Great set of articles on Native Memory

I am currently helping a customer with a native memory issue causing OutOfMemory (OOM) exceptions. Most folks are familiar with Java heap memory issues (eg. too much caching eating up live memory or leaking objects), but native memory is also important especially when your application isn't so "pure" (spawning threads, lots of JNI, etc). How do you know if you have a native out of memory? You'll see that you'll get out of memory conditions when the Java heap still has plenty of room left over. In the case I'm working on now, we actually saw the out of memory well before the memory in the heap grew to the maximum size (-Xmx) of the heap. In trying to help the customer out, I found the following articles excellent. The first is a very good overview of native memory and how to diagnose. The second is our app server tech note on things to try in the case you believe you have a native memory issue.

Thanks for the memory - Understanding how the JVM uses native memory on Windows and Linux (Windows/Linux version, AIX version).

Troubleshooting native memory issues

ONLINE SAMPLES

The Samples section of the WAS V8 BETA Information Center is now live!!  http://publib.boulder.ibm.com/infocenter/wasinfo/beta/index.jsp

WebSphere Application Server V8 Beta samples are new and improved and now available for early testing to our WAS V8 Beta customers! Although clients will continue to find key samples installed with the product, additional samples are available online and can be accessed from a new section in the WAS V8 Beta Information Center. Now, samples, documentation, and other resources reside online, under one roof. This will increase availability and collaboration while providing samples in a time-sensitive manner.

Increasing Availability. The sample applications are now on the web, and users can browse individual samples with a direct link or find them using search engines. This is a first for WebSphere Application Server!


Adding Collaboration. As part of the new collaborative information center, users can comment on and rate samples, receive quick feedback, and sign up for updates.

Providing relevant samples in a time-sensitive manner. Online delivery allows samples to be added or updated periodically with regular updates to the information center.

The samples currently available in the Samples section of the WAS V8 Beta Information Center demonstrate the following technologies: Service Component Architecture (SCA), Communications Enabled Applications (CEA), OSGi applications, XML, and Internationalization service.

Look for more to come!