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From Igor Galić <i.ga...@brainsware.org>
Subject Re: 3.0, the 2011 thread.
Date Sat, 18 Jun 2011 23:37:04 GMT


----- Original Message -----
> 2011/6/18 Igor Galić <i.galic@brainsware.org>:
> >
> >
> > ----- Original Message -----
> >> On Friday 17 June 2011, Graham Leggett wrote:
> >> > We used openssl to make our non blocking event driven stuff
> >> > work,
> >> > and it works really well (once you've properly handled
> >> > SSL_ERROR_WANT_READ and SSL_ERROR_WANT_WRITE). There is no
> >> > reason
> >> > I can see that would stop us using openssl to be async in httpd,
> >> > we just need to refactor the mod_ssl code to actually do it.
> >>
> >> Someone (Paul?) once told me that openssl is not very good when it
> >> comes to async access to the session cache (which could need
> >> network
> >> io if using memcached), CRLs (which I could imagine to reside in
> >> LDAP)
> >> and similar things. But this would have to be evaluated.
> >>
> >> > The tricky part with event driven code is the really bad support
> >> > for   event driven file access. We used libev as our core event
> >> > loop, which does a significant amount of work to make files and
> >> > sockets work the same way in the event loop as best it can in a
> >> > portable way. Don't know of any other event loop that does this.
> >> > It's difficult trying to do the event driven thing if you
> >> > intersperse event driven socket handling with blocking file
> >> > handling, you end up with many requests blocked by an unrelated
> >> > system call.
> >>
> >> Yes, I guess we would need a pool of lightweight worker threads
> >> that
> >> does the file io (especially sendfile). Those threads would
> >> probably
> >> get by with very small stack sizes and use little resources. If
> >> the
> >> event library we choose already has this built in, we can of
> >> course
> >> use that, too.
> >
> > This kind of reminds me of the architecture of Apache Traffic
> > Server
> > see http://www.slideshare.net/zwoop/rit-2011-ats
> >
> 
> Yes, ATS is the right model I think, but I don't think the... C++isms
> and general bagage that comes along with it are ideal for httpd
> though?

I was merely referring to the architecture,
not its implementation :)

i

-- 
Igor Galić

Tel: +43 (0) 664 886 22 883
Mail: i.galic@brainsware.org
URL: http://brainsware.org/

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