No cache headers

[Nicholas Brown]

I have specifically set vBulletin NOT to use no-cache headers but they keep getting added to my templates:

	<!-- no cache headers -->
	<meta http-equiv="Pragma" content="no-cache">
	<meta http-equiv="no-cache">
	<meta http-equiv="Expires" content="-1">
	<meta http-equiv="Cache-Control" content="no-cache">
	<!-- end no cache headers -->

Any ideas?

Example: http://forum.twilight-online.net

[Chris Schreiber]

I believe no-cache-headers are always used for index.php, but the setting should be used for other pages.

[Nicholas Brown]

Thanks Chris.

I had a look through the major templates and its only in forum home - it doesnt bother me - I just thought Id found some sort of bug

Thanks for your time

[fastforward]

This is straignt from the Apache default httpd.conf.

# CacheNegotiatedDocs: By default, Apache sends "Pragma: no-cache" with each
# document that was negotiated on the basis of content. This asks proxy
# servers not to cache the document. Uncommenting the following line disables
# this behavior, and proxies will be allowed to cache the documents.
#
#CacheNegotiatedDocs

Could this have anything to do with it, or is this something else?

[Wayne Luke]

No Cache headers were added to the forumhome template to force Proxies to handle this document properly due to some proxies caching it and serving the stored pages to the wrong sessions.

[jookido]

Originally posted by wluke
No Cache headers were added to the forumhome template to force Proxies to handle this document properly due to some proxies caching it and serving the stored pages to the wrong sessions.

Does this apply to cookied-visits or only session-variable visits?

I was under the impression proxies only stored based on the URL?

[jookido]

Originally posted by fastforward
This is straignt from the Apache default httpd.conf.
CacheNegotiatedDocs: By default, Apache sends "Pragma: no-cache" with each document that was negotiated on the basis of content. This asks proxy servers not to cache the document. Uncommenting the following line disables this behavior, and proxies will be allowed to cache the documents.
#CacheNegotiatedDocs

This may be off-topic, but could this be why my forum graphics keep reloading while I'm surfing the forum? The graphics seem to reload when replying, editting, viewing a thread then hitting back, etc. - seems excessive reloading of graphics to me and I can't figure it out.

Only happens on vB boards, not on any others, so it's not my browser settings (I'm set to "automatic" in IE 5.01).

[tubedogg]

This is only on the forumhome template, meaning the only no-cache is forced is on the first page. It should not affect other pages in the forum.

[fastforward]

I think he's asking if the Apache directive 'CacheNegotiatedDocs' will cause all pages to be reloaded.

I believe the answer is yes... I think I'm not sure if graphics get included in that though. The Apache docs aren't very detailed for this sort of thing. Having said that, I think IE will ignore the headers for graphics and use a cached one unless you do an explicit refresh.

As far I understand, if you have the default Apache config (CacheNegotiatedDocs commented out), any of the caching settings in vB are irrelevant.

Of course, there are also many people running non-Apache servers so it's still a required feature of vB.

[grumpy]

Originally posted by tubedogg
This is only on the forumhome template, meaning the only no-cache is forced is on the first page. It should not affect other pages in the forum.

I had turned on the no-cache headers due to the problem with users logging in as other members (from network caching)

I would guess that having the no-cache headers on the forumhome page alone would solve this problem without having to force them onto all of the other pages, thereby reducing resource usage. Is this right? Or do I need to leave them turned on?

[Mike Sullivan]

Originally posted by grumpy
I would guess that having the no-cache headers on the forumhome page alone would solve this problem without having to force them onto all of the other pages, thereby reducing resource usage. Is this right?

Correct.

[ihelpyou]

My programmer successfully got rid of the ? marks in the Url's for VB.

Reason is because some search engines do not index them.

Now, I have found out also that the no-cache headers are in the forumhome by default.

Since the Google search engine caches all pages in their index, this tag will tell Google to NOT cache the front page.

Google penalizes all pages who have this tag.

I guess that getting rid of the ? marks might be for nat?

[fastforward]

Originally posted by ihelpyou
My programmer successfully got rid of the ? marks in the Url's for VB.

Reason is because some search engines do not index them.

Now, I have found out also that the no-cache headers are in the forumhome by default.

Since the Google search engine caches all pages in their index, this tag will tell Google to NOT cache the front page.

Google penalizes all pages who have this tag.

I guess that getting rid of the ? marks might be for nat?

Have a look at Overgrow's hack for a search engine friendly archive. it will save you a lot of trouble.

[ihelpyou]

Yes, I know. That is what we did.

Still, the no-cache headers Have to be on the front page of the forum as per the responses above.

[fastforward]

Originally posted by ihelpyou
Yes, I know. That is what we did.

Still, the no-cache headers Have to be on the front page of the forum as per the responses above.

Yeah, but by using Overgrow's method, the forum home page doesn't actually get submitted to the search engines; the archive does.

Not the best solution I agree, it would be better if the real forum could simply be submitted, but....