[Asterisk-Users] Asterisk on 64bit ?

[Nicholas Bachmann]

Dr. Rich Murphey wrote:

>How do you balance the number of active connections per server?
>

[Rich, this deep in a tread, it's helpful to everybody if you post inline]

TCP load balancers can make "affinity tables" (or just "affinities" in 
Cisco parlance) that map clients outside the LBR to servers.  There is 
some logic to take clients out of the table after a timeout so that they 
can be evenly rebalanced later, and the result is a near-even 
distribution of clients between servers.   There is no need for the LBR 
to understand SIP or RTP, it only makes tables to say what clients use 
what server.  If the LBR detects a downed server, its clients are 
remapped to a new server when they make new requests.  On most units, 
administrators can also gracefully ween servers out of the pool for 
scheduled maintenance.  The downside of course, is cost.  ATI's Rapier 
24 L3 routers (which I use because I know they're comparatively cheap 
and have lots of good features) run about $100/port, plus a feature 
license for load balancing.  Soft load balancers also exist, such as the 
free Linux Virtual Server that somebody else pointed out.  LVS is 
capable of doing affinities, but I'd pay the $3-5k for a decent LBR 
before I trusted a $400 PC; the LBR does create a single point of 
failure, unless you've got an LBR that supports a fail-over balancer 
(which the ATI units do).

Nick