[Asterisk-Users] Asterisk, enterprise edition (New subject)

[Nick Bachmann]

> On Sun, 2004-01-04 at 12:53, Nick Bachmann wrote:
>> Yes, I've played with it a bit.  It's pretty simplistic... the
>> clustering just keeps several servers in sync with each other.  I
>> suppose that would be easy to do with Asterisk, especially if
>> configuration data was stored in a RDBMS that could do replication.
>> Even now, setting up a copy/reload routine isn't difficult.
>
> A database doesn't make this easier. I would suggest you look into a
> revision control system and the ability to register
> applications/scripts to be run on check in of changes. Your benefit
> here is a quick roll out on hardware failure, plus roll back. You
> probably have seen people doing mailings based on CVS check ins, you
> could have those trigger a script on the clients that pulled fresh
> copies and did a reload. Fairly simple over all.

Yes, agree that CVS works well for this (that's how I manage my stuff).  I
like a RDBMSs for this kind of work, though, because the replication works
well and they are much faster than text files when you've got lots of
data.  Rolling back transactions is also pretty simple with most
databases, but I agree CVS is easier in this regard.
>> It also seems that if you had a load balancer set up in front of your
>> * servers to balance the call requests, you'd have enough clustering
>> to keep one failure from taking down the whole system. Since the load
>> balancer keeps an affinity table (and monitors to make sure the
>> servers aren't going down) all VoIP connections could end up at the
>> same * box once they had been allocated, unless a server goes down, in
>> which case the call probably gets dropped. Any planned downtime could
>> be made without any disruptions, since you could stop the load
>> balancer from allocating any more connections to the * box and use
>> 'stop when convenient' to wait for all current calls to end.
>
> The problem here is that you do have a single point of failure, the
> load balancer. It would be better to have multiple machines that you

That's why you buy a load balancer with its own redundancy :-).  The
Allied Telesyn SB series, for example, have two system controllers.  Cisco
stuff is probably similar.  The ATI stuff says about 30 seconds of
downtime when one SC fails, I would guess Cisco delivers less.
> selectively placed as primary and backup in your VoIP phones. It isn't
> true load balancing, but it does allow you only loose a specific amount
> of calls in progress at any time if a machine fails. Calls could then
> be picked up and restarted via the other machine. This would give fault
> tolerance, and would give the impression of having 5 9's as long as the
> failures are sufficiently spaced out.

I remind you that close only counts in horseshoes, hand grenades, and
nuclear weapons, and not with my users' uptime :-).
Nick