[Devel] discussion of roadmap for 1.3

["C. Bergström"]

Klaus Darilion wrote:
> I would like to see more feature for security/stability:
> - do not block during establishing new TCP/TLS connections
> - do not try to establish TCP/TLS to clients behind NAT
> - possibility to drop final response if there is no matching transaction
> - do not block during DNS lookup
>
> I also thought how to make openser more responsive during high
> load/blocking - e.g. openser blocks because of DNS or DB problems.
> Then we get retransmissions, the input queues get full and openser
> collapses. I first idea would be a dedicated worked thread which
> handles this overload traffic - and only this overload traffic using a
> dedicated route, e.g.
>
> overload_route {
>     append_to_reply("Retry-After: 300");
>     sl_send_reply("500","Server busy");
>     exit;
> }
>
> If all the worker threads are blocked for some time (e.g. >100 ms),
> then the scheduler start giving the incoming requests to the overload
> thread until the worker threads become idle again.
>
> Any comments?
Hi Klaus,

Excellant ideas.. For postgres I can possibly help (re)write so the db
doesn't block on connections or queries..  My schedule between the 16th
until the course in Paris is entirely dedicated to voip code so I may be
able to come up with some (if) needed patches then.

Other ideas which could really make a difference with the db side of
things is doing some smart caching on frequent lookups with data that
doesn't need to be invalidated often.  Pretty much anything that fits
that profile can be put in a hashtable with an expiry.  (Not sure if we
are doing this already?)

I also have some completely unresearched ideas about packet marking to
help tie in QoS with routers/switches.

Thanks

C.