[systemd-devel] Thoughts on adapting daemons to use socket activation

[Alexander E. Patrakov]

2012/8/21 Lennart Poettering <lennart at poettering.net>:
> On Sat, 18.08.12 16:04, David Strauss (david at davidstrauss.net) wrote:
>> Additionally, socket activation could get rather interesting
>> capability if there were a middle-ground between single process per
>> connection and one process for all connections. Frameworks like
>> Twisted Python and node.js have built their own wrappers to do this in
>> various kludgy ways that involve a master process opening the main
>> socket and then passing file descriptors or other structures into the
>> fork()ed processes or using separate "load balancers" to spread the
>> requests out. This might be totally out of scope for systemd, though.
>
> Hmm, so this would mean systemd would spawn multiple instances of a
> service binary, but pass all of them the listening socket? Interesting
> idea. We could probably do that, but we couldn't dynamically know how
> many worker processes to spawn, since we wouldn't know how much entries
> are queued unprocesse on the socket... Or maybe, there is an
> ioctl/sockopt for that? Definitely an interesting idea...

No need to configure this dynamically. This is supposed to be an
option configured statically by the sysadmin via a configuration file
(a service file?), just like the ServerLimit and MaxClients apache2
config directives. And the whole things looks very much like apache2
preform MPM.

-- 
Alexander E. Patrakov