Presented in RootConf 2015

1. Quick primer on http2
Cyrus Dasadia @ExtremeUnix

2. HTTP 1.1 est. 1999
- Piggybacks on TCP
- No efficient reusability
- Head-of-line blocking Problem

3. Enter HTTP/2 (httpbis)
- Started off from SPDY/3 draft
- HTTPbis working on draft-17
- Will not have any minor versions
- No change in http(s) URI pattern

4. How does it look?
Handshake

5. How does it look?
It’s all binary, love.

6. Seriously, how does it look?
Frames:
image: tools.ietf.org/html/draft-ietf-httpbis-http2-17

7. Frames
Basic protocol unit of HTTP/2 is Frame
● HEADERS
● DATA
● SETTINGS
● PUSH_PROMISE
● GOAWAY
● ...few more

8. Header Frames
- Request Pseudo-headers :method, :scheme, :
authority, :path
- Response Pseudo-headers :status
- Cookie header field uses semicolon “;”
- Header compression (HPACK)

9. Header Frames
Comparing HTTP/1.1 response with HTTP/2:
image: tools.ietf.org/html/draft-ietf-httpbis-http2-17

10. Streams
- One TCP connection to rule them all!
- Concurrent, bi-directional and unilateral
- Streams can be prioritized and re-prioritized
- Stream can have dependency hierarchy
- Flow control avoids interference

11. Streams

12. Streams
Simple Prioritization Stream Hierarchy
image: tools.ietf.org/html/draft-ietf-httpbis-http2-17

13. PUSH_PROMISE

14. Current state:
- Google, Twitter, are on http2
- Facebook, HN are on SPDY
- cURL, ATS, Nghttp2
- Firefox, Chrome

15. Will it help me?
- No more than one connection per client
- Connection reusability by multiplexing
- TLS with a reduced hop

16. Will it help me?
DIY http2 CDN?

17. P.S. Keep an eye out for RFC-7540
Thank you!

18. References:
http://tools.ietf.org/html/draft-ietf-httpbis-http2-17
http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-12
http://chimera.labs.oreilly.com/books/1230000000545/ch12.html
http://daniel.haxx.se/http2/
https://github.com/http2/http2-spec/wiki/Implementations
http://tools.ietf.org/rfc/rfc7540
http://tools.ietf.org/rfc/rfc7541
https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=51810161
http://wiki.squid-cache.org/Features/HTTP2
http://nginx.com/blog/how-nginx-plans-to-support-http2/
https://github.com/tatsuhiro-t/nghttp2