Python, DTrace and you

Learn about how Python and DTrace operate together

Transcript

1. DTrace, Python and you! ! ! Mark Allen! mrallen1@yahoo.com! @bytemeorg! http://byte-me.org! https://github.com/mrallen1!
2. DTrace Basics What is DTrace?!
3. DTrace Basics Dynamic Tracing!
4. DTrace Basics Dude! Srsly?!! Dynamic versus what?!!
5. DTrace Basics Dynamic versus! print "got here!" @profile def do_stuff(self, **kwargs): print "This is fun!" See  h%p://mg.pov.lt/profilehooks/  for  @profile  decorator  
6. DTrace Basics "Observability technology"1! 1  DTrace:  Dynamic  Tracing  in  Oracle  Solaris,  Pren=ce  Hall,  2nd  ed,  2012.  
7. DTrace Basics In a DTrace enabled OS, you get full scope visibility!
8. DTrace Basics Applica=on   Libraries   System   Calls   Kernel  
9. DTrace Basics It's turtles all the way down...! h%p://flic.kr/p/aQDPrZ  
10. DTrace Basics It's like X-Ray vision into your application and operating system.! ! (And it's fun!)! (And it's neckbeardy!1one)!
11. DTrace Basics Examples:! •  Trace socket accepts and debug your web application's "real" code execution pathway! •  Profile why NFS gets super busy at 0430 and a directory tree traversal takes 2 hours instead of 2 minutes.!
12. DTrace Basics DTrace enabled OSes:! •  Solaris 10+! •  OpenSolarisIllumos! •  SmartOS (Joyent)! •  OmniOS (OmniTI)! •  FreeBSD! •  Mac OS X!
13. DTrace Basics What about Linux?!
14. DTrace Basics You're looking for the talk! "SystemTap, python and you"! ! Try down the hall, on the left.! ! ! (Sorry)  
15. DTrace Basics DTrace Terms!
16. DTrace Basics Provider! ! Manages probes in a subsystem!
17. DTrace Basics Provider! ! In our case, this is the python binary itself. ! ! (More on this soon)!
18. DTrace Basics Probes! ! DTrace ! instrumentation or! "observables"!
19. DTrace Basics Consumer! ! A user-mode program! that calls into DTrace!
20. D Language Basics D Language Basics!
21. D Language Basics D Language Overview! •  awk-like! •  Define a probe, optional predicate and optional actions in a braced clause! •  Supports BEGIN and END blocks! •  Local variables (this->foo = 42)! •  Aggregate/associative variables (prefixed with @)! •  One liner support in the form! dtrace -n 'probe /predicate/ {action}'
22. D Language Basics $ cat dtrace-example.d #!/usr/sbin/dtrace -s probe /predicate/ { actions }
23. D Language Basics Example 1!
24. D Language Basics REAL Example 1!
25. D Language Basics $ cat subentry.d #!/usr/sbin/dtrace -qFZs function-entry, function-return { /* arg1 is function name */ trace(copyinstr(arg1)) }
26. D Language Basics $ cat subentry.d #!/usr/sbin/dtrace -qFZs function-entry, function-return { /* arg1 is subroutine name */ trace(copyinstr(arg1)) }
27. D Language Basics $ cat subentry.d #!/usr/sbin/dtrace -qFZs function-entry, function-return { /* arg1 is subroutine name */ trace(copyinstr(arg1)) }
28. D Language Basics REAL Example 2!
29. D Language Basics $ cat subcount.d #!/usr/sbin/dtrace -qZs function-entry { /* Count sub entries by package and sub name * arg0 = source file name * arg1 = function name (def do_something():) */ @[strjoin(strjoin(copyinstr(arg0),"-"),copyinstr(arg1))] = count() } END { /* Give me top 10 highest counts; throw away rest */ trunc(@, 10) }
30. D Language Basics $ cat subcount.d #!/usr/sbin/dtrace -qZs function-entry { /* Count sub entries by package and sub name * arg0 = source file name * arg1 = functiuon name (def do_something():) */ @[strjoin(strjoin(copyinstr(arg0),"-"),copyinstr(arg1))] = count() } END { /* Give me top 10 highest counts; throw away rest */ trunc(@, 10) }
31. D Language Basics $ cat subcount.d #!/usr/sbin/dtrace -qZs function-entry { /* Count sub entries by package and sub name * arg0 = source file name * arg1 = functiuon name (def do_something():) */ @[strjoin(strjoin(copyinstr(arg0),"-"),copyinstr(arg1))] = count() } END { /* Give me top 10 highest counts; throw away rest */ trunc(@, 10) }
32. D Language Basics $ cat subcount.d #!/usr/sbin/dtrace -qZs function-entry { /* Count sub entries by package and sub name * arg0 = source file name * arg1 = functiuon name (def do_something():) */ @[strjoin(strjoin(copyinstr(arg0),"-"),copyinstr(arg1))] = count() } END { /* Give me top 10 highest counts; throw away rest */ trunc(@, 10) }
33. D Language Basics subcount.d  for  pyge%/test/basic_test.py  
34. D Language Basics Common aggregation functions! •  avg! •  count! •  lquantize (linear)! •  quantize (log - power of 2)! •  sum! •  min! •  max!
35. DTrace and Python DTrace and Python!
36. DTrace and Python Build your own with brew brew install python \ --with-dtrace
37. DTrace and Python Build your own with pythonz* pythonz install \ --dtrace 2.7.5 (* apply https://github.com/saghul/pythonz/pull/43)
38. DTrace and Python
39. DTrace and Python function-entry! function-return! line! (FILE, FUNCTION, LINE)
40. DTrace and Python gc-start! (GENERATION) Similar to gc.collect()!
41. DTrace and Python gc-done! (OBJECTS_COLLECTED)
42. DTrace and Python instance-new-start! instance-new-done! instance-delete-start! instance-delete-done! (CLASS_NAME, FILE)
43. DTrace and Python Make your own DTrace probes in Python by using ! ! http://tmetsch.github.io/python-dtrace/! ! Available on PyPI too!
44. Resources DTrace resources: •  http://dtracehol.com/#Intro •  http://dtrace.org/guide/preface.html •  http://dtracebook.com/index.php/ Languages#Python •  http://www.amazon.com/dp/0132091518
45. Thanks! Thank you!!