Performance Monitoring for the

New Front End

By Emily Nakashima, @eanakashima& Rachel Myers, @rachelmyers

bit.ly/ostrichandyak

Aka: Monitoring Single-Page App

Performance

Aka: SayGoodbye tothe Ostrich.

Aka: SayGoodbye tothe Ostrich.

The Agenda

I. Why Performance?

II. Burying our Head in the Sand

III.Epic Performance Monitoring Yak Shave

IV.The Future

I. Why Performance?

bit.ly/ostrichandyak

Most Performance is in the Front End

Back end Front end

Slow Pages Hurt

Slow Pages Hurt

• Bing: ⬆2s = ⬇4.3% revenue/user

Slow Pages Hurt

• Bing: ⬆2s = ⬇4.3% revenue/user

• Google: ⬆400ms = ⬇.59% searches/user

Slow Pages Hurt

• Bing: ⬆2s = ⬇4.3% revenue/user

• Google: ⬆400ms = ⬇.59% searches/user

• Yahoo: ⬆400ms = ⬇5-9% traffic

Fast Pages Help

Fast Pages Help

• Mozilla:

Fast Pages Help

• Mozilla:

• ⬇2.2s = ⬆15.4% Firefox downloads (+60M)

Fast Pages Help

• Mozilla:

• ⬇2.2s = ⬆15.4% Firefox downloads (+60M)

• Shopzilla:

Fast Pages Help

• Mozilla:

• ⬇2.2s = ⬆15.4% Firefox downloads (+60M)

• Shopzilla:

• conversion ⬆ 7 - 12%

Fast Pages Help

• Mozilla:

• ⬇2.2s = ⬆15.4% Firefox downloads (+60M)

• Shopzilla:

• conversion ⬆ 7 - 12%

• 2x sessions from Search Engine Marketing

Cumulative and Lasting Effects

Cumulative and Lasting Effects

• eBay:

Cumulative and Lasting Effects

• eBay:

• Beginning of experiment: ⬇.44% searches

Cumulative and Lasting Effects

• eBay:

• Beginning of experiment: ⬇.44% searches

• End of experiment:⬇.76% searches

Cumulative and Lasting Effects

• eBay:

• Beginning of experiment: ⬇.44% searches

• End of experiment:⬇.76% searches

• After correction: ⬇.21% searches

Cumulative and Lasting Effects

• eBay:

• Beginning of experiment: ⬇.44% searches

• End of experiment:⬇.76% searches

• After correction: ⬇.21% searches

• Strangeloop:

Cumulative and Lasting Effects

• eBay:

• Beginning of experiment: ⬇.44% searches

• End of experiment:⬇.76% searches

• After correction: ⬇.21% searches

• Strangeloop:

• Took 6 weeks for experiment group visits to recover

Why Performance: The bottom line.

II. Burying our Head in the Sand.

dinosaurs partying with cake and a new relic dashboard!

dinosaurs partying with cake and a new relic dashboard!

12 bijillion

Backbone: the Ostrich Killer

Screenshot of tablet site

Backbone: the Ostrich Killer

Screenshot of tablet site

dinosaurs partying with cake and a new relic dashboard!

dinosaurs partying with cake and a new relic dashboard!

A Diagnostic Slide

• Do you load content with ajax?

• Do you <3 any of these buzzwords?

Ember / Backbone / Angular / whatever-mvc

Turbolinks in Rails4

pjax/hijax

pushState

III. Epic Performance MonitoringYak Shave

Our old tools

• YSlow / PageSpeed Insights

• New Relic

• LogNormal

• WebPageTest

YSlow / PageSpeed

New Relic

New Relic

LogNormal

LogNormal

LogNormal

WebPageTest

WebPageTest

WebPageTest

Nope.

New things to track

• Feature load

• “Page” load

• Unresponsiveness (jank)

New things to track

• { featureName: loadTime }

• { pageName: loadTime }

• [ timestamp, timestamp, timestamp... ]

Surprise tools to the rescue.

• Google Analytics

• Circonus

Google Analytics

Google Analytics

Google Analytics

Google Analytics

The code to add tracking can be fairly straightforward:

_gaq.push([‘_trackTiming’, category, variable, time, opt_label, opt_sample]);

Circonus

Circonus

All together

Feature load

Feature loadTrackTiming = function(category, feature) {  this.category = category;  this.feature = feature;  this.startTime = new Date().getTime();  this.endTime = null;  return this;};

TrackTiming.prototype.startTime = new Date().getTime(); // shared startTime

TrackTiming.prototype.setEnd = function() {  this.endTime = new Date().getTime();  return this;};

Feature loadTrackTiming.prototype.sendFeatureTiming = function() { var time = this.endTime - this.startTime; var twoMinutes = 1000 * 60 * 2; if (time < twoMinutes && time > 0) { window._gaq.push(['_trackTiming', this.category, this.feature, time]); } return this;};

var tt = new TrackTiming(); // init$(‘#myImg’).on('load', function() { tt.setEndTime().sendFeatureTiming();});

“Page” load

“Page” load

• Composed of many features.

• “Page” is loaded is called when sendFeatureTiming has been called for each feature.

“Page” loadTrackTiming.prototype.sendPageTiming = function(pageName) { var time = this.endTime - this.startTime;

window._gaq.push(['_trackTiming', 'custom_timings', pageName, time]);};

// ... set up feature tracking here ...

$.when(trackTiming1, trackTiming2).done( function() { tt.sendPageTiming(); }); // resolves when both timings are done

Unresponsiveness

Unresponsiveness

Unresponsiveness

• Hardest to manage observer effects.

• Strategy: look for moments when the browser isn’t free to take orders.

• Use setTimeout to set timestamps, and see how far apart they fall.

Unresponsivenessvar measurements = [];var now = new Date();

var checkTime = function(measurements) { var newNow = new Date(); measurements.push(newNow - now); now = newNow; setTimeout(checkTime,300);};

// collects an array of times:// measurements = [357,300,300,424,404,300]

IV. The Future

Recap: newthings to track

• Feature load

• “Page” load

• Unresponsiveness (jank)

Feature load

“Page” load// We modified our backbone app to always// call beforeRoute & afterRoute callbacks,// a low-config way to tracking loading.

var beforeRoute = function() { tt.resetPageTiming();};

var afterRoute = function() {var currentPage = window.location;tt.sendPageTiming(currentPage);

};

Unresponsiveness

Thanks!

@eanakashima & @rachelmyersbit.ly/ostrichandyak