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I realize that similar questions have been asked about this before here on SO, but let me describe exactly what I need to do:
I have a set of tests which run a command line java application and I'd like to add memory profiling to them. One option I see would be to add code (possibly using 3rd party tools/libraries) to my application that would provide a memory snapshot. Another option would be to use a third party tool which manages/instruments my application and the JVM for me (and ideally does not require me to change my code). I'm thinking of something like Valgrind but for Java. Also open source if at all possible.
What I'd really like to do is set up the memory tests so that my memory usage is being monitored at regular intervals, let's say every second, and dumped to a text file. That way I'd be able to see if the memory usage oscillates/increases/decreases over time. I'll also be able to calculate the max and min peaks.
Has anyone here done anything like this?
Thanks in advance.
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Memory-Monitoring Tools Since Java 5, the standard JDK monitoring tool has been JConsole. The Oracle JDK also includes jStat, which enables the monitoring of memory usage and garbage-collector activity from the console, and Java VisualVM (or jvisualvm), which provides rudimentary memory analyzes and a profiler.
Memory profiling enables you to understand the memory allocation and garbage collection behavior of your applications over time. It helps you identify method calls in the context within which most memory was allocated and combine this information with the number of allocated objects.
The most obvious place to start tuning the memory footprint is the Java heap size. If you reduce the Java heap size, you reduce the memory footprint of the Java process by the same amount. You cannot reduce the heap size beyond a point; the heap should be large enough for all objects that are live at the same time.
The short answer is that you use these java command-line parameters to help control the RAM use of application: Use -Xmx to specify the maximum heap size. Use -Xms to specify the initial Java heap size. Use -Xss to set the Java thread stack size.
With something like JProfiler all you need to do is add certain parameters to the JVM. It uses JVMTI.
I think you should be reading up on profilers and exactly what they can do for you. I also suggest reading up on JVMTI.
The JVMTM Tool Interface (JVM TI) is a new native programming interface for use by tools. It provides both a way to inspect the state and to control the execution of applications running in the Java virtual machine (JVM). JVM TI supports the full breadth of tools that need access to JVM state, including but not limited to: profiling, debugging, monitoring, thread analysis, and coverage analysis tools.
Note: JVM TI replaces the Java Virtual Machine Profiler Interface (JVMPI) and the Java Virtual Machine Debug Interface (JVMDI). JVMPI and JVMDI will be removed in the next major release of J2SETM.
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