[geeks] Remote Failover

[Sridhar Ayengar]

Bill Bradford wrote:
> On Tue, May 20, 2008 at 11:47:43AM -0400, Sridhar Ayengar wrote:
>> I'd like it to happen something like:
>> 1.	One of the web servers notices that another is down.
>> 2.	The web server that noticed the error sends a message to the DNS server 
>> updating the "www" CNAME to remove the downed machine.
>> 3.	The downed machine comes back up and notices that it is no longer
>> in the DNS round-robin so it sends a message to the DNS server to add
>> itself back into the "www" CNAME.
> 
> DNS round-robin is a really poor way to do failover/balancing, due to TTL
> and caching.  Why not use Ethernet load balancing, etc (LocalDirector and
> so forth)?

Because the machines are a thousand miles apart.  I'm not particularly 
concerned with balancing, really.  And I can always set the TTL really 
low for that one record, no?

Peace...  Sridhar