http/2 - for tcp/ip geeks stockholm

Daniel Stenberg, May 6th 2015


HTTP Today

HTTP/2 basics

Status

Future

Q&A


Daniel Stenberg

Email: [email protected]: @bagderWeb: daniel.haxx.seBlog: daniel.haxx.se/blog

network hacker at

mailto:[email protected]


Please ask!

… just maybe everything isn't crystal clear at once.


Internet Today

HTTP for everythingThe web has changed significantly since 1996


Request and payload growth

in 4 years...

7777

100100

725K725K

1900K1900K

http

arch

ive.

org


Roundtrip Bonanza


connections per page

38ht

tpar

chiv

e.or

g


Latency adds up

4,000 ms

750 ms

Page load time

Round trip time0 ms 240 ms

Mik

e Be

lshe


Head of line blocking


HTTP 1.1 workarounds


SpritingSpriting


Inlining

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

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


Concatenation

$ cat *.js > single-monster.js


Sharding


Quirky

Annoying for developersAdds layers of toolsHampers cachingDownloads too much


HTTP/2


“Just a new framing layer”

maintains HTTP paradigmshttp:// and https:// URLs cannot be changedHTTP/1.1 servers and clients will be around for decadesProxies must be able to convert 1:1Less optional partsNo more minor version!


Binary

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


Multiplexed (1/2)

•Multiple streams over a single physical connection•Max number of parallel streams set by peer


Multiplexed (2/2)


Better utilization of bandwidth


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


Streams

Dynamic priority

Flow controlAA

BB CC

Dependencies


Server push

Give me HTML please!

Here's HTML for you

Here's CSS for you


Stricter TLS

TLS version 1.2+ only

Stricter cipher suite requirements

No renegotiations


HTTP/2 is not

Mandatory TLSChanging HTTP headers


How will HTTP/2 affect users?

Faster page loadsMore responsive loadingMore HTTPS


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


ImplementationsNghttp2Http2-katanaNode-http2FirefoxHttp2-perlIij-http2AkamaiChromeOpenLiteSpeed

TwitterWiresharkEricsson MSPHttp2 (Go)Http2-goOkHttpTrusterdHaskell http libSteelApp ADC

Google GFEDeuteriumHyperUndertowF5SasazkaLucidH2OWarp

curlCl-http2NettyJettyMicrosoftHttp-2Protocol::HTTP2mod_h2Nginxwget

https://github.com/http2/http2-spec/wiki/Implementations


Will HTTP/2 get widely deployed?

“Look at IPv6”SPDY proved fast growth can happenMajor browsers are on the trainMany sites already did SPDY - likely to go HTTP/2


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 ?


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


Browser support

http://caniuse.com/#feat=http2


My tealeaves tell me...

http://daniel.haxx.se/blog/2015/03/31/the-state-and-rate-of-http2-adoption/

10% at end of 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/


Final recap

Binary and multiplexedPrimarily over TLSUsers won't see a 2 anywhereIt's already here


Thank you!

See also http2 explained http://daniel.haxx.se/http2


Doing good is part of our code


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

http://httparchive.org/


License

This presentation and its contents are licensed under the Creative Commons Attribution 4.0 license: http://creativecommons.org/licenses/by/4.0/

http://creativecommons.org/licenses/by/4.0/

http/2 - for tcp/ip geeks stockholm

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