Web Performance
latency impact
The slower the page , the higher the Bounce rate
Site Speed Is a factor in Google Search
Web Search Delay Experiment - Google And Bing
Avg Search Queries decreased
Revenue/user dropped
User gets used to slow response - an interesting observation
ShopZilla improved page load time - 25% more hits
Treat speed as a feature - part of design from start
Image optimization - Jpeg over png
Bound by latency and not bandwidth if you are at a decent bandwidth
Latency bound by speed of light
Lay shorter cables
HTTP 2.0 Coming up
Requests are multiplexed/prioritized
Higher TCP Window size
Compress Headers...
Correlate business metrics to performance
Stay under 250 ms to feel fast - Usability Engineering
HTTP Request Life
DNS Lookup
Benchmark Site DNS provider
Benchmark ISP DNS Provider
Socket Connect
Bound by latency and not bandwidth , Can we make ther servers closer using CDN or Geo=positional servers
HTTP Request
Can we make the server respond faster?
Content Download
Compressing
HTTP doesn't have multiplexing
HTTP Pipelining/Response Queuing - Head of line blocking - problem
6 connections per host
TCP Initial Congestion Window being increased
TCP Slow Start