In stark contrast to yesterday’s photos of Hillary Clinton, here are the Barack Obama results. Again, these are only plucked from the first page of results. There were no pictures with popping-out eyeballs, rage, pointing fingers, grimaces, expressions of disdain, surprise, or disgust. Just an all-around, likeable guy.
Unfortunately, on average, people don’t read papers past the pictures. That’s why the USA Today is popular!
I tried out YSlow on some of my web sites recently. It’s pretty well done. Most of the tricks were known to me, but this one trick about ETags (Rule #13) was very interesting to read. Since ETags are indeed useless on my site, I’ve turned them off.
The basic problem is that many web servers (including Apache & IIS) use server-specific mechanisms to compute ETag values. This can break if the files are served from a server farm because each server in the farm can present a different ETag value.
Of course, synchronizing a value may seem easy; but in practice it is not. One suggestion might be to use a MD5 hash of the content. That can be made to work; but it isn’t trivial for a server; it either needs a cache of these, or it needs to re-compute. MD5 is relatively cheap to calculate, but certainly not free. If-Modified-Since solves the problem and requires no computation at all.