Node.js Interactive North America 2016: Tracing and instrumentation in Node.js

This talk is a head first dive into the next-gen core tracing API’s being developed under the Node.js Tracing Working Group. We’ll learn about the upcoming AsyncWrap API and how this can be used to build your own high level instrumentation logic in production.

Transcript

1. Thomas Watson @wa7son github.com/watson
2. Who is this guy anyway? • Thomas Watson • Open Source developer at github.com/watson • Node.js Lead at Opbeat • Member of the Diagnostics Working Group under the Node.js Foundation • Tweets as @wa7son @wa7son
3. Tracing in Node.js Instrumentation and @wa7son
4. HTTP Request lifetime Traces Transaction Incoming Request Response @wa7son
5. HTTP Request lifetime BOOM! Traces Transaction Incoming Request Response @wa7son
6. nodejsreactions.tumblr.com The Event Loop @wa7son
7. The Event Loop Node.js process Processing an HTTP request @wa7son
8. The Event Loop Node.js process Synchronous code @wa7son
9. The Event Loop Node.js process @wa7son Another HTTP request
10. @wa7son
11. Request Lifecycle global.currentRequest == Req #1 @wa7son
12. @wa7son global.currentRequest == Req #1 Request Lifecycle global.currentRequest == Req #2
13. @wa7son global.currentRequest == Req #1 Request Lifecycle global.currentRequest == Req #2
14. @wa7son global.currentRequest == Req #1 Request Lifecycle global.currentRequest == Req #2
15. @wa7son global.currentRequest == Req #1 Request Lifecycle global.currentRequest == Req #2
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19. Patch the world • Patch every async operation in core • timers • Promise (native) • (process.nextTick) • libuv • Patch certain 3rd party modules @wa7son
20. AsyncHooks https://github.com/nodejs/diagnostics @wa7son
21. AsyncHooks https://github.com/nodejs/diagnostics @wa7son
22. @wa7son
23. user: before async_wrap: init user: after async_wrap: pre user: done async_wrap: post async_wrap: destroy @wa7son
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25. TypeError: console.log is not a function @wa7son
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28. user: before async_wrap: init user: after async_wrap: pre user: done async_wrap: post async_wrap: destroy @wa7son
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30. > var asyncWrap = process.binding('async_wrap') undefined > asyncWrap.Providers { NONE: 0, CRYPTO: 1, FSEVENTWRAP: 2, FSREQWRAP: 3, GETADDRINFOREQWRAP: 4, GETNAMEINFOREQWRAP: 5, HTTPPARSER: 6, JSSTREAM: 7, PIPEWRAP: 8, PIPECONNECTWRAP: 9, PROCESSWRAP: 10, QUERYWRAP: 11, SHUTDOWNWRAP: 12, SIGNALWRAP: 13, STATWATCHER: 14, TCPWRAP: 15, TCPCONNECTWRAP: 16, TIMERWRAP: 17, TLSWRAP: 18, TTYWRAP: 19, UDPWRAP: 20, UDPSENDWRAP: 21, WRITEWRAP: 22, ZLIB: 23 } @wa7son
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32. Handle Objects Node Core Userland libuv V8 JavaScript C / C++ @wa7son
33. Handle Objects net.connect @wa7son
34. Handle Objects net.connect Handle objects @wa7son
35. Handle Objects net.connect req === this socket === this @wa7son
36. Timers @wa7son
37. Timers user: before #1 async_wrap: init user: after #1 user: before #2 user: after #2 @wa7son
38. Timers user: before #1 async_wrap: init user: after #1 user: before #2 user: after #2 async_wrap: pre user: done #1 user: done #2 async_wrap: post async_wrap: destroy @wa7son
39. @wa7son Real World Example
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49. AsyncHooks Gotchas • Handle creation time • console.log • (process.nextTick) • Timers • Promises • Multiple AsyncHooks @wa7son
50. New AsyncHooks API https://github.com/nodejs/node-eps/pull/18 @wa7son
51. @wa7son I/O in user-land
52. Embedder API • Native API - for native modules • JavaScript API - for JavaScript modules @wa7son
53. JavaScript Embedder API async_hooks.newUid() async_hooks.emitInit(id, handle, type[, triggerId]) async_hooks.emitBefore(id) async_hooks.emitAfter(id) async_hooks.emitDestroy(id) @wa7son
54. ES Modules @wa7son
55. https://github.com/nodejs/node-eps/pull/18 @wa7son
56. https://github.com/nodejs/diagnostics @wa7son
57. https://github.com/nodejs/diagnostics/tree/master/tracing/AsyncWrap @wa7son
58. https://github.com/nodejs/diagnostics/issues/29 @wa7son
59. Thank you @wa7son github.com/watson