Command-line Tool to find Java Heap Size and Memory Used (Linux)?
Is there a Command-line Tool (Linux) to check Heap Size (and Used Memory) of a Java Application?
I have tried through jmap. But it gives info. about internal memory areas like Eden/ PermGen etc., which is not useful to me.
I am looking for something like:
- Max Memory: 1GB
- Min Memory: 256 MB
- Heap Memory: 700 MB
- Used Memory: 460 MB
That's all. I know that I can see this in JConsole etc., but I need a command-line tool (can't enable JMX etc.)
Do you know any such a tool/ command?
Answer
Each Java process has a pid, which you first need to find with the jps command.
Once you have the pid, you can use jstat -gc [insert-pid-here] to find statistics of the behavior of the garbage collected heap.
jstat -gccapacity [insert-pid-here]will present information about memory pool generation and space capabilities.jstat -gcutil [insert-pid-here]will present the utilization of each generation as a percentage of its capacity. Useful to get an at a glance view of usage.
See jstat docs on Oracle's site.