Client-Side Performance Testing

CLIENT-SIDE PERFORMANCE TESTING

Anand Bagmar

Software Quality Evangelist

ABOUT ME

@BagmarAnand

Blog - essenceoftesting

about.me/anand.bagmar

WHAT DO YOU EXPECT FROM THIS WORKSHOP?

Why do we have to think about, or, do

Performance Testing?

https://www.crazyegg.com/blog/speed-up-your-website/

https://www.crazyegg.com/blog/speed-up-your-website/

What is

Performance Testing?

https://en.wikipedia.org/wiki/Software_performance_testing

What is

Performance Engineering?

https://en.wikipedia.org/wiki/Performance_engineering

Techniques to improve Performance

TECHNIQUES TO IMPROVE PERFORMANCE

We need to understand, and optimize

¨ Architecture, and

¨ How content gets delivered to the end-user

CDN – Content Delivery Network

https://en.wikipedia.org/wiki/Content_delivery_network

How does CDN work?

http://www.slideshare.net/gsluthra/harnessing-the-power-of-cdns



By Kanoha - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=7868809

CDN DISTRIBUTION NETWORK

This work great, but ...

Are there any problems / limitations

of CDNs?

Caching!In computing, a cache (/ˈkæʃ/ KASH) is a component that stores

data so future requests for that data can be served faster; the data stored in a cache might be the results of an earlier computation, or

the duplicates of data stored elsewhere.

WHY CDN?

¨ Caching: Reduced Page Construction Time

¨ Closer: Reduced Latency

¨ Traffic Offloaded: Reduced Loads

¨ Backup: Served even if site is down

¨ Protection: Prevent DoS Attacks

¨ Others: Redirects/Auto-compression/Best-route detection

Where can caching be done?

TYPICAL ARCHITECTURE

Lets draw!

TYPICAL ARCHITECTURE

Improve user experienceReduce server load

TYPES OF CACHES

¨ Web browser

¨ Proxy

¨ CDNs

¨ Reverse Proxies

¨ Web Server’s / Specialized Caches

WE WILL FOCUS ON

Improve user experienceReduce server load

Client-side Performance Testing

To fix performance issues, we need to be able to measure it first!

Measuring Client-side Performance

MEASURING CLIENT SIDE PERFORMANCE

Synthetic Monitoring (& Testing)

Ø WebPageTest.org

Ø SiteSpeed.io

Ø ShowSlow

Ø Google PageSpeed

Ø Chrome Developer Tools

MEASURING CLIENT SIDE PERFORMANCE

Real User Monitoring

Ø Akamai RUM

Ø Monitis RUM

Ø Google Analytics

WebPageTest

WEBPAGETEST – HOSTED SOLUTION

Advantages

Ø Free to use

Ø Global spread

Ø Caters to current web development practices / approaches (responsive / lazy loading / etc.)

https://www.webpagetest.org/

IMPORTANT METRICS

What to Measure?

WebPageTestMetric

Explanation

First reaction

Time to First Byte (TTFB)

Time from the start of the initial navigation until the first byte of the base page is received by the browser (after following redirects).

Content appears

Time to Start Render

Time from the start of the initial navigation until the first non-white content is painted to the browser display.

Pageprocessing completed

DOM Content Ready End

The point when the HTML parser has reached the end of the document which means it has executed any blocking scripts. The CSSOM may not be complete yet.

Full page loaded

Doc Complete Time

The onload event which fires when all of the scripts, css and images defined in the HTML have finished loading (including below-the-fold content).

Refer to WebPageTest documentation for more details:• https://sites.google.com/a/webpagetest.org/docs/using-webpagetest/metrics• https://sites.google.com/a/webpagetest.org/docs/advanced-features/raw-test-results

WEBPAGETEST – HOSTED SOLUTION

Disadvantages

Ø Need to get in the queue of currently executing tests

Ø Can run only against publically available URLs / pages

Ø Limited automation using REST APIs

WEBPAGETEST – PRIVATE INSTANCE

Advantages

Ø Free to use, Open-source

Ø Can run multiple scenarios in parallel (limited by number of agents configured)

Ø Can run against public and private available URLs / pages

Ø Results available for as long as configured

Ø There is no limit on number of tests run per day

WEBPAGETEST – PRIVATE INSTANCE

Disadvantages

Ø Need to setup the WPT server and WPT agents in our own infrastructure, or in AWS

WEBPAGETEST - AUTOMATION

Ø REST API calls

Ø Poll for results / implement call back

Ø Parse summary / detail CSV file to do assertions / validations

Challenges

Ø Managing infrastructure

Ø Polling for results can be time consuming and error prone

YSlow

YSLOW

Advantages

Ø Simple to use (with phantomJS)

Ø Gives reasonably decent information

Ø Easy to hook with Continuous Integration (CI) Server

http://phantomjs.org/download.html

https://github.com/anandbagmar/client-side-perf-tests

YSLOW

Disadvantages

Ø OLD

Ø Does not consider lazy loading / responsive design

Chrome Developer Tools

https://developers.google.com/web/tools/chrome-devtools/

https://developers.google.com/web/tools/chrome-devtools/

Google’s PageSpeedScore

https://developers.google.com/speed/pagespeed/insights/

https://developers.google.com/speed/pagespeed/insights/

GOOGLE PAGE SPEED

Ø De facto standard

Ø Shows opportunities to increase page speed score

Ø Works only for public URLs / pages

RESOURCES

Ø www.webpagetest.org

Ø Page Speed

Ø PhantomJS – YSlow

Ø Sample automation –client-side-perf-tests

Ø Chrome Developer Tools

@BagmarAnand

Blog - essenceoftesting

about.me/anand.bagmar

THANK YOU