Difference between revisions of "Java VM"
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=== Memory === | === Memory === | ||
| − | The most common issue when dealing with memory is that Java expects to have access to all of the memory that is visible on a given machine. This is not true on the | + | The most common issue when dealing with memory is that Java expects to have access to all of the memory that is visible on a given machine. This is not true on the ACENET compute nodes, as your job will only have access to whatever amount of RAM that you have requested. The JVM itself may require anywhere from 1-2 GB of RAM for itself, before any memory allocated for your actual program. So when requesting memory in your submission script, always ensure that you add 1-2GB more than you are setting in the Java command line option "-Xmx". |
Revision as of 13:48, February 20, 2015
- Description
- Java is a programming language and computing platform. We provide JRE & JDK.
- Modulefile
java- Documentation
- Java homepage
- Usage
$ module load java $ java
Notes
There are several known issues with using Java in a multi-user environment with resource limits in place. These notes will describe the most common ones to date.
Memory
The most common issue when dealing with memory is that Java expects to have access to all of the memory that is visible on a given machine. This is not true on the ACENET compute nodes, as your job will only have access to whatever amount of RAM that you have requested. The JVM itself may require anywhere from 1-2 GB of RAM for itself, before any memory allocated for your actual program. So when requesting memory in your submission script, always ensure that you add 1-2GB more than you are setting in the Java command line option "-Xmx".