HTTP/2 - background, overview, status and the future. Slides from the talk I did for TCP/IP Geeks Stockholm on May 6 2015.

1. Daniel Stenberg, May 6th
2015

2. Daniel Stenberg, May 6th
2015
HTTP Today
HTTP/2 basics
Status
Future
Q&A

3. Daniel Stenberg, May 6th
2015
Daniel Stenberg
Email: daniel@haxx.se
Twitter: @bagder
Web: daniel.haxx.se
Blog: daniel.haxx.se/blog
network hacker at

4. Daniel Stenberg, May 6th
2015
Please ask!
… just maybe everything isn't crystal clear at once.

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2015
Internet Today
HTTP for everything
The web has changed significantly since 1996

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2015
Request and payload growth
in 4 years...
7777
100100
725K725K
1900K1900K
httparchive.org

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2015
Roundtrip Bonanza

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2015
connections per page
38
httparchive.org

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2015
Latency adds up
4,000 ms
750 ms
Page
load
time
Round
trip
time0 ms 240 ms
MikeBelshe

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2015
Head of line blocking

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2015
HTTP 1.1
workarounds

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2015
SpritingSpriting

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2015
Inlining
.icon1 {
background: url(data:image/png;base64,<data>) no-repeat;
}
.icon2 {
background: url(data:image/png;base64,<data>) no-repeat;
}

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2015
Concatenation
$ cat *.js > single-monster.js

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2015
Sharding

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2015
Quirky
Annoying for developers
Adds layers of tools
Hampers caching
Downloads too much

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2015

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2015
HTTP/2

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2015
“Just a new framing layer”
maintains HTTP paradigms
http:// and https:// URLs cannot be changed
HTTP/1.1 servers and clients will be around for
decades
Proxies must be able to convert 1:1
Less optional parts
No more minor version!

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2015
Binary
•No more telnet tricks
•Easier framing
•TLS and compression anyway...
•Wireshark inspector
•A handful set frame types, like HEADERS and DATA

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2015
Multiplexed (1/2)
•Multiple streams over a single physical connection
•Max number of parallel streams set by peer

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2015
Multiplexed (2/2)

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2015
Better utilization of bandwidth

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2015
Header compression
•HTTP headers are big and are growing
•HTTP 1 had no header compression
•TCP slow start and initial window size
•Headers are notoriously repetitive
•Cookies
•HPACK
•Not a CRIME victim
•Padding

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2015
Streams
Dynamic priority
Flow control
AA
BB CC
Dependencies

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2015
Server push
Give me HTML please!
Here's HTML for you
Here's CSS for you

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2015
Stricter TLS
TLS version 1.2+ only
Stricter cipher suite requirements
No renegotiations

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2015
HTTP/2 is not
Mandatory TLS
Changing HTTP headers

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2015
How will HTTP/2 affect users?
Faster page loads
More responsive loading
More HTTPS

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2015
How will HTTP/2 affect web development?
HTTP/1 work-arounds hurt HTTP/2 perf
Need to do separate tweaks
Optimal HTTP/2 usage will need some time

31. Daniel Stenberg, May 6th
2015
Implementations
Nghttp2
Http2-katana
Node-http2
Firefox
Http2-perl
Iij-http2
Akamai
Chrome
OpenLiteSpeed
Twitter
Wireshark
Ericsson MSP
Http2 (Go)
Http2-go
OkHttp
Trusterd
Haskell http lib
SteelApp ADC
Google GFE
Deuterium
Hyper
Undertow
F5
Sasazka
Lucid
H2O
Warp
curl
Cl-http2
Netty
Jetty
Microsoft
Http-2
Protocol::HTTP2
mod_h2
Nginx
wget
https://github.com/http2/http2-spec/wiki/Implementations

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2015
Will HTTP/2 get widely deployed?
“Look at IPv6”
SPDY proved fast growth can happen
Major browsers are on the train
Many sites already did SPDY - likely to go
HTTP/2

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2015
Schedule
Firefox 35 – enabled by default January 13th
Chrome 40 – enabled by default January 21st
IESG approved on February 18th
HTTP/2 final RFC in Q2 2015 ?

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2015
HTTP/2 – May 6th
2015
All browser support seen so far only over HTTPS
Firefox: HTTP/2 in 10%of all HTTP responses1
HTTP/2 is used 10 times more than HTTP/1.0
Google: HTTP/2 used in 18% of global traffic2
HTTP/2 is supported by 44% of browsers in use right now
IPv6: 6.6% today, almost 20 years after first RFC3
1. Rough and not statistically sound numbers from Mozilla Telemetry data for Firefox 36.
2. Rough and rapidly changing numbers in an evolving climate. Graciously provided by Google.
3. https://www.google.com/intl/en/ipv6/statistics.html

35. Daniel Stenberg, May 6th
2015
Browser support
http://caniuse.com/#feat=http2

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2015
My tealeaves tell me...
http://daniel.haxx.se/blog/2015/03/31/the-state-and-rate-of-http2-adoption/
10% at end of 2015

37. Daniel Stenberg, May 6th
2015
Future
HTTP/2 lays the foundation for the future
Time to drop legacy HTTP “mistakes”?
HTTP/3 can happen faster
QUIC
The HTTP Workshop (Münster, 27-30 July 2015)
https://httpworkshop.github.io/

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2015
Final recap
Binary and multiplexed
Primarily over TLS
Users won't see a 2 anywhere
It's already here

39. Daniel Stenberg, May 6th
2015
Thank you!
See also http2 explained
http://daniel.haxx.se/http2

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2015
Doing good is part of our code

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2015
Credits
✗
HTTP and TCP trend numbers from
http://httparchive.org
✗
RTT / page load data from Mike Belshe
✗
HTTP/2 usage numbers by Google and Firefox
Telemetry
✗
Lego pieces borrowed from my kids

42. Daniel Stenberg, May 6th
2015
License
This presentation and its contents are licensed under
the Creative Commons Attribution 4.0 license:
http://creativecommons.org/licenses/by/4.0/