Etags

Jim,
From http://developer.yahoo.com/performance/rules.html#etags
The end result is ETags generated by Apache and IIS for the exact same component won’t match from one server to another. If the ETags don’t match, the user doesn’t receive the small, fast 304 response that ETags were designed for; instead, they’ll get a normal 200 response along with all the data for the component. If you host your web site on just one server, this isn’t a problem. But if you have multiple servers hosting your web site, and you’re using Apache or IIS with the default ETag configuration, your users are getting slower pages, your servers have a higher load, you’re consuming greater bandwidth, and proxies aren’t caching your content efficiently. Even if your components have a far future Expires header, a conditional GET request is still made whenever the user hits Reload or Refresh.

If you’re not taking advantage of the flexible validation model that ETags provide, it’s better to just remove the ETag altogether. The Last-Modified header validates based on the component’s timestamp. And removing the ETag reduces the size of the HTTP headers in both the response and subsequent requests. This Microsoft Support article describes how to remove ETags. In Apache, this is done by simply adding the following line to your Apache configuration file: FileETag none "

What is my Apache confuguration file? HtAcess file?

Thanks,

Roger

Comments

  1. AMPC says:

    Roger,

    I believe they are referring to your httpd.conf file and many times, the hosting company will not let you change that – depending on your host, etc.

    Best regards,

    Jim.

  2. Actual says:

    Jim,
    My webhost wrote back basically saying that for at least their servers, Etags are a system wide (server wide) setting. So changing etag settings may only be useful for people who have their own server.

    Thanks,

    Roger

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