Webgeeks notes from Mon Dec 7th

[Matthew Nuzum]

I might classify Monday's meeting as one of the best of the year. Some
great content, great discussion and a great presentation by Dan.

I took notes about his performance optimizations. They're brief, but
if there's a nugget of something you wish you knew more about feel
free to ask and maybe someone who was there can expand.

DNS lookups cost ms
Set expires headers, cache-control, etags
Strict html has to be downloaded before validated? relaxed loads inline
Relying on etags means an extra HEAD request to the server, better is
far-future expires headers
(make sure to use this for just production, can mess you up during dev)
(use different file names / versioned urls)
It's 2009, use gzip (just note that IE6 may have probs)
Only 2 concurrent connections per domain according to http spec, so
split your content over a couple domains, but be careful, don;t kill
your caching strategy by Serving the same file from diff domains to
the same user,
law of diminishing returns says this doesn,t scale infinetly
Sharding is splitting your data across different servers
Serve your static content through a cookieless domain
Some browsers won't paralallize javascript - defer loading and/or
execution if you can
ajax requests aren't caught by this
look for code that uses callbacks to execute code - it has a greater
chance of been executed in parallel
Proxy caching is good, more below...
Apache not the best for static content... its very versatile, great on
the backend
Nginx - pronounced engine x - reverse proxy, ssl, virtual hosting
good for serving static assets, including w/ssl
can simplify virtual hosting
has rules for caching if you put it between your users and your virtual hosts
Wordpress.com is behind just one nginx proxy (?)
Nginx config is very similar to apache
Will do auto gzipping, allowing apache to have module disabled
Memcached plugin for wordpress slightly preferred over supercache
use apc / xcache to speed up php
cloud front on top of s3 will lower your latency, definitely use
versioned urls/names though
Use firebug, yslow and google code speed

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Matthew Nuzum
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