Understanding Increasing the Java Heap Size
When posting files that are five megabytes (MB) or larger to the integration gateway, you should increase the Java heap size in the Simple Post Utility to handle larger file sizes. If the Simple Post Utility does not have enough memory for a task, the system might generate an “Out of Memory” error.
You can increase the heap size to any value that you want, as long as your machine has the random access memory (RAM) to support the value that you choose.
The steps to increase the JVM heap size depend on the web server.