well,
until--

We have one pdf that has caused the filter-media to produce a memory dump/ java heap dump. The errors are reports first the IBM flavor of JVM.
We removed
the offending PDF from the database, the filter-media went on it's way
merrily.

Has anyone seen anything like this? I have a copy of the heap dump and
trace.  I can
reproduce it one demand by placing this PDF back into the IR.

If you have seen this, and was able to resolve it, please let me know.
The only thing
I can think of doing is to rescan the PDF file from the original and
seeing if there
is something that resovles itself with the new scan.

Thanks in advance,


Jeffrey Trimble
System LIbrarian
William F.  Maag Library
Youngstown State University
330.941.2483 (Office)
[email protected] <mailto:[email protected]>
http://www.maag.ysu.edu
http://digital.maag.ysu.edu




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http://www.ideals.uiuc.edu/
University of Illinois
[email protected] | (217) 333-4648

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  • [Dspac... Jeffrey Trimble
    • R... Tim Donohue
      • ... Jeffrey Trimble
      • ... Richard Rodgers
        • ... Dorothea Salo
          • ... Tim Donohue
        • ... Jeffrey Trimble
      • ... Thornton, Susan M. (LARC-B702)[RAYTHEON TECHNICAL SERVICES COMPANY]
    • R... Thornton, Susan M. (LARC-B702)[RAYTHEON TECHNICAL SERVICES COMPANY]
    • R... Larry Stone
    • R... Graham Triggs
      • ... Mark Diggory
    • R... Larry Stone
      • ... Mark Diggory

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