[TYPO3-dev] set_no_cache is bad. What's next?

[Bernd Wilke]

On Thu, 29 Mar 2007 19:53:24 -0500, R. van Twisk wrote
with subject "Re: [TYPO3-dev] set_no_cache is bad. What's next?":

[...] 
> Hey Franz,
> 
> nice explanation, and I go a bit OT and I will go to the extreme.

I don't think so. 

> The above method also means that if you have 50.000 posts,
> you will loose the complete cache for all posts, just because
> somebody else added a single other post.....
> 
> I think I am right.... am I???

partly ;-)
not all pages are affected, but how to decide which one are?
where will a new posting have affects?
in the overview (last posting: ...)
in a threadview (reply to ...), 
if this is a view with just one posting, it will affect the neighbour, or
maybe all posting if all messages in the thread are linked.

I think this is the problem: how to decide which pages are really affected?
another extension, the same problem:
tt_news: one new news. which overview has to be cache-cleared? in this case
the related single-views will be updated, so they must be edited by hand.


> It just means that if a typo3 installation is mostly community driven.
> Which means only a couple of pages but lots of forums and dynamic
> content from single plugins etc etc.

you have to clear cache for all overview-content, because it might be
affected by the new record. 
This could be the main part of a page (forum-overview), but it can also be
a small part (linked thread of message).
All single-view content should be unaffected and so doesn't need to be
cache-cleared.

if a developer decides well which kind of contentblock is displayed
(overview or single-record) and sets the appropiate caching it should be
enough.

> Then the cache is almost useless if you have frequent additions to the 
> board.
> And then all of a sudden google  and yahoo wants to index
> all content (means the 50.000 different views of the board) then the server
> will be highly loaded.....

on a very big community, there will be a lot of overviews in different
kinds. leaving all overviews always uncached may increase server-load. 

But that belongs on the activity. there might be a range where the best
solution could be: clear cache on every edit/insert. 
but having much activity, there will be a state, where a record every
second is edited or inserted and you can leave all overviews uncached.
queuing clear caches will be only overhead.

just my 0.02€

Bernd
-- 
http://www.bernd-wilke.net