On Sat, Mar 06, 2004 at 01:39:28PM +0000, Silvana Di Martino wrote:
> a slave replica of your main database server. Should you have any problem
> with the main server, just switch the IP addresses of the master and slave
> servers and you are up and running again. The switching takes a few
> milliseconds and can even be performed automatically by a few specific
> programs (look for "fault-tolerant linux systems" with google). While your
And what do you do about the records which made it to the master
database but which haven't been applied on the slave yet?
Asynchronous replication with automatic failover is _dangerous_,
because you can strand records. Many commercial systems do this with
what they describe as conflict-management; in truth, this usually
amounts to marking _both_ records as suspect and letting the DBA
decide what to do.
I'm not saying that master-slave systems are a bad idea, but you'd
better be aware of what you're exposing yourself to before
considering such hot-failover cases.
A
--
Andrew Sullivan | ajs@crankycanuck.ca