hprof « profile « Java Testing Q&A

1. Java hprof question    stackoverflow.com

What is the difference between using -agentlib:hprof=cpu=times vs -agentlib:hprof=cpu=sample when running a java class? I know that cpu=sample causes the jvm to sample the call stack at regular intervals, but ...

2. Way to convert java.hprof.txt to binary hprof format?    stackoverflow.com

I have a java.hprof.txt file (automatically generated after an OutOfMemoryError) which I would like to convert to the binary hprof format. Is there any easy way to do this?

3. HPjmeter-like graphical tool to view -agentlib:hprof profiling output    stackoverflow.com

What tools are available to view the output of the built-in JVM profiler? For example, I'm starting my JVM with:

-agentlib:hprof=cpu=times,thread=y,cutoff=0,format=a,file=someFile.hprof.txt

4. How to gather profiling information for a Java 1.4 application?    stackoverflow.com

A Java application I support that runs on JRE 1.4.2_12 is hanging near midnight every night. I'd like to try and record as much profiling information as I can to discover ...

5. How do I get multiple hprof dumps in a Java WebStart (JNLP) application?    stackoverflow.com

Working with a Java console application, I can do this:

java -agentlib:hprof=heap=dump,format=b MyClass

6. Can I compare hprof/jmap dumps with VisualVM?    stackoverflow.com

VisualVM crashes when I try to profile our application with it, but if I could load the jmap memory dumps I've done from our application into VisualVM, I could probably get ...

7. Java profiling: java.lang.Object.hashCode takes half of the CPU time but never explictly called    stackoverflow.com

I have been benchmarked my multihreaded program using -agentlib:hprof=cpu=samples and was surprised to find the following line in the results:

rank   self  accum   count trace method
   ...

8. HPROF Could not find agent library cpu on the library path    stackoverflow.com

I am familiar with Oracle's documentation at

http://java.sun.com/developer/technicalArticles/Programming/HPROF.html

Error occurred during initialization of VM Could not find ...

9. Starting the Java HPROF profiler on-the-fly programmatically    stackoverflow.com

I am trying to selectively monitor/profile a Java application when certain runtime conditions are met. I am already able to dump the heap on-the-fly using the HotSpotDiagnosticMXBean, which has ...

10. hprof profiler output doesn't include line numbers regardless of `lineno` value    stackoverflow.com

I'm running

java -cp some:jars:out \
-agentlib:hprof=cpu=times,format=a,file=java.hprof.txt,lineno=y,doe=y com.foo.Benchmark \
< /dev/null

THREAD START (obj=50000150, id = 200002, name="HPROF gc_finish watcher", group="system")
THREAD START (obj=50000151, id = ...

11. Strange results using HPROF Profiler    forums.oracle.com

CPU SAMPLES BEGIN (total = 246) Sun Jun 18 17:56:28 2000 rank self accum count trace method 1 53.66% 53.66% 132 9 java.lang.StringBuilder.expandCapacity 2 17.48% 71.14% 43 13 java.lang.System.arraycopy 3 17.07% 88.21% 42 11 java.lang.System.arraycopy 4 1.63% 89.84% 4 10 java.lang.StringBuilder.toString 5 1.22% 91.06% 3 17 java.lang.StringBuilder.append 6 0.81% 91.87% 2 19 java.lang.StringBuilder.append 7 0.81% 92.68% 2 24 sun.io.CharToByteSingleByte.convert 8 0.81% ...