YSlow and ETag fix…

Performances are everything!
So every decent web developer probably know Yahoo YSlow and his ranking system.
One of this rule has been particularly a mystery in the last few months… ETag

“An ETag (entity tag) is an HTTP response header returned by an HTTP/1.1 compliant web server used to determine change in content at a given URL. […]

If a site has multiple servers that serve files (i.e. load balancing), a user may request for the same file and get a response from different machines. If the inode is used to generate the ETag, it will be different causing the file to be re-downloaded.”

So how to disable ETags on IIS6? I’ve seen a lot of workaround, ISAPI filters, strange system configurations… until.. I’ve seen the light…

from http://www.turtle.net.nz/blog/post/YSlowUsingIIS/comments

Purvesh – @ 19 Dec 2007 03:46
Hi Guys even no need to implement module to remove Etag just go to Inetmgr and add header in your web site Key = “Etag” Value = “” it will remove Etag from your .js,.Css and .image file.

Simply working and cleaver!



One thought on “YSlow and ETag fix…

  1. Thanks Simone, that’s a useful tip for the future. You are full of these little gems, like using sub-domains for serving images and css.How about publishing a "checklist of performance enhancement techniques for your website before going into production", I’m sure everyone would find it very useful!

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