Re: Parallel databases?

On Sat, 15 Apr 2000, Colin Smith wrote:

> On Fri, 14 Apr 2000, A James Lewis wrote:
>
> >
> > Does anyone have any suggestions for a way to keep 2 databases in sync?
> >
> > Ideally updates need to be made to both... this can't be too uncommon a
> > requirement..... any kind of HA would need it....

I've had a closer look at drbd. The home site is:
http://www.complang.tuwien.ac.at/reisner/drbd/

It will replicate the blocks on a device out to backup servers. If the
primary system fails the backup can take over. It doesn't do any
distributed locking so it's strictly a failover service at the moment.

It also looks like a real performance killer which is pretty much what
you'd expect with each block being sent over the LAN as well as to disk.
Definitely a case for a very high bandwidth low latency network (SCI, SP
switch) 100Mbit/1Gbit dedicated might be acceptable though.

--
|Colin Smith:  Colin.Smith@yelm.freeserve.co.uk  |   Windows 2000    |
|Linux: Delivers on the promises Microsoft make. |        AKA        |
|             http://www.linux.org/              |    The W2K Bug    |