Fop error: java.lang.OutOfMemoryError error when generating a PDF

["Mark Peters" <flickrmeister@gmail.com>]

I'm in the process of converting my company's install guide to DocBook. Because our product can be installed on a wide variety of server software environments, I'm using profiling to indicate the document sections that apply to a particular operating system or database management system, for example. In all, there are 30 variations of the guide produced from the same set of DocBook XML files, all of which average 150-200 pages.

 

Currently, I'm using batch files (in Windows) to:

1. Generate the database file (for cross-references) using xslproc
2. Generate an XML document based on my profiling criteria using xslproc
3. Generate the XSL-FO file using xslproc
4. Generate the PDF using Fop.

These steps successfully produce all but half a dozen of the different versions of the document. The rest of the versions fail during fourth step, when Fop is converting the XSL-Fo file to PDF. Fop quits with the following error:

 

Exception in thread "main" java.lang.OutOfMemoryError <<no stack trace available>>

 

 

My log file contains a number of other errors; however, none of these errors in and of themselves are fatal. Fop also displays these errors while converting the other versions of the doc -- the ones that are completed successfully.

 

For example:

 

[ERROR] JAI support was not installed <read: not present at build time>. Trying to use Jimi instead
Error creating background image: Error creating FopImage object < http://docbook.sourceforge.net/release/images/draft.png> : Jimi image library not available
 

[ERROR] Error in content-height property value 'scale-to-fit': org.apache.fop.fo.expr.PropertyException: No conversion defined
 

[INFO] area contents overflows area in line
 

[ERROR] Unknown enumerated value for property 'span': inherit
[ERROR] Error in span property value 'inherit': org.apaache.fop.fo.expr.PropertyException: No conversion defined

 

 

 

What I've tried so far:

* Added the -Xmx2048m switch to my fop.bat file. (I'm using a quad Xeon box with 4 GBs of RAM.)

* Watched my processor and memory usage. The Java.exe file never exceeds 70 MB of memory usage. My processor performance averages less than 30% usage, with occasional brief spikes -- but none when the OutOfMemoryError messages occur.

* Added breaks in some of my longer text lines (such as long URLs) to try to eliminate the "area contents overflows area in line" messages -- without much success.

 

 

Does anyone have any suggestions for isolating the cause of the OutOfMemoryError messages?  I seem to be giving Java.exe plenty of memory to work with. Fop does not seem to be failing at any one particular location in the process (based on the [INFO] [<page number>] messages in the log).

 

Thanks!

 

Mark Peters