Why JRVerticalFiller consume almost all my memory?

[igordmitriev7]

Hi there. I noticed that my application is slow. I've decided to analyze GC logs and Heap dump. All of a sudden I got this:

It starts from TaskThread which holds JRVerticalFiller, that one holds JasperPrint, from JasperPrint hand - Collections.synchronizedList(pages), these objects are JRTemplatePrintText.

Here is a gc roots from TaskThread to Object[] (this Object[] in ArrayList)

NOTE: I am using JRGzipVizualizer.

Actually I don't understand why TaskThread is still alive and why so many objects are created.

JRVerticalFiller took 3.6GB of 4GB heap memory.