Cached homepage?

January 7, 2005 11:14 AM

We loaded a new homepage yesterday. However, at least one user is still seeing the old version. What's up?

Initially, I instructed the user on how to clear his cache, figuring that’d solve the problem. The user says he did so, but he still sees the old page (he’s using IE 6.something). We’ve not gotten any other complaints, but that might be simply because other users don’t know we loaded something new. Without access to the user’s machine, is there anything I can suggest he do?

posted by MrMoonPie to Computers & Internet (12 answers total)

Are you or is your ISP running a cache (proxy) server to improve your website's performanec?
posted by AlexReynolds at 11:16 AM on January 7, 2005

Oh, and you might ask him to use a different browser (e.g. Firefox) to see if he runs into the older page. This will help isolate the problem, anyway.
posted by AlexReynolds at 11:18 AM on January 7, 2005

Did you only change the contents of the page, or did you switch to a new webhost/server? If you did the latter, there may be DNS propagation issues. A remarkable number of DNS caches are not up-to-spec, unfortunately.

It's also possible that the user is connecting via a caching proxy (which may or may not be transparent to hir). This would be a different problem than the cache/proxy AlexReynolds refers to. Is there another computer on the complainant's subnet (with similar network settings) that can be tested?
posted by dkg at 11:54 AM on January 7, 2005

It's also possible that the user is connecting via a caching proxy (which may or may not be transparent to hir).

Specifically, if the user is using satellite internet service like Starband, or one of those "faster than 56K!" dial-up services, they may be receiving cached pages instead of the live page.
posted by jessamyn at 12:08 PM on January 7, 2005

I used to see the problem all the time when I worked with teachers in a lab setting. Tell the user to tell their system admin to clear the proxy's cache. To save in bandwidth lots of schools cache pages and then serve the old versions off of the local network. This is great for schools, unless of course they are looking for real-time information or reading blog posts... You might also inform your user to inform their system admin to turn off caching for specific URLs. Good luck.
posted by pwb503 at 12:14 PM on January 7, 2005

Response by poster: Damn, I love AxMe. Thanks, all!
posted by MrMoonPie at 12:27 PM on January 7, 2005

i was wondering if caching proxies added a header to the http stream. however, i can't see how to easily view headers from within a browser anyway, so i guess that doesn't help diagnose things.
posted by andrew cooke at 1:32 PM on January 7, 2005

Andrew, telnet to port 80. You can send commands like HEAD and such to get raw HTTP. For example:

[Support:~] root# telnet hostname 80
Trying hostname...
Connected to .
Escape character is '^]'.
HEAD /nah.html HTTP/1.0

HTTP/1.1 404 Not Found
Date: Fri, 07 Jan 2005 22:00:08 GMT
Server: Apache/1.3.33 (Darwin)
Connection: close
Content-Type: text/html; charset=iso-8859-1

Connection closed by foreign host.
[Support:~] root#
posted by AlexReynolds at 2:05 PM on January 7, 2005

andrew- there's a Firefox extension that does this.
posted by mkultra at 2:07 PM on January 7, 2005

thanks (i know about telnet, but i didn't think it was the kind of thing you could explain down a phone to a user in the hope of getting better diagnostics. i had trouble today with my father which boiled down to him not knowing what i meant when i referred to "the browser window"....)
posted by andrew cooke at 2:25 PM on January 7, 2005

Normally your browser has cached an old page. Instead of connecting to the server and requesting the new page, it is seeing that it has been to that URL before and handing you the (old) copy in the cache.

To FORCE the browser to request the page from the server (thus ignore the cache): Hold down the SHIFT key on your keyboard while clicking the Refresh/Reload button in your browser. Mac: Same instructions, except OPTION key.
posted by spock at 4:17 PM on January 7, 2005

Browser cache
Proxy cache
Provider cache (akami, etc)
Server cache

It's not always easy to tell.
posted by scarabic at 6:06 PM on January 7, 2005