[development] Refresh rather than re-create D6 cache

[Earl Miles]

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.