My random thoughts

Dag-Erling Smørgrav des at
Sat Feb 11 21:23:10 CET 2006

"Poul-Henning Kamp" <phk at> writes:
> "Dag-Erling Smørgrav" <des at> writes:
> > Multiple cache layers may give rise to undesirable and possibly
> > unpredictable interaction (compare this to tunneling TCP/IP over TCP,
> > with both TCP layers battling each other's congestion control)
> I doubt it.  The front end Varnish fetches from the backend
> into its store and from there another thread will serve the
> users, so the two TCP connections are not interacting directly.

You took me a little too literally.  What I meant is that we may see
undesirable interaction between the two layers, for instance in the
area of expiry handling (what will the front layer think when the rear
layer sends it expired documents?).

> > Unfortunately, PGP is very slow, so it should only be used to
> > communicate with some kind of configuration server, not with the cache
> > itself.
> Absolutely.  My plan wast to have the "management process" do that.

Hmm, we might as well go right ahead and call it a FEP :)

(see if you didn't catch
the reference)

> > unlike regexps, globs can be evaluated very efficiently.
> But more efficiently still if compiled into C code.

I don't think so, but I may have overlooked something.

Dag-Erling Smørgrav
Senior Software Developer
Linpro AS -

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