如何使用Xmx命令？ （JVM堆内存）

Question

I'm new in the Oracle world and I'm working with Oracle Identity Analytics (OIA). In the test environment everything is ok, but in production environment i'm getting an "java.lang.OutOfMemoryError", so when I checked the Xmx and Xms I saw that I had Xmx:512m and Xms:512m, that's why I'm trying to modify the Xmx value.

I want to modify the Xmx and Xms values so I wrote the following line in my PuTTY:

$ java -Xmx1024m

But the PuTTY shows me the following:

Usage: java [-options] class [args...] (to execute a class) or
java [-options] -jar jarfile [args...] (to execute a jar file)

where options include:...

Seems like I'm forgetting something after "Xmx1024m", but what? Well, now I know I'm forgetting Jar file, Class or App name but I have no idea how to get any of those things. I tried putting "$AdminServer" after "Xmx1024m" but it didn't work.

My Java version is 1.6.0_45 Oracle JRockit build R28 and the Operative Systems is Linux Server 6.5.

Regards!

Answer 1

You have to pass filepath to execute. Of course, you can run

java -Xmx1024m

but Java doesn't know what file should be executed

Answer 2

You will have to pass the program-name/filename/jar-name,whatever it is,with path for which you want to set/reset the java heap size.

eg

•  java -Xms1024M -Xmx2048M -jar xi.jar 

•  java -Xmx64m ${PROGRAM_NAME} 

Hope this helps you.Or to help you better,could you please tell us what exactly is your scenario?