[Iplant-api-dev] What are the best practices for getting 4-8GB java JVMs for testing?

[Damian Gessler]

Lonestar appears to be running tight today.

Per Rion's response yesterday on allocating a JVM, this worked yesterday:

 > login1$ java -Xmx5099m -version
 > java version "1.7.0_45"
 > Java(TM) SE Runtime Environment (build 1.7.0_45-b18)
 > Java HotSpot(TM) 64-Bit Server VM (build 24.45-b08, mixed mode)

but today it fails:

	login2$ hostname
	login2.ls4.tacc.utexas.edu
	login2$ module load java64
	login2$ java -Xmx5099m -version
	Error occurred during initialization of VM
	Could not reserve enough space for object heap
	Error: Could not create the Java Virtual Machine.
	Error: A fatal exception has occurred. Program will exit.

Some experimenting (even w/ 32-bit jdk32 and 4GB limit) shows spotty 
behavior, with sometimes even quite small allocs failing.

A snapshot of top(1) on lonestar shows:

	...
Mem:  24675392k total, 24632400k used,    42992k free,   221316k buffers
Swap:        0k total,        0k used,        0k free, 16030668k cached
	...

which is way tight and is perhaps ?? why mem alloc is failing.

But when I log into stampede or longhorn, none of my home files are 
available (must be mounting a different home dir).

Question:

As a best practice, onto which machine should I login so as to get 
reliable 4-8GB java64 mem alloc for fAPI testing applications? (If it is 
stampede or longhorn, I can copy files to home no prob).

Damian.