On Sat, 2005-02-05 at 15:03, Jan Wieck wrote:
> On 2/4/2005 5:56 AM, Mike Nolan wrote:
>
> >> If you have so much update load that one server cannot accomodate that
> >> load, then you should wonder why you'd expect that causing every one
> >> of these updates to be applied to (say) 3 servers would "diminish"
> >> this burden.
> >
> > The update/query load isn't the real issue here, it's that these two
> > servers will be 800 miles apart and there are some advantages in having
> > each office connect to its local database rather than having one of
> > them connect to the remote master.
>
> You do realize that any multimaster replication system, that is designed
> to avoind complex business process structure based conflict resolution
> mechanisms, necessarily has to be based on 2 phase commit or similar? So
> your global write transaction throughput will be limited by the latency
> of your WAN, no matter what bandwidth you have. And as per RFC 1925: No
> matter how hard you push and no matter what the priority, you can't
> increase the speed of light.
>
I think the advantage Mike is looking for is to not have his READ
traffic have to travel 1600 miles for the remote office. If the read's
outnumber the writes by enough, he might have something to gain.
Mike, I've yet to see a thorough review of daffodil replicator but it
may be able to help get you to a little closer to what your looking for.
If you have time please check it out and see if it can be of any help,
I'm sure many of us would be interested in hearing some feedback on it.
http://www.daffodildb.com/dbreplicator.html
Robert Treat
--
Build A Brighter Lamp :: Linux Apache {middleware} PostgreSQL
