Here's how to allocate a larger heap from the WebStart bash command line.
Instead of editing the jnlp file, prior to execution; the command line can
be used to do it with the "-J" construct as followed.
Here's what I tried, but wasn't sure it had worked. The -J construct
is suppose to pass the -Xms1g (or 1000m) , etc. to the VM in theory. It's a
24gigabyte server, and I needed the extra headroom in heap to run
a number of Swing-based GUI strategy modules.
#!/bin/bash
# Proper header for a Bash script.
curl
https://platform.dukascopy.com/demo/jforex.jnlp > jforex.jnlp
# allocate a gigabyte min and max for heap
javaws -Xnosplash -J-Xms1g -J-Xmx1g jforex.jnlp
The Java Server version:
java version "1.8.0_51"
Java(TM) SE Runtime Environment (build 1.8.0_51-b16)
Java HotSpot(TM) 64-Bit Server VM (build 25.51-b03, mixed mode)
The JForex platform showed an allocation of about 924m in the heap display
which I'm confident is the 1g allocation, just a bit of rounding error
in the heap widget display on JForex

hyperscalper