Web performance Part 1 "Networking theoretical basis"

Web PerformanceNetworking Theoretical Basis

Andrew Kovalenko & Mykyta Semenistyi

Andrew KovalenkoEducation: Donetsk National University, Physics faculty.Medical Supplier Company “Lyapko”: 2007 - 2008.eGo Creative Media Solutions: 2008 - now.Position: Team Lead in Jaybird Marketing Group Team.

Author of the “KineticJS Starter” book. Author of the “BodyMotivator” project. Software Developer and Web Junkie. Twittering about frontend design and development.

Slogan: Software for the people!

@cybind http://blog.cybind.net

http://blog.cybind.net

Mykyta Semenistyi

Donetsk National Technical UniThesis:“Network optimizations of web apps”

Binary Studio2012 - now

@msemenistyi

Why we need fast websites?

Fast website

better user engagement better user retention

higher conversions

Table of contents➔ latency & bandwidth➔ bufferbloat➔ TCP fast open➔ congestion control & avoidance➔ slow start restart➔ UDP➔ Wireless Networks➔ HTTP

Latency + Bandwidth ≈ Performance

Ilya Grigorik: High Performance Browser Networking

Internet & broadband adoption

More bandwidth doesn’t matter (much)


Latency components

➔ propagation delay

➔ transmission delay

➔ processing delay

➔ queuing delay

Decreasing transatlantic latency with Hibernia Express

TCP/IP➔ retransmission of lost data

➔ in-order delivery

➔ congestion control and avoidance

➔ data integrity

➔ more

Three-way handshake

Three-way handshake


TCP fast open (TFO)

Linux 3.7+

Bufferbloat

Linux 3.5+: CoDel

Flow control


Congestion control & avoidance


Slow start


Slow start restart

The TCP profit

264 ms 96 msIlya Grigorik: High Performance Browser Networking

TCP performance checklist➔ Linux: 3.7+

➔ cwnd size = 10

➔ disable slow-start after idle

➔ enable window scaling

➔ eliminate redundant data transfers

➔ compress transferred data

➔ position servers closer to the user

➔ reuse established TCP connections

UDP

➔ Reliable

➔ Connection-oriented

➔ Segment retransmission and flow control through windowing

➔ Segment sequencing

➔ Acknowledge segments

➔ Unreliable

➔ Connectionless

➔ No windowing or retransmission

➔ No sequencing

➔ No acknowledgement

TCP UDP

Mobile networks


Mobile networks performance checklist

➔ Preserve battery power

➔ Eliminate periodic and inefficient data transfers

➔ Anticipate network latency overhead

➔ Design for variable network interface availability

➔ Burst your data and return to idle

➔ Offload to WiFi networks

HTTP$> telnet google.com 80

Connected to 74.125.xxx.xxx

GET /about/

(hypertext response)(connection closed)

$> telnet website.org 80

Connected to xxx.xxx.xxx.xxx

GET /rfc/rfc1945.txt HTTP/1.0 User-Agent: CERN-LineMode/2.15 libwww/2.17b3Accept: */*

HTTP/1.0 200 OK Content-Type: text/plainContent-Length: 137582Expires: Thu, 01 Dec 1997 16:00:00 GMTLast-Modified: Wed, 1 May 1996 12:45:26 GMTServer: Apache 0.84

(plain-text response)(connection closed)

$> telnet website.org 80Connected to xxx.xxx.xxx.xxx

GET /index.html HTTP/1.1 Host: website.orgUser-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_4)... (snip)Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8Accept-Encoding: gzip,deflate,sdchAccept-Language: en-US,en;q=0.8Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3Cookie: __qca=P0-800083390... (snip)

HTTP/1.1 200 OK Server: nginx/1.0.11Connection: keep-aliveContent-Type: text/html; charset=utf-8Via: HTTP/1.1 GWADate: Wed, 25 Jul 2012 20:23:35 GMTExpires: Wed, 25 Jul 2012 20:23:35 GMTCache-Control: max-age=0, no-cacheTransfer-Encoding: chunked

100 <!doctype html>(snip)

100(snip)

0

GET /favicon.ico HTTP/1.1

0.9 (1991) 1.0 (1996) 1.1 (1999)

Components of HTTP request

WebPageTest.org

WebPerformanceLanding

Page

WebPageTest.org

HTCPCP/1.0The Hyper Text Coffee Pot Control Protocol (HTCPCP)

● controlling● monitoring● diagnosing

coffee pots.

It is specified in RFC 2324, published on 1 April 1998. http://www.error418.org/

http://www.error418.org/

HTTP 2.0➔ March 2012: Call for proposals for HTTP 2.0

➔ September 2012: First draft of HTTP 2.0

➔ July 2013: First implementation draft of HTTP 2.0

➔ April 2014: Working Group last call for HTTP 2.0

➔ November 2014: Submit HTTP 2.0 to IESG as a Proposed

Standard


HTTP 2.0

➔ Improve latency over HTTP 1.1.

➔ Address the "head of line blocking".

➔ One TCP connection.

➔ Semantics of HTTP 1.1.

➔ Interact with HTTP 1.x.

goals


HTTP 2.0


Binary Framing Format

HTTP 2.0


TCP Connection

HTTP 2.0prioritization


➔ 0 - the highest.

➔ 2^31−1 - the lowest.

➔ no spec for implementation

CSS Fonts Icons Images

HTTP 2.0server push


HTTP 2.0


Streams Multiplexing

SPDYgoals

➔ Target 50% reduction in page load time.

➔ Avoid changes to content by website authors.

➔ Avoid changes in network infrastructure.

➔ Develop with the open-source community.

➔ Gather real performance data.


Chrome, FF, IE11, Opera 12.10

SPDY/3