Redhat Linux JVM quest
 

Hi All,

Can you please share any weblink which helps me in understanding that what all are the recommended settings for SUN JDK with repect to different redhat kernel version

Actually i am facing frequent Out of memory exception running on linux 64 bit jvm, so just want to understand that is there any in particular recommendation/suggestion linux has for the 64 bit sun jdk.


Thanks in advance for the help

I'm not quite sure how you are trying to relate the JVM settings to a particular RedHat kernel version.

But the amount of memory needed can depend very much on the memory needed by the program the JVM is running.

Have you looked at the options to set memory limits on the JVM, such as the options beginning with the phrase -Xm ???

Often there can be manual pages that get installed with the JVM. So a command such as:

will likely show you the options you can supply to the JVM.

sun no longer exists, there IS NO "sun" jdk
there IS the oracle java and the open source "OpenJDK"

almost every OS has moved to the OpenJDK after oracle wanted to close source java


as to memory problems ???
without knowing even the VERY basic information there is NO way we can even think of helping

we do NOT know what operating system this is other than " some" type of RHEL
red hat what???
4 ,5 or 6

you say 64 bit
BUT what VERSION of java is installed ????
and is it 32 bit or 64 bit?

and what is the HARDWARE ?
dose this box have less that 512 meg ram ?
or
more than 8 Gig's of ram ?

Thanks guys for respOnding

I m having Rhel 6 , having 30Gb ram, having oracle jdk 1.6 update 24 (64 bit).

Actually i m using jconsole to monitor the process memory..& for that process
I have set xmx1024m but after after setting that in jconsole
I m seeing the maxium memory as 2gb.. Why is that can u guys please help me in understand that

---- jconsole displays following for heap usage ---
Used memory@
Committed memory@
Maxium memory@ i did nt understand how this value varies in rhel 6, having 64 bit jvm

OK vicky007aggrwal,

So now we know you're not using OpenJDK, IBM's Java SDK for Linux, etc., you're using Sun's JDK, and part of your concern seems to come from interpreting JConsole output.

In what you've posted, it may be that my browser is not doing a good job of showing me the page, but after the line containing the phrase "jconsole displays following for heap usage", I'm seeing three lines which each include the word "memory" followed immediately by an "at" sign @ rather then a numeric value. So it's not clear to me where JConsole is displaying the 2gb.

In general I can speculate that maybe some of the confusion might be that there can be a difference between things such as the maximum amount of memory used by the JVM, and the maximum amount of memory allocated to objects created by the running Java application program.