[TYPO3-english] Time based pulishing

Jigal van Hemert jigal at xs4all.nl
Sun Feb 7 19:04:41 CET 2010


Bernhard Kraft wrote:
> I guess I must have been in some kind of other TYPO3 dimension. But 
> until now I tought the TYPO3 cache "expire" field would get set 
> depending on the lowest tstamp from all content displayed.

I'm sorry, but caching hasn't been the strongest point of TYPO3...

Caching involves a few things:
- a cache key to see if the item is what you're looking for
- an expire timestamp
- a storage and retrieval mechanism
- garbage collection

> So if you have a page showing two content elements, and one changes 
> visibility in 3 hours, and the other on in 2 hours, the expire timestamp 
> will be set to 2 hours in the future, invalidating the cache page as 
> soon as a displayed element changes visibility ....

That would really depend on the part which retrieves and renders the 
content. This part of the system would have the knowledge to determine 
how long it can be cached.

As far as I could determine there is no garbage collection in the old 
(pre-new cache framework) TYPO3 core. Items in the cache are deleted 
before a new one is inserted, but items for which the cache key is never 
matched again stay in the cache storage

The new caching framework hasn't convinced me yet. The reports about 
it's speed (or actually lack of speed) are worrying me.
Having a whole MVC version of a caching mechanism with a db-backend (you 
can select other backends) which uses a lot of subqueries is not the 
recipe for a cache at lightning speed...

I realize that this sounds as at a lot of criticism but for me it's just 
the way things are the moment...

Jigal van Hemert.

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