Memory not released after creating PDF from report template

I have had our production server lock up a few time recently, and from the logs the issue is that it is out of JVM memory.  I tried increasing the memory from 1024 MB to 1536 MB, but it has not helped. Further investigation has shown that when producing large PDF files (report templates) including multiple images, the memory usage for the JVM on the server goes up from its normal level of about 400MB to 1500+ MB and does not seem to be released after the report generation operation has been completed.  Has anyone else seen this? I have recently upgraded a few app store modules ready for v7 when it is released.  These include: Community Commons from 5.5 to 6.1 Deeplink module to 5.1 AppCloudServices to 1.4.0 DatabaseReplication module to 4.9 The only one of these that has jars that might affect PDF generation is CommunityCommons, so I rolled that back to 5.5 (removing the updated jars), but the issue remains.  Does anyone have an further suggestions?  Thanks Update: I think this issue was caused by the size of image files in the PDF, and the time taken for garbage collection to clean up afterwards.  I have addressed this by increasing the size of the JVM heap, and adding a java action to automatically resize uploaded images
1 answers

Can you analyse this with visualvm locally?