On Sep 16, 2005, at 11:07 AM, Jeff wrote:
> There shouldn't be a problem if:
> server A is ver 4.0.x
> server B is ver 4.1.x
> should there?
There will totally by a problem here... The 4.1 server will take the
4.0 feed without issue. The 4.1 server however puts all sorts of
information into the binary log which isn't in the original query,
like what sort of collation to use, and which character set it uses
and so on... 4.0 doesn't understand such commands and lots of things
break in this situation.
As a side note we deploy servers in pairs, with circular replication.
We did three and four server circles, but it gets messy if
replication stops somewhere, the data becomes unpredictably
inconsistent (assuming all the servers in the circle are getting
production updates). Now we do simple two way replication between a
pair, and we hang a third server off the pair somewhere just
reading... the third server we use for backups, data dumps, reports
and other non production issues. Essentially it is something like A<-
>B->C, where A and B have two way replication and C is used for
backups/reports etc... anything that changes the data happens on A or B.
We do some other black magic to manage the replication on C so it's
perpetually behind the master servers by between 15 minutes and 2
hours... that way if we have a stupid operator error or some other
data corrupting event we can stop replication on the backup server
before it executes and start from there rather than having to go back
to yesterdays backup or something.
Best Regards, Bruce