Implement Cyrus IMAPD in High Load Enviromment

[Robert Banz]

With my ever-growing experience with these things, I'm tending to  
think that application-level HA solutions are a much more robust way  
of dealing with the potential failure modes of hardware or software.

While this doesn't mean you shouldn't buy reasonably robust hardware  
(not the cheapest thing that falls off the truck), what it does is  
mean is that you should probably spend that extra money you would have  
spent on that redundant storage system and hot-plug-gable whatsit with  
replicating your server environment and allowing application-level  
replication such as Cyrus offers to do the rest.

This does mean that we need to lean on software "vendors", be it  
people we pay or ourselves to create applications that provide for  
application-layer high availability. However, in the long run it IS a  
much more robust solution, and covers a much larger number of failure  
domains for the time and money spent than throwing money and effort at  
covering the handful of failure-domains that comprise a hardware  
system -- since that really is an infinite money pit.

These "quality" enterprise software solutions that we're sold today  
that rely on "fault tolerant" hardware, instead of being "fault  
tolerant" themselves are not acceptable.

-rob