Splunk AppDynamics

value of Max Available under Node/Memory-->Node name-->heap and garbage collection

CommunityUser
Splunk Employee
Splunk Employee

For all our java nodes , I continue to see the value of "Max Available" is less than the -mx set for the jvm

Cant find any documentation on what this  metric stands

Any one knows what this stands for and why it always shows less than the value of -mx. 

Labels (1)
0 Karma

Saradhi_Pothara
Communicator

Hi,

AppDynamics uses JMX provided Java to fetch the max available heap. 

http://stackoverflow.com/questions/11905220/why-does-the-jvm-heap-usage-max-as-reported-by-jmx-chang...

https://docs.oracle.com/javase/7/docs/api/java/lang/management/MemoryUsage.html

It depends on JVMs implementation of the value of HeapMemoryUsage.max attribute on how much this value would be.

You could also validate it against the HeapMemoryUsage.max attribute value in JConsole.

In some JVM implementations, this value is Xmx - PS Survivor Space.MaxAvailable

For Example, Xmx = 12288m and Heap.Max Available is displayed as 11947m.
Check PS Survivor Space.MaxAvailable and it is 341m.

Heap.Max Available = Xmx-PS Survivor Space.MaxAvailable = 12288-341 = 11947m

Please see attached the screenshots.

Regards,
Saradhi

Get Updates on the Splunk Community!

Fueling your curiosity with new Splunk ILT and eLearning courses

At Splunk Education, we’re driven by curiosity—both ours and yours! That’s why we’re committed to delivering ...

Splunk AI Assistant for SPL 1.1.0 | Now Personalized to Your Environment for Greater ...

Splunk AI Assistant for SPL has transformed how users interact with Splunk, making it easier than ever to ...

Unleash Unified Security and Observability with Splunk Cloud Platform

     Now Available on Microsoft AzureOn Demand Now Step boldly into the AI revolution with enhanced security ...