[TYPO3-english] Typoscript conditions, caching and performance

[Mathias Schreiber [wmdb]]

Am 08.08.11 07:17, schrieb Rik Willems:
> This is one of those sources I was talking about.
> Although the text looks clear I have one question remaining. When there
> is a condition, are both true and false cached and stored at that time
> or only when that part of the condition is met?

TYPO3 does not pre-cache any situation.
When a page is requested, it basically builds a hash from all conditions 
(Typoscript conditions, logged in usergroups, language keys, GET vars 
etc) and then checks if a cache entry for this hash is present.
If so, it will display the cached page, if not, it will generate the 
cache and store it for future use.

Now one important thing to remember is CHR, cache hit ratio.
If you have a low of different usergroups combinations every single one 
of these combinations will generate a cache entry, thus lowering the CHR.

We had a case like this where the CHR was extremely low (like 10%) so 
having all the caching overhead was worse than catering up more hardware.

Also: Lots of conditions will make your site slower, since they are 
processed uncached.
Imagine a browser check... no sense in caching the check :)

Bottomline:
Use as few conditions as possible and/or use faster way to do things 
(like redirecting with apache fx.)

cheers
Mathias

-- 
Ernesto, Nov. 9th 2010:
"In the graphics generation routines of TYPO3 *anything* could cause a
side effect."