what is the ttl?

Nils Goroll slink at schokola.de
Thu Aug 28 08:13:39 CEST 2014

On 27/08/14 21:19, Per Buer wrote:
> I'm not sure if the term "maxage" is crystal clear (also because it is used to
> denote relative time in Cache-control)

I actually think the term "maxage" is good because it is identical to CC max-age
for all practical purposes: HTTP Cache-Control max-age denotes the maximum live
time of the object from the time corresponding to Age: 0. This is exactly the
semantics I am proposing for (beresp|obj).maxage.

Having said that, I not so sure if users would expect implicit changes to http
headers. IOW, if I had

	set beresp.maxage = 2h;

in my VCL, would anyone expect this to imply something like

	# simplified, should edit the header and not just set it
	set beresp.http.Cache-Control = "max-age=7200"


I tend to think that users should really understand that beresp.something and
beresp.http.something are different things and the documentation should make
clear when we update headers (I guess there is some work to be done here).

At any rate, we must not mix the internal ttl and the (downsteam) caching
directives, the question is if we really need substantially different names if
they basically have the same semantics (for the cache and downstream).


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