David Lang
Mon, 20 Sep 2004 10:25:54 -0700
On Mon, 20 Sep 2004, David Carter wrote:
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 Lang
-- 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
-- There are two ways of constructing a software design. One way is to make it so simple that there are obviously no deficiencies. And the other way is to make it so complicated that there are no obvious deficiencies. -- C.A.R. Hoare --- 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