event engine library selection

Poul-Henning Kamp phk at phk.freebsd.dk
Tue Mar 14 11:03:23 CET 2006

DES and I talked a bit about which event library to select for
varnish long time ago and and I belive we have ISC's and Niels
Provos' in the pool.

As far as I can tell from inspection, the ISC code is "industry
strength" where the Provos code is more "engineering sample".

I'm quite worried that the multi-thread support in Provos library
consists of creating events, and then as quickly as possible move
them from the most recent engine to the one where they belong, that
doesn't sound very safe to me.

On the other hand, the Provos engine sounds like it is much more
performance focused than ISC's engine, and that must count heavily
for it as the acceptor/header-collector point is going to see
significant load.

If we decide on the Provos engine, we may have to spend time to fix up his
multi-thread support and hope he will accept the patches.

Comments ?


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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