Http-2
What we need to know
@h6165
Abhishek Yadav
ரூபீ ப்ரோக்ராமர்
Co-organizer: Chennai.rb
HTTP-2
- History
- Technical details
- Affects on Rails
- What we can use
HTTP: History
- 1991: HTTP 0.9 - First documented version
- 1996: HTTP 1.0 (rfc-1945), work starts on HTTP 1.1 (rfc-2068)
- 1997, 1999: HTTP 1.1 release and improvements (RFC-2068, RFC-2616)
- 2007: HTTPbis working group starts work on revising HTTP 1.1
- 2012: First draft of SPDY published
- 2014: HTTPbis submits new spec
- 2015: HTTP-2 published. Google announces stopping support for SPDY
HTTP: History
- 1991: HTTP 0.9 - First documented version
- 1996: HTTP 1.0 (rfc-1945), work starts on HTTP 1.1 (rfc-2068)
- 1997, 1999: HTTP 1.1 release and improvements (RFC-2068, RFC-2616)
- 2007: HTTPbis working group starts work on revising HTTP 1.1
- 2012: First draft of SPDY published
- 2014: HTTPbis submits new spec
- 2015: HTTP-2 published. Google announces stopping support for SPDY
1989: Tim Berners Lee: First GET requests
1996: Browser wars
1996: 40-60 % browsers already on Http1.0
1998: Google founded
1997-2000: Dot Com Bubble
2004: Facebook founded
2004: Gmail launched
2007: Iphone released
2008: Android released
2005: Ruby on Rails-1
2011: Rails 3.1: asset pipeline
2000: Roy Fielding: REST
2008: Chrome launched
2008: HTML5 Draft-1
2014: HTML5 finalized
2013: Chrome-29: SPDY
2011: Websockets shipped
2013: Snowden: NSA
2014: India: Modi as PM: massive use of social media
HTTP: History
- 1991: HTTP 0.9 - First documented version
- 1996: HTTP 1.0 (rfc-1945), work starts on HTTP 1.1 (rfc-2068)
- 1997, 1999: HTTP 1.1 release and improvements (RFC-2068, RFC-2616)
- 2007: HTTPbis working group starts work on revising HTTP 1.1
- 2012: First draft of SPDY published
- 2014: HTTPbis submits new spec
- 2015: HTTP-2 published. Google announces stopping support for SPDY
1989: Tim Berners Lee: First GET requests
1996: Browser wars
1996: 40-60 % browsers already on Http1.0
1998: Google founded
1997-2000: Dot Com Bubble
2004: Facebook founded
2004: Gmail launched
2007: Iphone released
2008: Android released
2005: Ruby on Rails-1
2011: Rails 3.1: asset pipeline
2000: Roy Fielding: REST
2008: Chrome launched
2008: HTML5 Draft-1
2014: HTML5 finalized
2013: Chrome-29: SPDY
2011: Websockets shipped
2005-2015: China+India add 600 million users (450+180).
India is at 350million now
HTTP: History: Conclusion
-
HTTP 1.1 has been stable, and popular
-
Internet has changed, has newer challenges
-
Majority users are on mobile
-
Privacy and security have become political
-
Governments are major stakeholders
-
-
THe web must be efficient and secure
HTTP-2: Technical details
-
HTTP is built on top of TCP
-
A typical web page load in browser:
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Open TCP connection
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Send the GET request
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Receive HTML, parse it, start rendering it
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Open new TCP connection for each asset referred in the html (asset: Javascript, CSS, image, font)
-
-
Server sends data only when browser requests it (exception: Websockets)
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Every new connection creates a massive overheard
HTTP-2: Technical details
-
Popular websites have hundreds of such requests
-
Only upto 6 parallel connections are permitted per domain
HTTP-2: Technical details
- Concatenating JS and CSS (Rails asset pipeline)
-
Creating sprites from images
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Data inlining for images
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Domain Sharding: serving assets from different domains to parallelize
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Caching (Conditional GET, Etag etc)
- HTTP Pipelining
Optimizations to HTTP 1.1
HTTP-2: Technical details
- Connection multiplexing
- Server push
HTTP-2 Proposals
- Header compression
- Binary encoding
HTTP-2: Technical details
- There will be a single, long-lived TCP connection
- The connection will be duplex (TCP is)
HTTP-2 Proposals: connection multiplexing
HTTP-2: Technical details
- All assets can be sent over the same connection. No need to reconnect
- Server can push assets instead of waiting for client to ask
- Client can express preference for certain assets, and get them before others (stream prioritisation)
Connection multiplexing: possible impacts
And
- No need for any of the HTTP 1.1 optimisations - no need of asset-pipeline
- No need of Websockets (https://samsaffron.com/archive/2015/12/29/websockets-caution-required)
HTTP-2: Technical details
- Header compression will some some bandwidth. Little from developer point of view, more as a big picture
- Binary encoding will also make transport efficient. Developers will need more tools for debugging (like Wireshark)
Compression and encoding
- No need for any of the HTTP 1.1 optimisations - no need of asset-pipeline
- No need of Websockets
And
HTTP-2: Technical details
- Spec doesn't require HTTPS, but implementations do.
- All major browsers require TLS mandatorily with HTTP-2
Impacts: HTTPS
HTTP-2: Today
- Implemented by all major browsers
- Except Android browser
HTTP-2: Today
- Implemented by almost all major browsers
- Implemented by Apache and Nginx
-
Supported by default on Cloudflare CDN (out assets are served with HTTP2)
- Server push also announced recently: https://blog.cloudflare.com/announcing-support-for-http-2-server-push-2/
HTTP-2: Today
In Rails world
- Rack is not HTTP-2 compatible
- So no Rack based frameworks can use it
- Some experimental work has been done.
HTTP-2 experiments with Rack
Http-2: what we need to know
By Abhishek Yadav
Http-2: what we need to know
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