The Bits Behind JS Bin

The story behind JS Bin, how it came to be, why it moved to Node, the drivers and some of the challenges in running the app.

Transcript

1. The Bits Behind JS Bin Remy Sharp — @rem
2. Hi. Mine: nodemon 5minfork.com Full Frontal Me: @rem remy@leftlogic.com remysharp.com
3. JS Bin?
4. • 415,000 uniques/month (2mil page views) • 30-35 queries per second • 69,000+ registered users • 9.6mil bins in total / 1.5mil "owned" bins • 48 timers & lots of iframes!
5. BACKSTORY
6. Originally a PHP hack • Inspired by XHR insolation issues • Proceeded by ugliness (codedumper.com) • Tipping point: John Resig's http://ejohn.org/apps/learn/ • Approximately 4 hours of dev to live
7. Workshop in Iceland
8. Code Casting I wanted to create
9. jsconf.eu 2009
10. Förbind http://forbind.net
12. Pre-decent require
13. Pre-package knowledge
14. Straight up nutty
15. 2 hours later...
17. Förbind: how it works express socket.io mongodb ejs Tightly coupled collections listening for messages, then firing it on all open connections. Restart and it all breaks...
18. April 2012 & @aron
19. 100% JavaScript
21. Pros of Node for JS Bin • CodeCasting & live reload (across all platforms) • Easy local and dependency free installs • Some code reuse, lots of knowledge reuse.
22. The Spike
23. Thank you Boris Grishenko
24. Author JS Bin XHR save on keypress DB spike.js update event IE8 Chrome xbox iOS Firefox OS etc SSE push The Spike
25. • Client saves on keypress • Server on save triggers "spike update" event with bin passed to event • Spike searches for sessions interested in that bin, and sends the updated panel
26. All authored content is streamable •CodeCasting is easy •LiveReload is easy •Live injection into PhoneGap is easy
27. Good Side Effect • XSS recently fixed using postMessage & run.jsbin.com • IE7 doesn't support postMessage • But IE7 does LiveReload - so IE still works & securely
30. if (res.connection.writable === false) { // remove cached connection } Is the connection open?
31. Testing event source • Sadly no devtools (http://crbug.com/254973) • curl --header "Accept: text/event-stream" <url>
33. No WebSockets? •EventSource is polyfilled only with JS •IE6-9 •Android Browser
35. Local installs • Always possible since day #1 on github • Now via `npm install -g jsbin` • Windows support is (now) pretty solid
36. Database upgrades via npm • Package.json "scripts": { "install": "build/install.js", "preupdate": "build/pre-update.js", "postupdate": "build/post-update.js" }, • Pre-update - saves current version • Post-update - uses semver & checks upgrade/<version>/*.sql
37. Dependency free •USB contains Node binaries for all platforms, code & dependancies •Saves to raw HTML files on USB stick •For teaching in strict tech environment
38. todo •Add update-notifier for prompted updates •Get visibility on local installs •Release to npm frequently
39. Features
42. • Paid/donated • Alternative domain (ie. jsbin.leftlogic.com) • Each dev runs under rem.jsbin.leftlogic.com • Now we can remotely view each other's work ngrok
43. Production
44. scripts.json
45. index template
46. Grunt build generates concat & uglified. Triggered by...
47. .git/hooks/post-merge remy@jsbin:/WWW/jsbin$ git pull remote: Counting objects: 19, done. remote: Compressing objects: 100% (7/7), done. remote: Total 11 (delta 8), reused 7 (delta 4) Unpacking objects: 100% (11/11), done. From git://github.com/remy/jsbin a7bf4f8..f99beff master -> origin/master * [new branch] feature/menu-update -> origin/feature/menu-up Merge made by the 'recursive' strategy. test/loop_detection_test.js | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) rebuild jsbin.js? [Y/n] y building public js Running "concat:dist" (concat) task File "public/js/prod/jsbin-3.4.8.js" created. Running "concat:runner" (concat) task File "public/js/prod/runner-3.4.8.js" created. Running "uglify:dist" (uglify) task Source Map "public/js/prod/jsbin.map.json" created. File "public/js/prod/jsbin-3.4.8.min.js" created. Running "uglify:runner" (uglify) task File "public/js/prod/runner-3.4.8.min.js" created. Done, without errors. restart jsbin? [Y/n] y restarting forever info: Forever restarted processes: data: uid command script forever pid logfile
48. Upstart console log stop on shutdown respawn respawn limit 20 5 post-start script # log that we restarted logger -is -t "$UPSTART_JOB" ">>>>>>>> jsbin restart" # email the last 100 lines from the log tail -100 /var/log/upstart/jsbin.log | mail -s "ALARM: jsbin restart" jsbin@leftlogic.com end script script set -e # make sure you only write out to /var/log/upstart/<task> exec sudo -u www-data PORT=8000 /usr/local/bin/node /WWW/jsbin/ 2>&1 end script https://github.com/jsbin-org/production/blob/master/apps.jsbin.com/etc/init/jsbin.conf
49. •URLs - probably not fixable •Database choice - fixable hard •Database adapter logic - fixable easy •Near total lack of tests - fix in progress Mistakes
50. It's hard •Memory leaks •CPU loops •Easy to get lazy
51. gdb ftw http://remysharp.com/2013/09/11/how-i-fixed-an-anonymous-infinite-loop-in-jsbin/
52. Sustainability: Pro • Dropbox support & live syncing • Bin playback & annotation • Sass, SCSS, smart screenshots... • Branded JS Bin's ala http://emberjs.jsbin.com
53. ⾨