-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 On 2/21/11 11:02 PM, Artur Bergman wrote: > > On Feb 21, 2011, at 10:07 AM, Geoff Simmons wrote: > >>> >>> ttl=0, grace=0 >>> This is a clear cut expiry, but we may still catch it before the >>> grim reaper does, we should explicity make sure we do not. >> >> OK, we don't have anything to check for this case, so in our current >> code it might in fact pick up such an object. All right, then we'll >> explicitly rule this out. > > Why? > > I might want to force a IMS to the backend without having ttl or > grace. You can set the conditional timeout to 0 if you really want it gone.
My understanding of phk's point here is that setting both TTL and grace to 0 is a way of deciding in VCL to remove an object from the cache. Such an object will be evicted the next time the heap is re-organized. If you set obj.ttl = 0, then obj.grace is implicitly also set to 0, because this is expected to make the object no longer cacheable. If you don't want that, then you have to explicitly set a non-zero obj.grace. Setting obj.ttl = 0 is the basis for the sample VCL code in the Wiki for implementing a PURGE method. @phk: If we also implicitly set obj.conditional_timeout = 0 when obj.ttl is set to 0, wouldn't existing VCL continue to do what people expect? I think Sky has a point here, if conditional_timeout > 0 while TTL and grace are 0, it would mean that an object shouldn't be used for grace (another object is busy or the backend is sick), but could be used for IMS requests. If we're not breaking everyone's VCL, why not make that an option? 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/ iQIcBAEBCAAGBQJNZXjNAAoJEOUwvh9pJNURHyoP/j7gOtgtd1r2BjjI7yKjI1Xj wpROBavXMQfHaLQLHnFWFMz9ceUsBgkRmg+jydl8K/WA8t/zPPVs8vT0wYUQuomg ZmndPwYSsEKFwTJ4mhreHJLTC17bGUy7Ied0bzs80YmSD5CDR19PVig4FT/U7Tew DfcNWe/6ZPiv4B6WKO5LBvduL3zCqzLVH2IMKrmm5UIuvWJigPfl//SREAcpefiT HdAA4iRCbIcnt314pAnxG9uHHtXG++S1PM2rEXCG6gvvXjsEvTjY0EHvqsFadotZ 3stELcKAB2jsoAdNpyB2swxy3AOVryLUVIHRWnY/ZA6IUiHXItg85KlSSO26RudT gLj8k78N89gkTCRe3Gp1nvaE8p5SwerLmwi6119Sdfpj/IelH1JZKBSfNpzH2Zbm A5VNU9uvDzScSWw4WDyVVOlB7l0k40q0Uhv/n0D5X1JvwaXojunPFPp96JACRmDD 6OGYwoLERz+sSiBlSjOc3cB5kru0ascRx0BqjtyaVACGWTL71bITCmW/gFjCkZAg Bk0Wcfk6YLdQnLGPnacnvHN9MsZp5ecoMUDW9a5/0xMhj3PLfvtLxQMk388zEsIz 6b6jMqN6xHmxPXKrqiZPO8d+maVVMVlgZbBnXZsoUYl4UCN7JK6cqm8mVTgkwmDc 9M6HgRRiQ6EC8rCfGJVy =syd/ -----END PGP SIGNATURE----- _______________________________________________ varnish-dev mailing list [email protected] http://www.varnish-cache.org/lists/mailman/listinfo/varnish-dev
