[PATCH] stale-while-revalidate updated

Nils Goroll slink at schokola.de
Thu Aug 28 08:26:39 CEST 2014

On 27/08/14 23:34, Geoff Simmons wrote:
> I think I'm unsure about what we're striving for in Varnish 4 --
> wasn't the goal to move as much caching policy as possible out to VCL,
> with good defaults in builtin.vcl?

I see a bit of a tendency that we are moving towards having C code provide
good/better defaults, still allowing VCL to modify them.

This definitely is the case with fgs' proposed patch, vcl_backend_fetch still
has the final word.

But, yes, s-w-r can be done in VCL already (and it really is a good question if
we shold just add it to the builtin.vcl). s-i-e, I think, needs additional C
support to allow for a VCL implementation (see my post "restarting for bad
synchronous responses").

Some header mangling (Vary, Etag) we are doing in fetch processors at the moment
is the exact contrary - VCL control is reduced (limited to vcl_deliver) until we
get explicit fetch processor pushes (which phk is planning for).


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