Best way to measure memory usage in a Java program?

Question

I am currently using VisualVM , but the problem I am facing is that I cannot save the graphics that it creates. I need to provide some data on memory usage and runtime, although runtime is easy to get with System.nanoTime() . I also tried the NetBeans profiler , but this is not what I want, since I am not looking for specific parts that would slow it down or something else, so that would be redundant. The biggest problem is that it takes too much time to process. Also does not allow me to easily capture / migrate data like VisualVM, at least as far as I can tell.

Ideally, the best way to do this would be to call the method, because then I can get the information much easier, but something like VisualVM, which actually allows me to save the graph, is fine. Performance with VisualVM is also good compared to the NetBeans profiler, although I believe that since I did not use its profiler.

I am currently using Ubuntu, but Windows 7 is fine. I would rather have a program that specializes in this, though, since the information received from programs that do not do this will most likely include the JVM and other things that are best left out.

Well, apparently, you can save snapshots of the current session and enlarge the window in VisualVM so you can make the charts bigger, take a picture and cut them ... But such a hack. Best suggestions are welcome.

Answer 1

 Runtime.getRuntime().freeMemory(); Runtime.getRuntime().totalMemory(); 

Answer 2

Take a look at the Runtime class. It has freeMemory, maxMemory and totalMemory. It is probably close enough for your purposes.

Answer 3

You can choose an elegant method of measuring memory, and not hack the image. JConsole is known to control applications using JMX ; it provides a software API. I think this is what you need.

See: Using JConsole to Monitor Applications

Answer 4

Try JProfiler . Although it is not free, you can try the trial version first.

Answer 5

The HPjmeter console is free. Start the Java process with -Xloggc:<file> and open <file> with it. You can not only save your sessions, but also compare the results. Other options to include in your command line:

 -XX:+PrintGCTimeStamps -XX:+PrintGCDetails