[sr-dev] new feature: per-socket number of workers

[Daniel-Constantin Mierla]

Hello,

the master branch has a new feature that allow setting number of worker 
processes to handle received traffic per listen socket.

So far there were global parameters that were applied to all sockets 
(e.g., 'children' value set the number of workers for all udp sockets). 
So far each UDP and SCTP socket had its own pool of workers (e.g., 
children=4 and 2 udp sockets resulted in 8 processes), while for tcp and 
tls was a single pool of workers (e.g., having children (or 
tcp_children) set 8, resulted in 8 processes no matter how many tcp/tls 
sockets).

The new features is based on using a new config parameter, named 
"socket_workers", before a "listen" parameter. The value of 
socket_workers will overwrite the value of *children parameter. For UDP 
and SCTP will result in creating a number of "socket_workers" processes. 
For TCP and TLS will add an extra set of "socket_workers" processes, 
that will handle traffic only on those specific sockets.

The value of "socket_workers" is reset with the next listen socket 
added. If "socket_workers" is not set, the value of "*children" 
parameter is used in backward compatible fashion.

Some typical scenarios where this feature may become handy:
- set a lower number for loopback or internal/replication sockets, as 
the traffic there is low (e.g, maybe for keepalive monitoring on 
loopback, or it is only REGISTER requests replication done over the 
replication sockets)
- set a dedicated group of tcp/tls workers for handling http/xmlrpc/xcap 
traffic - handling such traffic may be time consuming, in this way you 
avoid delays on routing SIP over tcp/tls
- fine tune the number of over all forked processes by a SIP server 
instance, thus controlling better the resources used from the physical 
server (e.g., overall private memory used by sip server is a matter of 
how many forked processes are there)

You can see details about the new parameter and examples on the wiki page:

    * http://www.kamailio.org/wiki/cookbooks/devel/core?&#socket_workers

Cheers,
Daniel

-- 
Daniel-Constantin Mierla -- http://www.asipto.com
http://linkedin.com/in/miconda -- http://twitter.com/miconda