Re: Prevent caching of a page



Scripsit MG:

The page in question (http://www.samurdermysteries.co.za/gal.htm)
doesn't contain any pictures at all. It is a page of links. On this
page I put new link to the newly created page containing the
pictures. It is this page of links that has the problem. The newly
created link is not visible to visitors who recently visited the page.

OK, so it is not about images at all. Whether the newly added link refers to a page with images is immaterial, as is its being a link. So this is about caching the HTML document. Then the classical advice is that you should read the classical treatise on practical caching:
http://www.mnot.net/cache_docs/

To take a shortcut, you could first check the current cacheability, using e.g.
http://www.ircache.net/cgi-bin/cacheability.py
This shows, in this case, that there is no explicit cacheability information, and caches will probably make freshness guesses based on the last modification of the page. For most purposes, this is just fine.

Authors often get wild about caches when they edit a page and have difficulties in seeing the modified version. They don't realize that visitors don't experience such problems. When I visit your page, I normally get it from your server, though at times I might get it from my ISP proxy cache if some other user visited it very recently, e.g. 10 minutes ago, and in that case I would get it somewhat faster - and I might get it even when your server is temporarily unreachable. The odds of getting an old version that way are very small. But to the _author_, the situation is different.

Do you still want to defeat caching?

Note that nothing that you put into the HTML document can affect the way an ISP's caching proxy works, for example, since the proxy doesn't even look at the _content_, only HTTP headers.

--
Jukka K. Korpela ("Yucca")
http://www.cs.tut.fi/~jkorpela/
Join the Clueless Club by quoting this sig!

.



Relevant Pages

  • Re: [PHP] Aggressive PHP Smart Caching
    ... main uses for caches at this time [as caching pertains to php]. ... is a design choice to make it easier to scale your application ...
    (php.general)
  • Re: how does a proxy work
    ... It depends largely on the configuration of the proxy in question. ... network with more than a couple machines should have a caching web proxy ... and to filter sites your company finds ...
    (microsoft.public.windowsxp.general)
  • Re: How to remount a USB drive
    ... there're caches that need flushing out. ... Not post write caches on a memory stick there aren't. ... The box that is the USB memory stick, or whatever it was you were ... one on windows marked for caching) has a read cache but not a write cache. ...
    (uk.comp.sys.mac)
  • cache problem
    ... to use the proxy the caching stops. ... have to use the proxy for these clients since they are ... Is there a way to disable the caching that I am seeing ... >server is sending the file out. ...
    (microsoft.public.windows.server.sbs)
  • Re: Caching live stream at proxy server.
    ... I have functions ready for caching ... but, while debugging i found that, only proxy functions get called. ... When client #2 connects to cache proxy, you want the cache proxy server to ...
    (microsoft.public.windowsmedia.server)