On Fri, May 23, 2014 at 10:44 AM, Poul-Henning Kamp <[email protected]> wrote: > In message <[email protected]>, "Poul-Henning Kamp" writes: >>In message >><caeh05vb--ig-hp+uw0pfzefw0f6f+0qxwmxyd-wq3g6g4zd...@mail.gmail.com>, Dag >>Haavi Finstad wri >>tes: >> >>>In 3.0 this was solved by vdi_healthy getting a struct sess passed >>>in, >> >>>I would like to discuss the possibility of adding a vrt_ctx parameter >>>(or simply the digest) to the vdi_healthy function in Varnish >>>4.0. Other suggestions would also be welcome. :) >> >>This runs into a very big question: >> >>Are backends (and should they be ?) visible on the request side at all ? > > > Sorry, that was probably too terse... > > > The question is probably better expressed this way ? > > Do the saint::health need access to req.* ? or bereq.* ? > > What will it do ? Make grace decisions on the client side or fetch > decisions on the backend side ?
The way I envisioned it is purely on the fetch side. So 'saintmode' in this case will be a tool that helps us avoid picking a backend for certain URLs. Unlike 3.0, it's not meant to be used for deciding whether or not to serve a graced object, and I think that's fine since 4.0 does "stale-while-revalidate" and serves grace candidates by default anyway. It would of course be nice to be able to avoid kicking off a fetch thread if we had that information at hand, but I don't see how we could do that without severely breaking the rules of client/fetch side separation. -- Dag Haavi Finstad Software Developer | Varnish Software AS Mobile: +47 476 64 134 We Make Websites Fly! _______________________________________________ varnish-dev mailing list [email protected] https://www.varnish-cache.org/lists/mailman/listinfo/varnish-dev
