On Sun, 19 Sep 2004, David Lang wrote:
assiming that the simplest method would cost ~$3000 to code I would make a wild guess that the ballpark figures would be
1. active/passive without automatic failover $3k
2. active/passive with automatic failover (limited to two nodes or withing a murder cluster) $4k
3. active/passive with updates pushed to the master $5k
4. #3 with auto failover (failover not limited to two nodes or a single murder cluster) $7k
5. active/active (limited to a single geographic location) $10k
6. active/active/active (no limits) $30k
in addition to automaticly re-merge things after a split-brin has happened would probably be another $5k
I think that you are missing a zero (or at least a fairly substantial multipler!) from 5. 1 -> 4 can be done without substantial changes to the Cyrus core code, and Ken would be able to use my code as a reference implementation, even if he wanted to recode everything from scratch. 5 and 6 would require a much more substantial redesign and I suspect quite a lot of trial and error as this is unexplored territory for IMAP servers.
-- David Carter Email: [EMAIL PROTECTED] University Computing Service, Phone: (01223) 334502 New Museums Site, Pembroke Street, Fax: (01223) 334679 Cambridge UK. CB2 3QH. --- Cyrus Home Page: http://asg.web.cmu.edu/cyrus Cyrus Wiki/FAQ: http://cyruswiki.andrew.cmu.edu List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
