Weird situation with unexpected 206 from the backend, hit-for-pass and default_ttl
tom+varnish at ankh.fr.eu.org
Mon Mar 1 12:58:52 CET 2010
Le lundi 01 mars 2010 à 10:32, d'après
Tollef Fog Heen <tfheen at varnish-software.com> :
> We generally try to avoid guessing in the C code, so I think this should
> be left for VCL.
I tried the "unexpected 206" with -trunk (r4596), and it acts just as I
wanted! So I guess this was already fixed in the C code. Or maybe just a
side effect of some other fixes?
> What happens if you set obj.cacheable to true and ttl to 1s if the
> response is a 206? Does that work?
I will give it a try with 2.0.6 and report the result.
However, the VCL trick that didn't work for me is supposed to work
according to the FAQ:
Also, I found some more interestings things about the hit-for-pass TTL,
be it in 2.0.6 or in -trunk, it appears from my various tests that it is
computed as the maximum between default_ttl and the "RFC" TTL from the
obj/beresp headers. My default_ttl was 86400...
Is this a known feature? I didn't see any explanation about this on the
> | - I also tried to purge the hit-for-pass culprit with the CLI (purge
> | req.host == the.host && req.url == /the/url), but it didn't work
> | (the object was still there after). Any idea how to purge such
> | objects ? Is this a bug ?
> According to phk on IRC, this should work and it not working is a bug.
I'm confused about this one, as it definitely worked for me on a new
test yesterday. I think we can put this one on human error on my part
for the moment (and I will probably do some more tests just to be sure).
Or maybe it as something to do with default_ttl (since I put it back to
its 120s default value before doing the test that worked)?
> If you have a chance to reproduce this in a test environment with both
> 2.0.6 and trunk, that'd be appreciated.
Yes, I now have a test environment where I can reproduce all this
(that's how I noticed that -trunk behaves better). Will do the
purge/default_ttl test again. If you want another specific test, just
Thomas Parmelan -+- Thomas.Parmelan at free.fr -+- tom at ankh.fr.EU.org
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