Learning Dtrace

Presentation at play.node() 2012

Transcript

1. Learning Dtrace 2012.11.20 Outsider at
2. DTrace is a comprehensive dynamic tracing framework created by Sun Microsystems for troubleshooting kernel and application problems on production systems in real time. http://dtrace.org/blogs/about/dtracepony/
3. DTrace is a comprehensive dynamic tracing framework created by Sun Microsystems for troubleshooting kernel and application problems on production systems in real time. http://dtrace.org/blogs/about/dtracepony/
4. DTrace is a comprehensive dynamic tracing framework created by Sun Microsystems for troubleshooting kernel and application problems on production systems in real time. http://dtrace.org/blogs/about/dtracepony/
5. DTrace is a comprehensive dynamic tracing framework created by Sun Microsystems for troubleshooting kernel and application problems on production systems in real time. http://dtrace.org/blogs/about/dtracepony/
6. DTrace is a comprehensive dynamic tracing framework created by Sun Microsystems for troubleshooting kernel and application problems on production systems in real time. http://dtrace.org/blogs/about/dtracepony/
7. http://www.flickr.com/photos/ghost_of_kuji/370072145 Bryan Cantrill Mike Shapiro Adam Leventhal
8. Originally developed for 2003
9. Open-sourced in 2005 http://www.flickr.com/photos/tinou/171803338
10. http://www.flickr.com/photos/epu/4299657320 Ported to Unix-like systems
11. MIT Technology Review 2005 “Innovators Under 35” http://www2.technologyreview.com/tr35/profile.aspx?trid=91
12. Technology Innovation Awards 2006 Gold Winner http://www.dowjones.com/innovation/ei_winners_2006.html
13. STUG award 2008 https://www.usenix.org/about/stug
14. Dive into Dtrace
16. ௏٘о प೯غח ૑੼ ز੸ਵ۽ ࢤࢿ ೐۽؋࣌ীࢲ ࢎਊоמ Probe
17. Probe List: sudo dtrace -l
18. Probe੄ ղࠗ ID
19. Probeܳ ઁҕೞח Ҕ (ex: syscall, profile)
20. Unix ݽٕ੉ա Probe੄ য೒ܻா੉࣌ ۄ੉࠳۞ܻ੄ ੉ܴ
21. Probeо ઓ੤ೞח ೣࣻ੄ ੉ܴ
22. Probe੄ ੉ܴ
23. sudo dtrace -l -n PROBE੉ܴ
24. sudo dtrace -l -f FUNCTION
25. sudo dtrace -l -P PROVIDER
26. sudo dtrace -l -m MODULE
27. DScript D Programming Language
28. .d ഛ੢੗ ஹ౵ੌ೧ࢲ ழօۨ߰ীࢲ प೯ উ੹ࢿਸ ਤೠ ਬബࢿ Ѩࢎ ೐۽؋࣌ীࢲ উ੹ೞѱ प೯ Features
29. DScript Kernel User DProgram Output Dtrace
30. probe-description /optional predicate/ { action statements; } 01 02 03 04 05
31. probe-description /optional predicate/ { action statements; } 01 02 03 04 05 provider:module:function:name (ex: syscall:::entry)
32. probe-description /optional predicate/ { action statements; } 01 02 03 04 05 दझమ੄ ࢚కܳ ࣻ૘ೞח ݺ۸ޙ
33. probe-description /optional predicate/ { action statements; } 01 02 03 04 05 0੉ ইפѢա trueݶ action ࣻ೯
34. begin-end.d BEGIN { trace("begin the beguine"); exit(0); } END { trace("that's all..."); } 01 02 03 04 05 06 07 08 09
35. begin-end.d BEGIN { trace("begin the beguine"); exit(0); } END { trace("that's all..."); } 01 02 03 04 05 06 07 08 09 sudo dtrace -s begin-end.d
36. timer.d profile:::tick-5sec { trace("5sec timer"); } profile:::tick-800msec { trace("800msec timer"); } 01 02 03 04 05 06 07 08
37. beer.d int bottles; BEGIN { bottles = 5; } profile:::tick-1sec /bottles >= 0/ { printf("%d bottles on the wall\n", bottles); printf("%d bottles.\n", bottles); printf("take one down, pass it around\n"); printf("%d bottles on the wall\n\n", bottles); bottles--; } profile:::tick-1sec /bottles < 0/ { exit(0); } END { printf("that's all..."); } 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17
38. no if-else no loop ?: operator is exist No Flow Control
39. process.d proc:::exec-success { printf("%s", execname); } 01 02 03 04
40. @: aggregation’s prefix name: aggregation’s name key: D expression list (comma-separated) aggfunc: aggregation function Aggregate @name[key] = aggfunc(args)
41. count() : ഐ୹പࣻ sum(expr) : ಴അध੄ ੹୓ ч avg(expr) : ಴അध੄ ಣӐ min(expr) : ಴അध ઺ о੢ ੘਷ ч max(expr) : ಴അध ઺ о੢ ௾ ч quantize(expr) : 2ઁғ੄ ࠼ب࠙ನ lquantize(expr,lower-bound, upper- bound, step-value) : ࢶഋ ࠼ب࠙ನ Aggregate Function
42. aggr-count.d syscall::read:entry { @counts[execname] = count(); } profile:::tick-5s { exit(0); } 01 02 03 04 05 06 07 08
43. aggr-quant.d syscall::read:entry { self->ts = timestamp; } syscall::read:return /self->ts/ { delta = timestamp - self->ts; @quanttime[execname] = quantize(delta); } profile:::tick-5s { exit(0); } 01 02 03 04 05 06 07 08 09 10 11 12 13 14
44. Dtrace with Node.js
45. http://www.flickr.com/photos/abandonedhero/3404826467 OS Requirements -Dtrace -ustack helper
46. USDT User-Level Statically Defined Tracing landed in node v0.6.7
47. http://www.flickr.com/photos/jepoirrier/2043728206 Full features work on OpenSolaris
48. Mac OS Dtrace ustack helper
49. Linux Dtrace ustack helper
50. Windows Dtrace ustack helper
51. http://www.flickr.com/photos/vectorlyme/206472613 node.js is compiled with --with-dtrace
52. “SunOSীࢲ ഝࢿചغ૑݅ ׮ܲ दझమীࢶ ز੘ೞ૑ ঋח׮”
53. Dtrace with node.js on SmartOS of Joyent Demo
54. server.js var http = require('http'); http.createServer(function(req, res) { res.writeHead(200, { 'Content-Type': 'text/plain' }); res.end('Hello World\n'); }).listen(8124); console.log('Server running!'); 01 02 03 04 05 06 07 08 09
55. http-server.d BEGIN { printf("%7s %2s %5s %20s (%5s) %8s %s (%s)\n", "WHO", "FD", "RPORT", "REMOTE", "BUFFR", "METHOD", "URL", "FWDFOR"); } node*:::http-server-request { printf("+SERVER %2d %5d %20s (%5d) %8s %s (%s)\n", args[1]->fd, args[1]->remotePort, args[1]->remoteAddress, args[1]->bufferSize, args[0]->method, args[0]->url, args[0]->forwardedFor); } node*:::http-server-response { printf("-SERVER %2d %5d %20s (%5d)\n", args[0]->fd, args[0]->remotePort, args[0]->remoteAddress, args[0]->bufferSize); } 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21
56. request-count.d http-server-request { @[args[0]->url]=count() } 01 02 03 04
57. loop.js new Error().stack; function main() { func1(); } function func1() { func2(); } function func2() { (function () { for (;;); })(); } main(); 01 02 03 04 05 06 07 08 09 10 11
58. profile.d profile-97 /execname == "node" && arg1/ { @[jstack(150, 8000)] = count(); } tick-10sec { exit(0); } 01 02 03 04 05 06 07 08 09
59. FlameGraph stack trace visualizer
60. http://dtrace.org/blogs/brendan/files/2011/12/mysql-flame.png
61. node-stackvis $ npm install -g stackvis
62. $ sudo dtrace -s DSCRIPT > INPUT $ stackvis dtrace flamegraph-svg < INPUT > OUTPUT Make FrameGraph
63. Alternative on non-OpenSolarises
64. node-dtrace-provider https://github.com/chrisa/node-dtrace-provider $ npm install dtrace-provider
65. var d = require('dtrace-provider'); var dtp = d.createDTraceProvider('nodeapp'); var p1 = dtp.addProbe('probe1', 'int', 'int'); var p2 = dtp.addProbe('probe2', 'char *'); dtp.enable(); 01 02 03 04 05
66. dtp.fire("probe1", function(p) { return [1, 2]; }); dtp.fire("probe2", function(p) { return ["hello, dtrace via provider", "foo"]; }); 01 02 03 04 05 06
67. data type : int, char maximum argument : 32 Limitations
68. interval.js function interval(msg) { console.log(msg); } setInterval(function() { interval('Hello Dtrace'); }, 1000); 01 02 03 04 05 06 07
69. interval.js interval.js var d = require('dtrace-provider'); var dtp = d.createDTraceProvider('nodeapp'); var p2 = dtp.addProbe('echo', 'char *'); function interval(msg) { dtp.fire('echo', function () { return [msg]; }); console.log(msg); } setInterval(function() { interval('Hello Dtrace'); }, 1000); dtp.enable(); 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15
70. interval.d nodeapp*:::echo { trace(copyinstr(arg0)); } 01 02 03 04
71. Thank you~ http://blog.outsider.ne.kr outsideris@gmail.com @outsideris