There is a number of tools that are as part of a JDK installation. Often, you can rely only on these successfully analyse issues, without the need to resort to (often expensive) 3rd party tools. What is better, these being part of the JDK, they can be used as early as development and testing! Taking and analysing memory dumps, stack traces of java processes running in a particular system, monitoring GC activity.. and more, command line as you would hope when accessing this well-protected machine in a data centre somewhere far. This session will iterate through a number of such tools, discuss purpose and capabilities. All followed with demonstrations of most common usages. Unleash the power of the tools that you already have, today!

1. JDK not so hidden treasures
Andrzej Grzesik

2. andrzej grzesik
@ags313
andrzej@grzesik.it
andrzejgrzesik.info

3. @javazone @ags313
please tweet!

4. questions?
just ask!

5. java

6. $JAVA_HOME/bin

9. tl;dr: log gc
please

10. log gc :-)

11. when things go…

13. does it run?

14. top // htop

16. every known problem becomes completely new
when you add “in Java”
stolen from: @mryapee

17. jps
instead of ps

18. jps
instead of ps

19. jps -lvm
Java ProcesseS LoVe Memory

22. jar

23. jar -tf

25. jinfo

26. demo

28. javac

29. javac
just the compiler

30. javap

33. jmap
instead of pmap

35. and jhat

36. demo

37. stacktraces :)

38. kill -3 <pid>

39. demo

40. caveat ;-)

41. caveat ;-)
prints to STDOUT of the running process

42. jstack

44. caveats
only at safepoints, one thread at a time

47. demo

48. jstat

49. jstat <metric> <options> PID <interval> <count>

50. demo

51. custom options
http://hg.openjdk.java.net/jdk9/jdk9/jdk/file/d49e247dade6/src/jdk.jcmd/share/
classes/sun/tools/jstat/resources/jstat_options

52. jstatd

53. jstatd
exposes your processes

54. jcmd

55. jvisualvm

56. jmxsh
jmxterm
http://wiki.cyclopsgroup.org/jmxterm
http://code.google.com/p/jmxsh/
and more

57. questions?
just shoot!

58. Thank you!