FOP PDF Printing and size limit?

Question

I am using FOP for PDF printing in Apex 3.1.
If I run a simple query:
select object_name, object_type
form obj;
I can print the result to PDF if I limit the rows to 2750 just fine. As soon as I increase it to 2800, the Adobe document has an error and can't be opened.
The OC4J container doesn't receive a memory heap error. I have set the memory values quite high.
It lists in the log lines like:
08/10/16 00:12:01 [INFO] [1]
08/10/16 00:12:52 [INFO] [95]
and then hangs.
No other text appears.
However, on successful completion, the following message appears: Parsing of document complete, stopping renderer
Any thoughts are welcome.

Answer 1

We have the PDF printing working with the increased memory sizes but we noticed something odd that we continue to test. Using the OC4J OEM console, we can see the memory usage as we run the reports. It "seems" like the APACHE FOP keeps taking new chunks of memory for each report without releasing the older ones.
For example, I run report A and it grabs a chunk of memory. I view the PDF then close the window. As I go to another screen and invoke a different report, another chunk of memory is taken without the first one being released. You can watch the memory usage go up and up each time you invoke a report.
We want to do some more testing to see what the test cases are (like if I log off APEX - will the memory then be released?) but I have read other Net postings about memory problems with APACHE FOP.
Just wanted to pass this observation along. Once we have some definitive test cases, I will post them here.