A walkthrough of various application performance tuning tools and a good workflow for where to start, from a presentation at WindyCityRails 2011 in Chicago, IL.
See the video, and more Web and Ruby/Rails Performance info at www.RailsPerformance.com
-John McCaffrey
Videogame localization & technology_ how to enhance the power of translation.pdf
Windycityrails page performance
1. Faster Page
Performance
John McCaffrey
@J_McCaffrey
http://spkr8.com/t/8314
2. Agenda
• Intro
• Performance 101
• Performance tuning workflow
• Performance features in Rails 3, 3.1
• Considerations for Mobile and HTML 5
• Q&A
3. Intro
• Doing Rails since 2007
• 4th time presenting at WindyCityRails
o 2008: Advanced Firebug and JS unit testing
o 2009: PDF Generation in Rails
o 2010: Rails Performance Tuning
o 2011: Faster Page Performance
• Addicted to Performance Tuning
• railsperformance.blogspot.com
@J_McCaffrey
• Feedback: speakerrate.com railsperformance@gmail.com
4. Intro
• Doing Rails since 2007
• 4th time presenting at WindyCityRails
o 2008: Advanced Firebug and JS unit testing
o 2009: PDF Generation in Rails
o 2010: Rails Performance Tuning
o 2011: Faster Page Performance
• Addicted to Performance Tuning
• railsperformance.blogspot.com
@J_McCaffrey
• Feedback: speakerrate.com railsperformance@gmail.com
5. Intro
• Doing Rails since 2007
• 4th time presenting at WindyCityRails
o 2008: Advanced Firebug and JS unit testing
o 2009: PDF Generation in Rails
o 2010: Rails Performance Tuning
o 2011: Faster Page Performance
• Addicted to Performance Tuning
• railsperformance.blogspot.com
@J_McCaffrey
• Feedback: speakerrate.com railsperformance@gmail.com
7. Intro
• A little about you, and the people around you
8. Intro
• A little about you, and the people around you
• You are all smarter than I am
9. Intro
• A little about you, and the people around you
• You are all smarter than I am
• Try hard to Network today, meet cool people
10. Intro
• A little about you, and the people around you
• You are all smarter than I am
• Try hard to Network today, meet cool people
• Eat lunch with someone new, invite someone
into your ‘crowd’, go to the After Party!!
11. Quick Poll
• Work on a Rails application
• Have been doing Rails for less than 6 months? 1yr? 2yrs? 4yrs?
• Testing Rspec? cucumber? Test::Unit? CI?
• Write Javascript frequently? jQuery? Prototype? js testing?
• Working with Rails 3 or Rails 3.1
• Work on Mobile (native or web)
• Working with HTML 5
12. Quick Poll
• Raise your hand if you Want to learn more
• Stand up if you’d like to meet up with
others and share what you’ve learned
13. Quick Poll
• Raise your hand if you Want to learn more
• Stand up if you’d like to meet up with
others and share what you’ve learned
Don’t knock over your coffee!
14. Help me, Help you!!
• Improving page loading time
• Sql query tuning, indexes or DB tuning
• Rails 3 and 3.1
• HTML 5 and CSS 3
• NoSQL
17. Introduce yourself
(toyou’re from
someone new)
• Name & Where
Photo by @monty_ksycki
18. Introduce yourself
(toyou’re from
someone new)
• Name & Where
• Most important thing you want to
get out of WindyCityRails
Photo by @monty_ksycki
19. Introduce yourself
(toyou’re from
someone new)
• Name & Where
• Most important thing you want to
get out of WindyCityRails
• Only 2mins for this!!!!
Photo by @monty_ksycki
20. Agenda
• Intro
•
•
Performance 101
Performance tuning workflow
• Performance features in Rails 3, 3.1
• Considerations for Mobile and HTML 5
34. Perf Tuning Pledge
• “I will MEASURE before and after”
• “I will document and share the findings”
35. Perf Tuning Pledge
• “I will MEASURE before and after”
• “I will document and share the findings”
• “WE will decide to monitor it, fix it, or just
forget it”
36. Agenda
• Intro
• Performance 101
• Performance tuning workflow
• Performance features in Rails 3, 3.1
• Considerations for Mobile and HTML 5
39. Improving page load
Yslow (Firefox and Chrome)
http://developer.yahoo.com/yslow/
Page speed (Firefox and Chrome)
http://code.google.com/speed
Dynatrace (IE and Firefox)
http://ajax.dynatrace.com
Webpagetest.org (IE, Chrome, Firefox)
40. Improving page load
Yslow (Firefox and Chrome)
http://developer.yahoo.com/yslow/
Page speed (Firefox and Chrome)
http://code.google.com/speed
Dynatrace (IE and Firefox)
http://ajax.dynatrace.com
Webpagetest.org (IE, Chrome, Firefox)
41. Improving page load
Yslow (Firefox and Chrome)
http://developer.yahoo.com/yslow/
Page speed (Firefox and Chrome)
http://code.google.com/speed
Dynatrace (IE and Firefox)
http://ajax.dynatrace.com
Webpagetest.org (IE, Chrome, Firefox)
42. Improving page load
Yslow (Firefox and Chrome)
http://developer.yahoo.com/yslow/
Page speed (Firefox and Chrome)
http://code.google.com/speed
Dynatrace (IE and Firefox)
http://ajax.dynatrace.com
Webpagetest.org (IE, Chrome, Firefox)
43. Improving page load
Yslow (Firefox and Chrome)
http://developer.yahoo.com/yslow/
Page speed (Firefox and Chrome)
http://code.google.com/speed
Dynatrace (IE and Firefox)
http://ajax.dynatrace.com
Webpagetest.org (IE, Chrome, Firefox)
44. Improving page load
Yslow (Firefox and Chrome)
http://developer.yahoo.com/yslow/
Page speed (Firefox and Chrome)
http://code.google.com/speed
Dynatrace (IE and Firefox)
http://ajax.dynatrace.com
Webpagetest.org (IE, Chrome, Firefox)
80-85% of the time is spent on the front-end
45. Page load rules
1. Minimize HTTP Requests
2. Use a Content Delivery Network
3. Add an Expires or a Cache-Control Header
4. Gzip Components
5. Put StyleSheets at the Top
6. Put Scripts at the Bottom
7. Avoid CSS Expressions
Steve Souders 8. Make JavaScript and CSS External
9. Reduce DNS Lookups
10. Minify JavaScript and CSS
11. Avoid Redirects
12. Remove Duplicate Scripts
13. Configure ETags
14. Make AJAX Cacheable
15. Use GET for AJAX Requests
16. Reduce the Number of DOM Elements
17. No 404s
18. Reduce Cookie Size
58. Save your Waterfall!
HTTP Archive format
(HAR)
• Export options www.softwareishard.com/blog/har-adopters
• Firebug
• IE9
• Chrome
• Webpagetest.org
• Har viewer www.softwareishard.com/har/viewer
• Compare multiple files
59. Save your Waterfall!
HTTP Archive format
(HAR)
• Export options www.softwareishard.com/blog/har-adopters
• Firebug
• IE9
• Chrome
• Webpagetest.org
• Har viewer www.softwareishard.com/har/viewer
• Compare multiple files
Did I mention that its important to measure?
60. Solutions
• Gzip
• Combine and minify js and css
• Load css first, js at the bottom
• Optimize images and use css sprites
• Use a cdn for static assets
• Defer javascript loading
62. Deferred loading of
javascript
• Load only the minimum necessary javascript first
• Load the rest of the javascript asynchronously
• Pre-load and pre-cache javascript and images for
the next pages
63. Deferred loading of
javascript
• Load only the minimum necessary javascript first
• Load the rest of the javascript asynchronously
• Pre-load and pre-cache javascript and images for
the next pages
bit.ly/non-blocking-js
www.stevesouders.com/blog/2009/04/27/loading-scripts-without-blocking
64. Leverage
✓ Those changes improve the
performance across multiple
requests
✓ Well tested, well understood
✓ Continues to be useful as new
features are added, won’t get
in your way
65. Leverage
✓ Those changes improve the
performance across multiple
requests
✓ Well tested, well understood
✓ Continues to be useful as new
features are added, won’t get
in your way
71. What I’m looking for
• What is the average response time
• What is the slowest request
• What request makes up the majority of the
work the server is doing
• Are there good candidates for caching?
72. Common culprits
• Not leveraging the database
• Too much memory
• Too many queries
• Generally slow code
• Loading more fields than needed
73. N +1
clients = Client.limit(10)
clients.each do |client|
puts client.address.postcode
end
74. N +1
1 query to clients = Client.limit(10)
load the clients clients.each do |client|
puts client.address.postcode
end
75. N +1
1 query to clients = Client.limit(10)
load the clients clients.each do |client|
puts client.address.postcode
end
1 query for each address (x10)
76. N +1
1 query to clients = Client.limit(10)
load the clients clients.each do |client|
puts client.address.postcode
end
1 query for each address (x10)
clients = Client.includes(:address).limit(10)
clients.each do |client|
puts client.address.postcode
end
77. N +1
1 query to clients = Client.limit(10)
load the clients clients.each do |client|
puts client.address.postcode
end
1 query to 1 query for each address (x10)
load the clients
clients = Client.includes(:address).limit(10)
clients.each do |client|
puts client.address.postcode
end
78. N +1
1 query to clients = Client.limit(10)
load the clients clients.each do |client|
puts client.address.postcode
end
1 query to 1 query for each address (x10)
load the clients
clients = Client.includes(:address).limit(10)
clients.each do |client|
puts client.address.postcode
end
1 query to get all 10 Addresses!
80. Libraries
• Document why you have it
• Remove unused, reduce dependencies
• Pick between duplicate tools
• Try to stay current
• Rvm, bundler and git branches for testing
• “Is it safe to upgrade that library” - find the
right balance of tests to answer this
88. Culprits
• Too many queries
• No indexes on the key data
• Not optimized for how the db ‘thinks’
• Not enough server memory for sorting
• Trying to do too much in one query
90. Testing
• Measure first!
• Make performance tuning changes in the
most tested parts of the app
• Have the most important parts of your app
well-tested, so tuning will be easier
• Well-tested code tends to be well factored
93. Javascript is powerful
• Most hate for javascript is really a hatred of
the browser and DOM interaction
94. Javascript is powerful
• Most hate for javascript is really a hatred of
the browser and DOM interaction
• Javascript is driving a lot of very cool things
95. Javascript is powerful
• Most hate for javascript is really a hatred of
the browser and DOM interaction
• Javascript is driving a lot of very cool things
• Node.js
96. Javascript is powerful
• Most hate for javascript is really a hatred of
the browser and DOM interaction
• Javascript is driving a lot of very cool things
• Node.js
• Backbone
97. Javascript is powerful
• Most hate for javascript is really a hatred of
the browser and DOM interaction
• Javascript is driving a lot of very cool things
• Node.js
• Backbone
• sproutCore
98. High performance js
• UI thread is responsible for js
and UI updates
• Understand Repaint and Reflow
triggers
• Benchmarks for browser
performance
• Dom Scripting
• Memory and cpu usage
104. jQuery Top Issues
• Poor selector usage
• $(‘#Id, form, input’) Id and element are fast
• $(‘.classname’) causes full scan in IE5-8
105. jQuery Top Issues
• Poor selector usage
• $(‘#Id, form, input’) Id and element are fast
• $(‘.classname’) causes full scan in IE5-8
• show() and hide() often slower
than .addClass(“show”) or .addClass(“hide”)
106. jQuery Top Issues
• Poor selector usage
• $(‘#Id, form, input’) Id and element are fast
• $(‘.classname’) causes full scan in IE5-8
• show() and hide() often slower
than .addClass(“show”) or .addClass(“hide”)
• .each() often slower than regular ‘for’ loop
107. jQuery Top Issues
• Poor selector usage
• $(‘#Id, form, input’) Id and element are fast
• $(‘.classname’) causes full scan in IE5-8
• show() and hide() often slower
than .addClass(“show”) or .addClass(“hide”)
• .each() often slower than regular ‘for’ loop
• Avoid extra queries by caching selector
108. jQuery Top Issues
• Poor selector usage
• $(‘#Id, form, input’) Id and element are fast
• $(‘.classname’) causes full scan in IE5-8
• show() and hide() often slower
than .addClass(“show”) or .addClass(“hide”)
• .each() often slower than regular ‘for’ loop
• Avoid extra queries by caching selector
• Avoid manipulating the Dom in a loop, try to
append all at once (with a wrapping element)
112. Browser Comparison
• jsperf.com
• Compare js performance across browsers
• http://jsperf.com/queryselectorall-vs-
getelementsbytagname
• jsfiddle.net (full page structure)
• http://jsfiddle.net/addyosmani/BFeMN/
These tools make benchmarks easier and repeatable
113. Agenda
• Intro
• Performance 101
• Performance tuning workflow
• Performance features in Rails 3, 3.1
• Considerations for Mobile and HTML 5
114. Performance features in Rails 3
• Separation of framework, only load what you need
• New Active Record Arel query structure
• http://www.slideshare.net/tenderlove/zomg-why-
is-this-code-so-slow
• Bundler
• Ruby 1.9.2 (with patch for faster Rails 3 load)
118. Performance features in Rails 3.1
• JQuery by default
• Prepared statement caching
• New Asset Pipeline
119. Performance features in Rails 3.1
• JQuery by default
• Prepared statement caching
• New Asset Pipeline
• railscasts.com/episodes/279-understanding-the-asset-pipeline
120. Performance features in Rails 3.1
• JQuery by default
• Prepared statement caching
• New Asset Pipeline
• railscasts.com/episodes/279-understanding-the-asset-pipeline
• Http Streaming
121. Performance features in Rails 3.1
• JQuery by default
• Prepared statement caching
• New Asset Pipeline
• railscasts.com/episodes/279-understanding-the-asset-pipeline
• Http Streaming
• railscasts.com/episodes/266-http-streaming
123. Html 5 is a big deal!
• More tags and native behavior
• Native form elements
• Client side Validation
• http://slides.html5rocks.com
• http://mrdoob.com/91/Ball_Pool
• http://bodybrowser.googlelabs.com
• http://www.chromeexperiments.com/
127. Mobile
• Good for ‘desktop’ and mobile
• Reduce network calls
• Only load what you need
128. Mobile
• Good for ‘desktop’ and mobile
• Reduce network calls
• Only load what you need
• Cache as much as you can (HTML5 AppCache)
129. Mobile
• Good for ‘desktop’ and mobile
• Reduce network calls
• Only load what you need
• Cache as much as you can (HTML5 AppCache)
• Specific to mobile
130. Mobile
• Good for ‘desktop’ and mobile
• Reduce network calls
• Only load what you need
• Cache as much as you can (HTML5 AppCache)
• Specific to mobile
• Javascript is roughly 10X slower on mobile
131. Mobile
• Good for ‘desktop’ and mobile
• Reduce network calls
• Only load what you need
• Cache as much as you can (HTML5 AppCache)
• Specific to mobile
• Javascript is roughly 10X slower on mobile
• Click events delay for 300-500ms, use touch instead
132. Mobile
• Good for ‘desktop’ and mobile
• Reduce network calls
• Only load what you need
• Cache as much as you can (HTML5 AppCache)
• Specific to mobile
• Javascript is roughly 10X slower on mobile
• Click events delay for 300-500ms, use touch instead
• Smaller Cache (IOS only caches pages under 25kb
unzipped)
135. javascript
• Find a mentor: http://jsmentors.com
• play around: http://jsfiddle.net/addyosmani/BFeMN
• run tests and share them: jsperf.com
• speed of different tools: dante.dojotoolkit.org/taskspeed
136. Thank You!
Any Questions?
railsperformance.blogspot.com
railsperformance@gmail.com
@J_McCaffrey
Hinweis der Redaktion
\n
\n
love making apps faster\nIf I don’t cover the thing you are looking for, come find me, twitter\n
love making apps faster\nIf I don’t cover the thing you are looking for, come find me, twitter\n
picture of windy city audience that I took in 2009\n\nYou all have had different experiences, and there are others here today that you can share with, and can share with you. The value of a conference is partially in the presentations, but mostly in the networking.\nIf you play your cards right, you’ll probably meet 2-3 people that will give you useful info today, and another 2-3 people that will give you critical info in the next 2-3 months\n\nThere are a lot of smart people in here, take the time to meet them. \nTake the time to meet some new people, eat lunch with a different crowd, step out of your comfort zone\ntrust me, you’ll get a lot more out of the conference if you do\n
picture of windy city audience that I took in 2009\n\nYou all have had different experiences, and there are others here today that you can share with, and can share with you. The value of a conference is partially in the presentations, but mostly in the networking.\nIf you play your cards right, you’ll probably meet 2-3 people that will give you useful info today, and another 2-3 people that will give you critical info in the next 2-3 months\n\nThere are a lot of smart people in here, take the time to meet them. \nTake the time to meet some new people, eat lunch with a different crowd, step out of your comfort zone\ntrust me, you’ll get a lot more out of the conference if you do\n
picture of windy city audience that I took in 2009\n\nYou all have had different experiences, and there are others here today that you can share with, and can share with you. The value of a conference is partially in the presentations, but mostly in the networking.\nIf you play your cards right, you’ll probably meet 2-3 people that will give you useful info today, and another 2-3 people that will give you critical info in the next 2-3 months\n\nThere are a lot of smart people in here, take the time to meet them. \nTake the time to meet some new people, eat lunch with a different crowd, step out of your comfort zone\ntrust me, you’ll get a lot more out of the conference if you do\n
picture of windy city audience that I took in 2009\n\nYou all have had different experiences, and there are others here today that you can share with, and can share with you. The value of a conference is partially in the presentations, but mostly in the networking.\nIf you play your cards right, you’ll probably meet 2-3 people that will give you useful info today, and another 2-3 people that will give you critical info in the next 2-3 months\n\nThere are a lot of smart people in here, take the time to meet them. \nTake the time to meet some new people, eat lunch with a different crowd, step out of your comfort zone\ntrust me, you’ll get a lot more out of the conference if you do\n
Raise your hand: Who thinks audience participation is lame?\n\nTrust me, this is a good warm up, and it won’t take long\nEveryone Hands up, \nOk hands down\n
Of those people that have tried these things, let’s see if we can find a few that might be ok with sharing what they’ve learned. Find them out in the hallways and get to know them\n\nDon’t knock over your coffee\n
“Raise your hand if you want to learn more about”\n“Stand up if you feel you know something about this, and wouldn’t mind chatting about it and sharing what you’ve learned”\n\n
\n
\n
\n
\n
\n
When we talk about performance tuning, we are not just talking about slow apps that need to be fixed, we are also talking about ‘normal’ apps that are tuned to really fly.\n\n1 sec delay, on 100k a day could lead to 2.5mil lost\nWe’re talking about cost and value\n
100ms faster lead to 1% increase in revenue for amazon\n400ms faster lead to 9% increase in traffic (more traffic, more ads, more eyeballs)\n\n
went from 6sec to 1.2\nsped up development and deployment \nand consolidated hardware\n
\n
They tell others about their bad experience, “That’s not the kind of ‘viral’ message you want”\n\nPage performance is in the mind and behaviors of real users\n
\n
\n
talk about cost and value\npremature opt. is usually high upfront cost with low long term value\nlooking for low upfront cost, low long-term cost, high long term value\n\nleverage\nthings that will improve more requests, or improve more frequently called\n\nDon’t go back to your project and make a bunch of changes in the name of Performance\n
talk about cost and value\npremature opt. is usually high upfront cost with low long term value\nlooking for low upfront cost, low long-term cost, high long term value\n\nleverage\nthings that will improve more requests, or improve more frequently called\n\nDon’t go back to your project and make a bunch of changes in the name of Performance\n
Measuring and monitoring is not premature, go for good enough measuring\n\nWe should know these things about our apps\n
Make it easy for the team to track general performance numbers\ncommit message should read I saw that this was taking x amount of time, so I changed it. now it takes Y\n
Make it easy for the team to track general performance numbers\ncommit message should read I saw that this was taking x amount of time, so I changed it. now it takes Y\n
Make it easy for the team to track general performance numbers\ncommit message should read I saw that this was taking x amount of time, so I changed it. now it takes Y\n
\n
I got feedback from several people that they would like me to cover the general flow and hotspots.\nI’m going to go over my basic workflow, referencing some of the tools I use and what I look for\n
These tools analyze your page and give you some hints at how to improve the page loading time for first time and repeat visitors\nThey are definitely the first thing you should do, even if you think you ‘know’ what the real problem is, these tools will confirm it, and allow you and the rest of the team to measure performance over time.\n\nIts important to use tools/instrumentation that everyone on the team has visibility to.\nYou’ll have less arguments about performance impacts if you can teach them how to measure\n
These tools analyze your page and give you some hints at how to improve the page loading time for first time and repeat visitors\nThey are definitely the first thing you should do, even if you think you ‘know’ what the real problem is, these tools will confirm it, and allow you and the rest of the team to measure performance over time.\n\nIts important to use tools/instrumentation that everyone on the team has visibility to.\nYou’ll have less arguments about performance impacts if you can teach them how to measure\n
These tools analyze your page and give you some hints at how to improve the page loading time for first time and repeat visitors\nThey are definitely the first thing you should do, even if you think you ‘know’ what the real problem is, these tools will confirm it, and allow you and the rest of the team to measure performance over time.\n\nIts important to use tools/instrumentation that everyone on the team has visibility to.\nYou’ll have less arguments about performance impacts if you can teach them how to measure\n
These tools analyze your page and give you some hints at how to improve the page loading time for first time and repeat visitors\nThey are definitely the first thing you should do, even if you think you ‘know’ what the real problem is, these tools will confirm it, and allow you and the rest of the team to measure performance over time.\n\nIts important to use tools/instrumentation that everyone on the team has visibility to.\nYou’ll have less arguments about performance impacts if you can teach them how to measure\n
These tools analyze your page and give you some hints at how to improve the page loading time for first time and repeat visitors\nThey are definitely the first thing you should do, even if you think you ‘know’ what the real problem is, these tools will confirm it, and allow you and the rest of the team to measure performance over time.\n\nIts important to use tools/instrumentation that everyone on the team has visibility to.\nYou’ll have less arguments about performance impacts if you can teach them how to measure\n
These tools analyze your page and give you some hints at how to improve the page loading time for first time and repeat visitors\nThey are definitely the first thing you should do, even if you think you ‘know’ what the real problem is, these tools will confirm it, and allow you and the rest of the team to measure performance over time.\n\nIts important to use tools/instrumentation that everyone on the team has visibility to.\nYou’ll have less arguments about performance impacts if you can teach them how to measure\n
maybe you want to break the rules and optimize for repeat over new users\ndescribe the groupings\nless network calls\nless data\nleverage how the browser works (ordering, host limit, rendering, etc)\nnow sometimes you want to intentionally break the rules\noptimize for repeat over new users\n\n
Dark green = DNS lookup (there is such a thing as bad dns)\nOrange = TCP connection handshake (shows you the cost of making all those requests)\nBright Green = Time to first byte coming back (shows you how long the server was thinking)\nBlue = content download (how long it all took)\n\n
orange bars: cost of handshake, turn on ‘keep-alives’, load less\nlong bright green bars: waiting for first byte, maybe a CDN would help\nlong blue bars: long time to load the data, slow server IO, slow network, lost packets\n\n
This is from chrome, the tan is blocking\nwhen js is running, nothing else can update\n
This is from chrome, the tan is blocking\nwhen js is running, nothing else can update\n
This is from chrome, the tan is blocking\nwhen js is running, nothing else can update\n
This is from chrome, the tan is blocking\nwhen js is running, nothing else can update\n
If you load conditional comments for IE stylesheets, check this article, look at your waterfall for IE\nthe workaround is to put an empty conditional comment after the doctype, or before other includes\n
If you load conditional comments for IE stylesheets, check this article, look at your waterfall for IE\nthe workaround is to put an empty conditional comment after the doctype, or before other includes\n
If you load conditional comments for IE stylesheets, check this article, look at your waterfall for IE\nthe workaround is to put an empty conditional comment after the doctype, or before other includes\n
If you load conditional comments for IE stylesheets, check this article, look at your waterfall for IE\nthe workaround is to put an empty conditional comment after the doctype, or before other includes\n
If you load conditional comments for IE stylesheets, check this article, look at your waterfall for IE\nthe workaround is to put an empty conditional comment after the doctype, or before other includes\n
If you load conditional comments for IE stylesheets, check this article, look at your waterfall for IE\nthe workaround is to put an empty conditional comment after the doctype, or before other includes\n
If you load conditional comments for IE stylesheets, check this article, look at your waterfall for IE\nthe workaround is to put an empty conditional comment after the doctype, or before other includes\n
Save your har file regularly, and load it up to see what’s going on\nThere are browser differences in what gets loaded, and when, so keep track of what you did.\nexample of ‘good enough’ measurement\nhttp://www.softwareishard.com/har/viewer/ \nyou can drag multiple har files and compare them\nhttp://www.softwareishard.com/blog/har-adopters/ list of har adopters\nyou can download and run it locally if you want to\n
Save your har file regularly, and load it up to see what’s going on\nThere are browser differences in what gets loaded, and when, so keep track of what you did.\nexample of ‘good enough’ measurement\nhttp://www.softwareishard.com/har/viewer/ \nyou can drag multiple har files and compare them\nhttp://www.softwareishard.com/blog/har-adopters/ list of har adopters\nyou can download and run it locally if you want to\n
tools like jammit, sprockets to help\ntouch on Rails 3.1 asset pipeline\n\n\n\n\n
the single most important performance coding pattern for today's websites is to load js async\nhttp://www.stevesouders.com/blog/2009/04/27/loading-scripts-without-blocking/\n\nImage of Steve Souders looking up at the quote\ndifferent techniques\ngmail technique\n\nThis deserves more attention\nThis can be used in conjunction with generic, cacheable base pages\n
the single most important performance coding pattern for today's websites is to load js async\nhttp://www.stevesouders.com/blog/2009/04/27/loading-scripts-without-blocking/\n\nImage of Steve Souders looking up at the quote\ndifferent techniques\ngmail technique\n\nThis deserves more attention\nThis can be used in conjunction with generic, cacheable base pages\n
the single most important performance coding pattern for today's websites is to load js async\nhttp://www.stevesouders.com/blog/2009/04/27/loading-scripts-without-blocking/\n\nImage of Steve Souders looking up at the quote\ndifferent techniques\ngmail technique\n\nThis deserves more attention\nThis can be used in conjunction with generic, cacheable base pages\n
The hallmarks of the ‘sweet spot’\nYour servers and network are doing less work, freeing it up to do something else\nThe client’s browser is doing less work\nrun these tools against your app, and save your har file, to keep an eye on trends\n
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Its ok for some requests to be slow, month-end reporting, etc\nLooking for consistency, \nhow long has this been happening\ncan I reproduce it on the production server, and can I reproduce it locally\n\nlower level\nwhat is the memory footprint\nis it the code, db, or partials that is taking so long?\n
a few examples from itest, where pagination call was in the wrong spot\n\nauthors.posts.comments \ntoo much ruby\ntoo many queries\n\nThere is a cost to have all of the fields loaded, both from a memory footprint stand point, and a datatype conversion. \nIf all you are doing is a readonly view of the object, use :select to narrow to just the part you care about\n
http://guides.rubyonrails.org/active_record_querying.html\n\nSELECT * FROM clients LIMIT 10\nSELECT addresses.* FROM addresses\n  WHERE (addresses.client_id IN (1,2,3,4,5,6,7,8,9,10))\n\n
http://guides.rubyonrails.org/active_record_querying.html\n\nSELECT * FROM clients LIMIT 10\nSELECT addresses.* FROM addresses\n  WHERE (addresses.client_id IN (1,2,3,4,5,6,7,8,9,10))\n\n
http://guides.rubyonrails.org/active_record_querying.html\n\nSELECT * FROM clients LIMIT 10\nSELECT addresses.* FROM addresses\n  WHERE (addresses.client_id IN (1,2,3,4,5,6,7,8,9,10))\n\n
http://guides.rubyonrails.org/active_record_querying.html\n\nSELECT * FROM clients LIMIT 10\nSELECT addresses.* FROM addresses\n  WHERE (addresses.client_id IN (1,2,3,4,5,6,7,8,9,10))\n\n
http://guides.rubyonrails.org/active_record_querying.html\n\nSELECT * FROM clients LIMIT 10\nSELECT addresses.* FROM addresses\n  WHERE (addresses.client_id IN (1,2,3,4,5,6,7,8,9,10))\n\n
http://guides.rubyonrails.org/active_record_querying.html\n\nSELECT * FROM clients LIMIT 10\nSELECT addresses.* FROM addresses\n  WHERE (addresses.client_id IN (1,2,3,4,5,6,7,8,9,10))\n\n
http://guides.rubyonrails.org/active_record_querying.html\n\nSELECT * FROM clients LIMIT 10\nSELECT addresses.* FROM addresses\n  WHERE (addresses.client_id IN (1,2,3,4,5,6,7,8,9,10))\n\n
http://guides.rubyonrails.org/active_record_querying.html\n\nSELECT * FROM clients LIMIT 10\nSELECT addresses.* FROM addresses\n  WHERE (addresses.client_id IN (1,2,3,4,5,6,7,8,9,10))\n\n
http://guides.rubyonrails.org/active_record_querying.html\n\nSELECT * FROM clients LIMIT 10\nSELECT addresses.* FROM addresses\n  WHERE (addresses.client_id IN (1,2,3,4,5,6,7,8,9,10))\n\n
You can tell what railscasts were popular when a rails project was created, its like rings on a tree\n\nActs_as_tree, acts_as_list, acts_as_state_machine all provide awesome functionality, but the design is an abstraction to handle most cases. You have to look at your particular case to see what the best solution is\nGems and plugins add to the memory footprint even if you don’t call the code. \nuse Rvm, git branches, bundler to test\nnewer versions of libraries\nnewer versions of Rails\nNewer versions of Ruby\nSet up a ‘profiling’ branch with\nrack bug\nquery-trace\nmetric-fu\nyou might even play around with jruby, and use some of the profiling tools of the JVM\n
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After doing the page load improvements, db query tuning, and indexes is usually where I make the biggest impact\n\nMost apps are heavy read, but we often chose to run calculations and lookups at read time.\n\nOne approach is to segment or shard the data, the system runs the same queries, but the underlying access plan is different\nshard by customer\npartition by date, etc\n
I’ve seen issues where its a 32bit mysql running on 64 bit\n\nhttp://www.mysqlperformanceblog.com/2008/07/25/the-1-mistake-hosting-providers-make-for-mysql-servers/\n
Shows me the total time\nsequential scans and index scans\nand where the time was spent\nI chopped this one a bit to fit on the slide, the real one is here http://explain.depesz.com/s/cRm\n
Shows me the total time\nsequential scans and index scans\nand where the time was spent\nI chopped this one a bit to fit on the slide, the real one is here http://explain.depesz.com/s/cRm\n
In rails I don’t see the last one as much, but sometimes its just much faster to do one query to get all the ids, and another query to select on those ids. You just have to try it and see what’s fastest (with prod data)\n
sweet spot effort vs. cost\nwell-factored code usually reduces dependencies and duplication\n\n
We realize the benefits of using javascript MVC design\nbackbone, sproutcore,\n
We realize the benefits of using javascript MVC design\nbackbone, sproutcore,\n
We realize the benefits of using javascript MVC design\nbackbone, sproutcore,\n
We realize the benefits of using javascript MVC design\nbackbone, sproutcore,\n
We realize the benefits of using javascript MVC design\nbackbone, sproutcore,\n
You’ve found the issue, now try to test it on other browsers, share it\n
You’ve found the issue, now try to test it on other browsers, share it\n
You’ve found the issue, now try to test it on other browsers, share it\n
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Identity map\n
Identity map\n
Identity map\n
Identity map\n
Identity map\n
Identity map\n
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refer to items from google io conf.\nangry birds\nthat song video\n\ncss3 spiderman and other cool things\n\nGPU hardware acceleration: layout, CSS3 transitions, 3D transforms\nanimations can be done faster and look better\n