[development] Refresh rather than re-create D6 cache

[Pierre Rineau]

Le lundi 18 octobre 2010 à 08:04 -0700, Earl Miles a écrit :
> On 10/18/2010 3:22 AM, Tomáš Fülöpp (vacilando.org) wrote:
> > Hi,
> > 
> > In D6, after all caches are cleared, or after a lot of them expire and
> > get emptied by cron, the server load spikes seriously because all such
> > caches need to be re-populated.
> > 
> > Since this happens more and more on sites I work on, I have been
> > thinking about using another approach in my modules, in the sense that
> > caches would be /refreshed/ rather than cleared and re-populated. Each
> > cache refresh would run depending on e.g. a simple variable storing last
> > time stamp of any other cache refresh.
> > 
> > This would assure that a) all cached values would be available at all
> > times, b) caches would never be re-calculated all at the (near) same time.
> > 
> > I am about to write logic for this, but wanted to first check with
> > others in the list -- perhaps some of you know or can point to an
> > elegant solution that already exists.
> 
> This is the Pressflow caching model. When David Strauss first got into
> Drupal, he did a lot of work with this kind of thing, where caching
> wasn't done when requested, but on cron.

If we look at the core functions, we can see Drupal as a framework, it
provides more an API than the caching model itself -even if the caching
model based on massive cache wipeout is implemented in core some
modules- it's up to the module developers to make a good usage of it.
I'd rather implement the refresh caching approach too of course, and
Drupal core does not prevent me to do it.

Pierre.