[Asterisk-Users] Re: load balancing 20 asterisk servers

[Rich Adamson]

> >> The DNS approach does not handle single or multiple system failures,
> >> only very elementary load balancing over a lengthy period of time.
> >
> > Are you shure of that? I'm aware that the load criteria is trickier, 
> > but very possible.

Yes, very sure. Look at past posts relative to the Broadvoice.com problem
and you'll see one step in the recommended 'fix' was to install a
/etc/hosts entry in the customer's system. Once something like that
is done getting that admin to remove/change it is almost impossible.

> Operating systems and probably a lot of devices *cache* the results of 
> DNS lookups. That means removing A records won't do any good.

One can specify a short dns cache time within the primary dns, however
a substantial number of machines ignore the value.
 
> Short story: No matter what network service is being balanced, if you 
> want to guard against failure and against customers noticing that 
> failure use a real load balancing solution, DDNS is not suitable.

Agree with that 100%.