Cyrus IMAP and MySQL mailboxes (Building load-balancing cluster)

[Robert Banz]

On Nov 20, 2006, at 06:34, Marcelo Maraboli wrote:

> Andrew
>
> thanks for the "scalable" Cyrus solutions, but I´m wondering
> what can be done for Availability solutions ??
>
> What if an IMAP server dies (we had this happen) ??
>
> We have a Solaris Server with a RAID5 disk array storing the
> MBOX, but the server died....so downtime was a bit huge..
>
> I wan to build a 100% available IMAP solution...is there any?

Even with a couple dumptrucks full of money, nobody could pull off 100%.

...but you can get really close.

Consider housing your storage on *two* individual storage devices,  
potentially in different buildings.  Mirror between them at the host  
level (cheap), or, through multiple redundant storage virtualizers  
(pricey)

Set up an active/passive cluster.  Relatively "easy" to do nowadays.   
Or go the clustered FS route (but then you'd probably need the  
storage virtualizers)

Basically, for each '9' after 99% uptime, expect to double your cost  
and complexity of implementation.

-rob