Varnish 3.1 becoming 4.0 instead (?)

Poul-Henning Kamp phk at
Fri Dec 9 09:48:57 CET 2011

In message <87ty5bmfsv.fsf at>, Tollef Fog Heen writes

>As long as you can detect whether a 503 is internally generated or not,
>that's fine.

That is an interesting idea, but why would that be important ?

>I don't think the 3.1 vs 4.0 naming is particularly important, but I
>know you feel much stronger about that than I do.

I think we owe the users to clearly mark when we muck about with
VCL syntax.  If consensus is that 3.1 is sufficient warning, then
fine by me.

>>         Eventually sess->ws should only exist when sessions do not
>>         wait, and then worker->ws can then be eliminated and sess->ws
>> 	contain both req.* and resp.*  (Hopefully in 4.0)
>Won't sess->ws always exist (and probably be where most vmods will store
>their data) or do you actually mean what you wrote? 

I usually mean what I write, but I may not have thought it through before
I wrote it :-)

My reasoning for the above is that large sites have very high numbers
of sessions waiting to see if the client will send more requests and
we need to reduce the memory pressure of that.

This is not a trivial change by any means, amongst other things a trivial
implementations opens several DoS vulnerabilities, so unless I get hit
by a really fast inspiratron, this will be somewhere past 4.0

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.

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