IBM JDK Archive

How to Analyze verbosegc of IBM JDK


We can use IBM Pattern Modeling and Analysis Tool for this purpose.
Its a very simple and effective tool to analyze gc activity.
It provides many views like graph view, chart view and analysis view.

Details and download link can be found here

Download the software from the link above.

Start the tool using the following command line.

E:\tools\ga412>java -jar ga412.jar

Open the file (xxx_native_stderr.log)  that you want to analze.

Go to Analysis > Graph View All

It will open up the Chart View where you will be able to see the heap usage over time.

From the image below you will notice that the heap usage raches the max at around 13:40.


We need to check the server logs for any Out of Memory errors. Also need to check what the application is doing during that time.
The number of users accessing the application. If these don’t give enough information, we can take heapdumps and analyze it.

Reference :-