Cloud Performance: Guide to Tackling Cloud Latency [Cloud Connect - Chicago 2012]

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Performance matters. And in the cloud, performance matters more than ever—layers of complexity and third-party, shared environments separate users from applications. Services are elastic, which means you can have any SLA you want, as long as you're willing to design it yourself. And you can have a fast application, too—if you're willing to deal with the bill at the end of the month. So how should you think about cloud performance? In this in-depth workshop on the performance of cloud computing, three cloud computing and Internet performance experts—Steve Riley (Riverbed, Amazon), Hooman Beheshti (Strangeloop, Radware) and Alistair Croll (Coradiant, CloudOps)—take you on a tour of the challenges on-demand computing poses to reliable, fast user experiences. What you'll learn: - The new models of delay, capacity, and uptime that on-demand computing requires - What and how to measure when it comes to performance, and how to think about metrics - Where delay happens across the cloud environment - How shared computing and back-end contention affect user experience - What the WAN and the Application Delivery Network mean in a cloudy compute model - How to spread load and optimize application front-ends to speed up applications

Transcript of Cloud Performance: Guide to Tackling Cloud Latency [Cloud Connect - Chicago 2012]

Web Acceleration and Front End Optimization

Cloud Connect 2012 Chicago

Hooman Beheshti VP Technology, Strangeloop

hooman@strangeloopnetworks.com

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 2

Web Application Acceleration

•  Means lots of things to lots of people –  TCP optimization

–  Caching –  HTTP protocol optimization

–  Compression –  Etc

•  We’ll focus on “front-end” issues –  Front-end Optimization (FEO) –  Sometimes called WCO or WPO

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 3

Better Performance = Better Business

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 4

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 5

Impact of page load time on average daily searches per user

-0.70%

-0.60%

-0.50%

-0.40%

-0.30%

-0.20%

-0.10%

0.00%

50ms pre-header

100ms pre-header

200ms post-header

200ms post-ads

400ms post-header

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 6

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 7

Impact of additional delay on business metrics

-5.00% -4.50% -4.00% -3.50% -3.00% -2.50% -2.00% -1.50% -1.00% -0.50% 0.00%

50 200 500 1000 2000

Perc

ent c

hang

e

Added delay

Queries per visitor Query refinement Revenue per visitor Any clicks Satisfaction

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 8

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 9

Shopzilla had another angle

� Big, high-traffic site ◦ 100M impressions a day ◦ 8,000 searches a

second ◦ 20-29M unique visitors

a month ◦ 100M products

�  16 month re-engineering ◦  Page load from 6 seconds

to 1.2 ◦  Uptime from 99.65% to

99.97% ◦  10% of previous hardware

needs

http://en.oreilly.com/velocity2009/public/schedule/detail/7709

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 10

5-12% increase in revenue

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 11

Mobile Case Study

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 12

Customer Pro"le

•  Top 200 Internet retailer, US based •  Target geography: US and Europe •  $3B in revenue

•  30,000 employees

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 13

Page Views by Mobile Device

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 14

Experiment

•  Induce delay on HTML –  200msec, 500msec, 1000msec

•  Apply to small percentage of tra#c

•  12 weeks

•  Monitor impact on key business metrics

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 15

Results

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 16

Impact on Bounce Rate

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 17

Impact on Returning Visitors

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 18

More Details

•  http://www.webperformancetoday.com/2011/11/23/case-study-slow-page-load-mobile-business-metrics/

•  http://velocityconf.com/velocityeu/public/schedule/detail/21632

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 19

What Is FEO?

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 20

What Is FEO?

0 6 12

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 21

What Is FEO?

0 6 12

DNS TTFB

TCP Connection

Download

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 22

What Is FEO?

0 6 12

Back End: The time from when the request is made by the browser to last byte of the HTML response

Front End: Everything after the HTML arrives

Important Timers: Start Render

onload (Document Complete)

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 23

Google’s Waterfall Chart

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 24

Measurement/Tools

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 25

Waterfall Analysis

•  Best way to address front-end problems is to diagnose your site/application through waterfall analysis

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 26

Waterfall Tools: webpagetest.org

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 27

Waterfall Tools: HTTPWatch

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 28

Waterfall Tools: Firebug

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 29

Waterfall Tools: WebKit Dev Tools

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 30

Waterfall Tools: PCAP2HAR

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 31

Measurement

•  Performance measurement is still a challenge •  Synthetic performance “proxies”

–  Backbone testing services –  Desktop tools and browser plugins –  Browser-based tests

•  Real User Monitoring (RUM) –  Using real user beacons –  Services available –  Can build your own –  Now a part of Google Analytics –  Caveat: need lots of data!

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 32

Front End Problems

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 33

Front End Performance Problems

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 34

Front End Performance Problems

•  Latency: –  every round trip incurs a latency

penalty

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 35

Front End Performance Problems

•  Latency: –  every round trip incurs a latency

penalty

•  Payload:

–  last mile bandwidth isn’t in"nite

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 36

Front End Performance Problems

•  Latency: –  every round trip incurs a latency

penalty

•  Payload:

–  last mile bandwidth isn’t in"nite

•  Caching: –  coming back to the page must be

much faster

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 37

Front End Performance Problems

•  Latency: –  every round trip incurs a latency

penalty

•  Payload:

–  last mile bandwidth isn’t in"nite

•  Caching: –  coming back to the page must be

much faster

•  Rendering: –  browser work takes time

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 38

Client Platforms

•  Desktop vs Mobile –  Desktop browsers have more access to compute

resources –  Larger screens

–  Faster networks (lower latency)

•  The problems are often similar –  Addressing them is often di$erent

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 39

Addressing Front End Problems

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 40

Latency

•  TTFB (Time To First Byte) •  Every fetch incurs the latency penalty •  Two ways to address the problem:

–  Reduce latency –  Get rid of round trips

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 41

CDN

•  Global network of caching proxies that gets content closer to all your users

•  The closer the asset, the lower the latency

•  Lots of vendors to choose from

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 42

CDN

Per object TTFB savings of ~50%

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 43

CDN: because physics!!

•  Well understood way to leverage science

•  Mitigates the latency problem by reducing it for the majority of your users

•  Less e$ective when it comes to mobile users

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 44

Mobile Networks (3G example)

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Resource Consolidation

•  Eliminating round trips altogether also "ghts the latency problem, often more e$ectively

Combine images into fewer "packages"

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 46

Resource Consolidation

•  A number of consolidation techniques –  Images (sprites)

–  JavaScript/CSS consolidation/concatenation –  Inlining (DataURI for images)

–  MHTML (IE only)

•  Browser makes one request for the “package”

•  HTML is marked up so the browser can get individual resources from inside the package

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 47

Payload Reduction

•  Bytes still need to get from server (cloud or otherwise) to client

•  Ways to reduce bytes: –  HTTP compression

–  JS/CSS mini"cation –  Image compression (lossless or lossy)

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 48

Payload Reduction

•  Any reduction in bytes will make pages load faster

•  This is particularly important with mobile clients

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 49

Browser Caching

•  The browser cache is a resource seldom used optimally

•  Reasons why we generally don’t do good browser caching –  Caching rules are often complicated

–  We never want to server stale content

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 50

Browser Caching

•  Use long expiry on static objects –  Served from origin

–  Served from CDN

•  Invalidation framework is a must –  Protect against serving stale content

–  Example: versioning

/images/image.jpg à /images/image.jpg?v=00001

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 51

Browser Caching on Mobile Platforms

•  Di$erent than desktop

•  The cache available to the browsers is relatively small

•  Use localStorage instead of browser cache –  A programmable cache, unlike HTTP object caches

–  Limited size (~2.5MB per domain) –  Good for caching CSS/JS, and small images

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 52

Rendering Issues

•  More complicated

•  The order of events in the browser make a di$erence to how fast a page looks –  Put things in the optimal order for rendering

•  Deferral –  CSS and JS (sometimes images) –  Asynchronous JavaScript

•  Above the fold vs below the fold

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 53

Some Examples

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 54

Before and After Waterfalls

58 roundtrips à 5 roundtrips

4.2 seconds à 1.1 seconds

57 roundtrips à 4 roundtrips

3.2 seconds à 0.7 seconds

First Time Visitor

Repeat Visitor

Before FEO After FEO

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 55

Mobile Example

•  Velocity Conference 2012

•  Step-wise acceleration of O’reilly’s site (for a mobile phone on 3G) –  Start with the original site (purposely made worse)

–  Add CDN –  Add resource consolidation and payload reduction

–  Add deferrals

•  Examine impact of each

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 56

What Does it Look Like?

http://youtu.be/iPtbU1KvLjM

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 57

Original Site + CDN

15.29 sec 13.7 sec

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 58

Add Consolidation and Payload Reduction

13.7 sec

9.47 sec

To onload Before After

# of resources 92 28

KBytes 727 417

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 59

Add Deferral

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 60

Add Deferral

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 61

Add Deferral

9.47 sec

3.6 sec

5.56 sec

2.2 sec

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 62

What Does It Look Like?

MobileFEO = +Consolidation and payload reduction MobileFEO2 = +Deferrals

http://youtu.be/zTTxdAtbhsg

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 63

Summing up…

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 64

Sounds Really Easy!

•  It’s not!

•  Some techniques are just di#cult to implement

•  Optimizing for performance sometimes requires signi"cant dev resources –  Mortal companies can’t a$ord to sacri"ce new

feature cycles

•  Maintenance and upkeep is a constant problem –  Every version to roll out will need optimization

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 65

FEO Automation Industry

•  Solutions available to automatically do this stu$

•  Multiple deployment options –  Software/Hardware/Service

–  Cloud apps will use either service or software

•  The goal is to “"x the code” for performance, automatically

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 66

It Gets Complicated

•  Rewriting HTML can break pages

•  You have to do this stu$ based on browser –  Play to the strength of each browser (supported

techniques, etc) –  Stay away from their weaknesses (bugs, undocumented

issues, etc) –  Mobile is its own beast

•  Optimizing once per page isn’t enough –  First view (cold cache) –  Repeat view (warm cache) –  User "ow

© 2010 Strangeloop Networks Strangeloop. Faster Websites. Automatically. 67

When Looking For FEO Automation

•  Do your research, and understand your needs

•  Understand the deployment model and how disruptive it will be to you, if at all

•  Are there provisions in place for breaking pages

•  Granularity in functionality: –  Browser-based optimization –  mobile –  "rst/repeat views –  transaction %ows

•  Choose what’s right for you, based on your needs

Thank You

68

hooman@strangeloopnetworks.com