Re: Replication Advise

[Aaron Richton <richton@nbcs.rutgers.edu>]

On Tue, 10 May 2011, Ben Rockwood wrote:

>  I have a mirror-mode configuration between two nodes in a single data 
> center now.  I'd like to expand this to 2 additional data centers.  The 
> intent would be to have read-only HA pairs in each of the new data 
> centers that will continue to function even if the data center is cut 
> off from the primary pair.

I'm not clear as to what you're looking to install in your new locations. 
The wording ("read-only HA pairs") implies additional mirrormode 
installations, but I don't think that makes sense if you are specifying 
read-only capability. If your concern is additional read-only capacity 
then you should just be expanding your replica pool, nothing more. This is 
true regardless of whether you desire on-site or off-site read-only 
capacity.

Please see the diagram in the Admin Guide, section 18.3.4.1.1. Actually, 
if you're revisiting your architecture, rereading the entire chapter may 
be in order...