[asterisk-users] High Availability with Asterisk
asterisk at a-domani.nl
Sun Mar 9 15:16:10 CDT 2014
On Sat, 2014-03-08 at 20:27 +0000, adamk at 3a.hu wrote:
> My approach (in theory only, so please correct me if I'm wrong) would be
> to run asterisk on multiple boxes (one each). A dedicated monitoring
> box (nagios? custom scripts?) would perform frequent checks against the
> boxes (one of my previous projects one asterisk was using call files to
> demonstrate its health to another one).
> If a box fails, I would simply redirect/reroute its traffic to another
> one, using network solutions. Such as shutting down the production
> interface of a suspectedly failed asterisk box, having an idle one pick
> up its IP address, or using load balancing / routing / NAT to redirect
> the client's traffic to a standby box.
> My approach is based on the experience that linux based HA tools are
> often not free, or don't scale well, or engineered to circumvent an
> error in a slower manner (eg. booting a second VM takes too much time).
> However in the network world, there are well known protocols that were
> designed to take over in a matter of miliseconds.
> I do understand that this would not provide 'session' data, so failing
> over to a different box would mean the need to re-register, could cause
> calls to drop etc. This might be unacceptable for you. As I said in
> the beginning, I haven't been building such systems, in my experience a
> dropped call is not that big of a deal, if it happens because the
> network cuts over to a different box. This could be handled with a pair
> of frontend load balancers, where the number of asterisk boxes can be
> hope this helps
Don't confuse "high availability" with "load balancing", as these two
are not related. These two have totally different objectives and are
achieved in different ways.
Either/both of them can very well be achieved with opensource tools.
Even with commercial software is maintaining call when a intermediate
PABX breaks down nearly impossible
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