-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Hello Poul-Henning,
I'd like to make sure that we have a common understanding about the grace and keep intervals for backend conditionals. In particular, IIUC an object that is still in grace can be a candidate for an IMS request. Shortly after VUG you wrote: > ttl=0, grace>0 > This is a special case, where the object is expired, but still > available for grace (you have to first set obj.ttl = 0 and then set > obj.grace to nonzero, as obj.ttl = 0 also clears obj.grace) > I think in this case it is a candidate, the admin clearly considers > the content valid enough to use in an emergency, so it should be > fair game for IMS also. So: if TTL has elapsed, but Varnish finds an object in grace, and decides as it does now to serve it from cache, then it does so; otherwise Varnish uses it to attempt the conditional request (if the object has the headers for it). That would mean that setting keep = 0 does *not* switch off backend conditionals, if grace is non-zero. keep = 0 just means that the interval in which IMS can take place is not extended any longer than grace. The only way to prevent backend conditionals altogether would be in VCL, by removing the IMS and INM headers from bereq. Is that what you hand in mind? That last part tripped me up, because I was testing with keep = 0, expecting IMS requests to be switched off, but they were happening anyway (which is why I thought I had a bug). It turns out that it was the objects in grace. I think it would be fine for Varnish to work that way (and it's nice to not have a bug for once), but it should be documented clearly, so that others are not as confused as I was. Best, Geoff - -- UPLEX Systemoptimierung Schwanenwik 24 22087 Hamburg http://uplex.de/ Mob: +49-176-63690917 -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.14 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQIcBAEBCAAGBQJNe6u+AAoJEOUwvh9pJNURS8QP/RnLLqUdAPBTDFkNjz2jEOY/ khCW37md+T5Lu8GkL5y6+ueX00AUDEzsWFNkzL6nmk525UyUURxCUWISYXKNTpeT lm8TDarzH1HHTuZHhZqJ0Z2Gzy/5dp7UevxzY6d53iN/mjQt/4x3hL4S/EiEngBX YvwDaKS5xlfEWlUZ4xI3X5s6hWTiK2GdkNwhAQwnLox43NwuU/yoCeuN+tMkYWhU GV/X65ueUCwJ9e/CtP6P7ij+Sk/eWUx3KSdMqKB9Oi914gI3CZFmpdV+WLdDe4SP dtJYuqgxiuwHEokRsdC6VjhnxoKXBUwo0QGNY9Gmi4rDo+LhM0qNxKiRnTeBvu4t Eyhwe4HpkESdbh8KvwMCnQzMmSC+zbIMnuTYQ6Y92B6/JI8HgWKDLt2DPObl0O1j W3mgoqJCz2NDN2tWFt/K9EN92upIYquISxEges24mMRZUXWyw9oIcnFT0ITW6Jlf ogXaJBF+cluILFQRO1ubv6XYEZF6qq0jM3Otav8pVtwTBWpFpRLN/qVVdGF1Fy5D E+SO+YOyHcmFuZwJSSlYpHEBZECPxTdIwOcxqfzyQB3bhEt+ANySE71PmWErKC98 h8hQrA6HEMSp4f1SjZO/zwiD7jIWpLtrVNahml+hdl5Tk2qrxqhcUD9xkG3RfGoi d76Zk2gi3AUqHPn8LbP2 =Dd9Q -----END PGP SIGNATURE----- _______________________________________________ varnish-dev mailing list [email protected] http://www.varnish-cache.org/lists/mailman/listinfo/varnish-dev
