Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
The short but happy lives of TCP and HTTP requests
Search
Starr Horne
September 19, 2014
Programming
4
390
The short but happy lives of TCP and HTTP requests
A talk about network optimization given at the 2014 Golden Gate Ruby Conference.
Starr Horne
September 19, 2014
Tweet
Share
More Decks by Starr Horne
See All by Starr Horne
Ditching the Single Page Application - Madison+Ruby 2015
snhorne
0
250
Ditching the Single Page Application (RubyNation 2015)
snhorne
1
260
SVG Charts and Graphs With Ruby
snhorne
0
200
SVG Charts and Graphs With Ruby
snhorne
0
380
Machine Learning Techniques You Can Use Today
snhorne
4
200
Biggish Data with Rails and Postgresql
snhorne
3
970
Other Decks in Programming
See All in Programming
Porting a visionOS App to Android XR
akkeylab
0
470
データの民主化を支える、透明性のあるデータ利活用への挑戦 2025-06-25 Database Engineering Meetup#7
y_ken
0
360
Hack Claude Code with Claude Code
choplin
4
2.1k
ふつうの技術スタックでアート作品を作ってみる
akira888
1
870
Startups on Rails in Past, Present and Future–Irina Nazarova, RailsConf 2025
irinanazarova
0
120
Agentic Coding: The Future of Software Development with Agents
mitsuhiko
0
100
0626 Findy Product Manager LT Night_高田スライド_speaker deck用
mana_takada
0
170
Discover Metal 4
rei315
2
140
PHPでWebSocketサーバーを実装しよう2025
kubotak
0
290
プロダクト志向なエンジニアがもう一歩先の価値を目指すために意識したこと
nealle
0
130
The Modern View Layer Rails Deserves: A Vision For 2025 And Beyond @ RailsConf 2025, Philadelphia, PA
marcoroth
1
220
Modern Angular with Signals and Signal Store:New Rules for Your Architecture @enterJS Advanced Angular Day 2025
manfredsteyer
PRO
0
220
Featured
See All Featured
KATA
mclloyd
30
14k
Facilitating Awesome Meetings
lara
54
6.4k
The Psychology of Web Performance [Beyond Tellerrand 2023]
tammyeverts
48
2.9k
Agile that works and the tools we love
rasmusluckow
329
21k
The Cult of Friendly URLs
andyhume
79
6.5k
Navigating Team Friction
lara
187
15k
Fashionably flexible responsive web design (full day workshop)
malarkey
407
66k
Building Adaptive Systems
keathley
43
2.7k
A Tale of Four Properties
chriscoyier
160
23k
BBQ
matthewcrist
89
9.7k
Build your cross-platform service in a week with App Engine
jlugia
231
18k
For a Future-Friendly Web
brad_frost
179
9.8k
Transcript
@StarrHorne Hi everybody!! ! I’ll be tweeting this ! slide
deck later at ! @StarrHorne ! ! That’s me!! ! ! ps. Use Honeybadger to monitor your Rails apps for exceptions. (Now my trip is tax deductible!)
@StarrHorne
@StarrHorne
@StarrHorne Short but happy
@StarrHorne Short but happy The lives of HTTP requests
@StarrHorne
@StarrHorne
@StarrHorne
@StarrHorne
@StarrHorne
@StarrHorne
@StarrHorne
@StarrHorne Welcome to the internet I’ll be your guide
@StarrHorne OSI Model
@StarrHorne
@StarrHorne
@StarrHorne
@StarrHorne
@StarrHorne Wires
@StarrHorne Latency ! ! ! Time spent “in the wire”
! ps. it ain’t bandwidth
@StarrHorne Latency ! ! ! Time spent “in the wire”
! ps. it ain’t bandwidth
@StarrHorne Minimum latency (determined by speed of light) http://trollphysics.tumblr.com
@StarrHorne Minimum latency (determined by speed of light) http://trollphysics.tumblr.com
@StarrHorne 299,792,458 m/s (Speed of light in a vacuum) http://trollphysics.tumblr.com
@StarrHorne Don’t call it SOL in a vacuum (That’s something
else) http://trollphysics.tumblr.com
@StarrHorne
@StarrHorne ! 5,578,593(m) ÷ 299,792,458 (m/s) = 0.0186 (s) !
0.0186 * 1000 (ms/s) = 18.6ms ! 18.6 * 2 = 37.2 ms round trip NYC <=> LON Latency (minimum theoretical)
@StarrHorne
@StarrHorne Latency kills UX 100 ms Doesn’t seem instantaneous 250
ms Feels sluggish 500 ms I start to get distracted 1000 ms I’m cussing at the computer
@StarrHorne Easy Move servers closer to users.
@StarrHorne Harder Eliminate Round Trips
@StarrHorne The Data Link
@StarrHorne Bandwidth It must be important. Just look at that
dude’s face!
@StarrHorne Except when it’s not Source: High Performance Browser Networking
( http://bit.ly/high-performance-browser-networking )
@StarrHorne
@StarrHorne The “lots of small files” problem Slower Faster
@StarrHorne Blame the protocols IP Routes packets between computers No
guarantees of delivery. TCP A simulation of a stable network running on top of IP. HTTP Sends one file at a time over TCP connections.
@StarrHorne ! NEW TCP CONNECTIONS ARE EXPENSIVE
@StarrHorne Opening a connection Hey, we should talk Sure, about
what? Awesome. Send me that funny cat pic
@StarrHorne New connection overhead (1 round trip. 20-100ms depending)
@StarrHorne ! YOU’RE NOT GETTING OFF THAT EASY
@StarrHorne CONGESTION CONTROL
@StarrHorne Slow Start
@StarrHorne Let’s see… Thats 10 round trips at (we’ll assume)
40ms latency. Holy crap that’s 400ms!!!
@StarrHorne ! NEW TCP CONNECTIONS ARE EXPENSIVE
@StarrHorne Keep-Alive Browser opens one TCP connection uses it for
multiple HTTP requests. ! ! ! ! ! ! ! …actually, you get 6 connections per domain.
@StarrHorne Your server controls keepalive ! ! Apache: http://bit.ly/apache-ka !
Nginx: http://bit.ly/nginx-ka !
@StarrHorne “Slow start after idle” kills keepalive ! $> sysctl
net.ipv4.tcp_slow_start_after_idle ! $> sysctl -w net.ipv4.tcp_slow_start_after_idle=0
@StarrHorne TCP Tuning Make sure you’re running a recent linux
kernel If you insist: http://bit.ly/tcp-tuning
@StarrHorne HTTP, WTF!?
@StarrHorne >telnet cern.ch 80 GET /cat.txt HTTP/1.0 host: www.esqsoft.globalservers.com
@StarrHorne >telnet cern.ch 80 GET /cat.txt HTTP/1.0 host: www.esqsoft.globalservers.com
@StarrHorne
@StarrHorne
@StarrHorne
@StarrHorne 112 (Requests per webpage on average)
@StarrHorne Browser Caching (Response headers) Last-Modified Tell the browser when
this file was last modified. ETag Supplies an ETag the browser can use to check freshness. Expires Tells the browser to keep the page until a certain date http://bit.ly/http-caching
@StarrHorne 112 (Requests per webpage on average)
@StarrHorne Concatenate JS & CSS (Hello asset pipeline)
@StarrHorne
@StarrHorne
Down to 30 requests (But I feel dirty for some
reason) @StarrHorne
@StarrHorne
@StarrHorne Could we do them CONCURRENTLY? ! ! ! !
! You DO get 6 connections per domain. And you DO know how to make domains.
@StarrHorne farm4.staticflickr.com farm8.staticflickr.com farm8.staticflickr.com farm4.staticflickr.com farm6.staticflickr.com farm3.staticflickr.com http://bit.ly/p-speed
@StarrHorne I guess you could call it an ugly hack
@StarrHorne www.honeybadger.io d3aei7d2k8qp8j.cloudfront.net cdnjs.cloudflare.com d3dy5gmtp8yhk7.cloudfront.net cdnjs.cloudflare.com But we do it
anyway (As a side-effect of using CDNs)
@StarrHorne Move requests out of band (Supported by newer browsers)
! <script async="async" src="/my.js"></script> ! <link rel="prefetch" href=“/big.jpeg"> ! <link rel="prerender" href=“/next.html”> ! <link rel="dns-prefetch" href="//blah.com">
@StarrHorne Summary ! Move your servers closer to your users
(CDNs) ! Make sure keep-alive works ! Keep cookie size small ! Serve fewer files by whatever means necessary ! Shard files across domains if you must !
@StarrHorne The cavalry is on the way!
@StarrHorne SPDY ! Much better at the “lots of small
files” thing ! Supported by many (but not all) clients ! You still need CDNs for geography ! Requires SSL
@StarrHorne HTTP 2.0 ! Coming soon. ! Also focused on
the “lots of small files” problem ! But HTTP 1.4 ain’t going anywhere soon.
@StarrHorne Buy this book ! You can also read it
online for free - legally! ! http://bit.ly/high-performance-browser-networking
@StarrHorne I’ll be tweeting this slide deck later at @StarrHorne