[Zope] CacheManagers are cool :)

[Seb Bacon]

> anybody tried expiring an object,? say after 300 secs, the cached object
> expires, get invalidated and a new cached object is created when somebody
> requested the page.
> is there any simple way to expire a RAM Cache?

haven't tried this yet.

> also, for those who tried caching.  what do you guys do?  cache
> the methods
> that make up the bigger method?  or just cache the bigger method?
>
> e.g dtml method a is made from method b, c, d,...n
> do you cache a, or selectively cache b and/or c, d, ...

it depends on what's in each element.  the design of the caching system is
such that you can have as fained-grained a control as you wish.  the
decision is entirely up to you.  my fairly amateurish tests suggest that the
benefits of caching only really manifest themselves at high levels of
concurrency.  if the method (a) contains a little logic, items (b),(c) and
(d) are images, and the whole page is very frequently accessed, you'd
probably benefit from caching (a) in RAM, and using the HTTP Cache manager
for the other elements.  OTOH, you could expect proxies and browser caches
to handle elements such as images fairly well, so I imagine most of the
benefit would come from caching only the element of the page which contains
the logic.  If the page is accessed only a hundred times a day, you will see
little benefit from caching it, at the cost of some memory on your server.

in a scenario where (b), (c) and (d) each contain their own snippets of
logic, you would be wise to cache them all.  Otherwise you would lose the
benefits of caching (a), because to build the page, Zope is still making
hits to disk each time.

well, that's how I assume it works, anyway.  time for more tests, i think...

seb