obj.cacheable vs expires headers?

[Poul-Henning Kamp]

In message <4B707314.5090205 at gmail.com>, Luc Stroobant writes:

>obj.ttl seems to be zero indeed, but I still don't get how his would 
>make the request cacheable. At least it's not the behaviour one would 
>expect?

We distinguish between "can be cached" and "how long should it be cached"
because they are very different questions.

"can be cached" is a matter of correctness, whereas "how long" is 
just a performance issue.

>Secondly: I also thought that Varnish never caches requests with a 
>Set-cookie header?

Varnish has a special kind of cache entries called "hit-for-pass".
This is a cache entry that says that the object can not be cached,
that solves a pile-up issue on busy objects.

The fact that you see zero TTL, can be indicative of the clock on
the varnish-host and the clock on the backend not agreeing what
time it is.  Check your ntpd.


-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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