In message <[email protected]>, Geoff Simmons writes: >On 2/24/11 9:59 AM, Poul-Henning Kamp wrote: >> In message <[email protected]>, Geoff Simmons writes: >> >>> @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? >> >> Yes, I thought I had communicated that already: when ttl is set to <= zero, >> grace and conditional_timeout SHALL also be set to zero. > >You did indeed. So then my question is, is there a disadvantage to >allowing an object to be used for the IMS request if ttl and grace have >both elapsed, but conditional_timeout has not yet?
yes, we don't know why it was expired. Imagine a PHP error causing an object to be mis-rendered. This is discovered, the bug fixed, the object purged. Now, if you use the cached object for IMS, the backend is unlikely to know about the implications of the changed PHP file, and will just look at the timestamp and say "Sure, you can use that..." Expiry in Varnish is final, unless the user tells us otherwise. Similarly, we will not use a ban'ed object for grace or ims. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [email protected] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ varnish-dev mailing list [email protected] http://www.varnish-cache.org/lists/mailman/listinfo/varnish-dev
