1. SPDY: 146% faster
Valentin V. Bartenev
NGINX, Inc.

2. 2 / 16
What the fu in the world
is going on SPDY?
● Binary protocol
● Developed by Google
● Transport layer for HTTP
● Works over TLS
– proxy transparency

3. 3 / 16
A long time ago in a galaxy far,
far away....
● Simple sites, light pages
– no CSS, no JavaScript
– a few graphics
● Slow clients, low capacity last miles
p.s. http://wayback.archive.org/

4. 4 / 16
The world is changing
● Broadband internet connections
● Fat pages
● Browser arms race
● Hard-to-please customers

5. 5 / 16
What Is to Be Done?
● Metrics: RTT, TTFB
● Browser caching
● Keepalive, pipelining
● JS/CSS catenation, sprites, inlining,
data URI scheme
● Async loading, AJAX
● Domain sharding
● Proxying, CDN

6. 6 / 16
Pipelining

7. 7 / 16
SPDY features
● Multiplexing
● HTTP headers compression
● Flow control
● Server push

8. 8 / 16
Multiplexing

9. 9 / 16
HTTP headers compression
● Zlib
● Dictionary
● CRIME
- zero compression level
- zlib hack
- new algorithm in SPDY/4

10. 10 / 16
Lulz
● Partial alignment
● 24 bits for all headers, but 32 bits for
every header name and value
● Blowing hot & cold with priority
● Mistakes in comp. dictionary
● Chrome flow control fail

11. 11 / 16
To be or not to be?
● HTTPS ready
● Lot of external resources per page
● Big RTT
● Stats from WordPress:
– faster than HTTPS,
– but slower than plain HTTP

12. 12 / 16
SPDY in NGINX
● Sponsored and tested by Automattic
– WordPress, Gravatar
– Wordpress.com: 70 000 rps, 15+ Gbit/sec
● Timeline
– March 2012: the work has started
– 15 June: first public release
– 18 August: last stable version

13. 13 / 16
Results
SPDY Server Survey Nginx
9% Google
4000
Apache
3500
Other
3000
SPDY domains
2500
2000
1500
1000
500
0
May October
89%

14. 14 / 16
How-To
● OpenSSL 1.0.1+ (NPN support required)
● http://nginx.org/patches/spdy/ (temporary)
server {
listen 433 ssl spdy;
ssl_certificate path/to/server.crt;
ssl_certificate_key path/to/private.key;
#spdy_headers_comp 1;
}

15. 15 / 16
Detect SPDY in browser
● Chrome/Chromium:
– window.chrome.loadTimes().wasFetchedViaSpdy;
– chrome://net-internals/#spdy
● Firefox:
– SPDY indicator
var req = new XMLHttpRequest();
req.open('HEAD', document.location, false);
req.send();
req.getResponseHeader('X-Firefox-Spdy');

16. 16 / 16
¿Questions?
Valentin V. Bartenev
http://vbart.info/, ne@vbart.ru
Btw,
is hiring!
Please submit your CV to
maxim@nginx.com