[Serusers] Questions about ser

[Jan Janak]

On 25-07-2005 19:28, Andrei Pelinescu-Onciul wrote:
> On Jul 25, 2005 at 12:07, Michael Ulitskiy <mdu113 at acedsl.com> wrote:
> > On Monday 25 July 2005 08:21 am, Jan Janak wrote:
> > > > >   No, you don't need hundreds of children, usualy 16 is maximu what you
> > > > >   need. Newer ser versions contain connection pool, so each child will
> > > > >   open exactly one database connection and it will be reused across
> > > > >   modules.
> > > > 
> > > > What about processing that involves slow DNS queries? I thought this would
> > > > eat up available workers quite quickly and further processing will be blocked?
> > > > Please correct me if I'm wrong.
> > > 
> > >   You can install local (running on the same host as the proxy) DNS
> > >   cache that can also cache negative entries (those that do not exist or
> > >   cannot be looked up), such as dnsmasq. This way the slow query would
> > >   be performed once and subsequent queries will be answered from the
> > >   cache.
> > >   Moreover, kernel maintains a queue of incoming SIP requests and it
> > >   will continue receiving SIP messages even if all processes are
> > >   blocked. The kernel starts to drop incoming SIP messages once the
> > >   queue is full.
> > 
> > Well, I guess it's not a solution. It's a workaround at best. I'd vote for something
> > apache-like. I.e. master process monitoring the number of idle children and forking
> > additional as needed. Thanks anyway.
> 
> Why not start them all from the beginning? Is not like they will eat a
> lot of resources...
> 
> 
> > Also could you (or someone) give me a rough estimation on what is the optimal 
> > number of children to serve let's say 10k sip clients as registrar and proxy with 
> > moderately complex config file, but not involving DNS queries? INVITEs may involve
> > several database queries to a dedicated database server. I understand that the
> > question is rather vague, I'm just interested in a rough estimation and some 
> > real-world numbers people use.
> 
> Try it and if you can see packets in the socket buffers (netstat)
> increase the number of children.
> I would use 20-50 children. 

  This it to be on the extra-safe side. I was using 16 children on a
  similar system (in terms of number of subscribers) with DNS turned on.
   
     Jan.