Re: Version blues
Date: Wed, 10 Jun 2009 19:33:21 -0500
"Serge Rielau" <srielau_at_ca.ibm.com> wrote in message
> Bob Jones wrote:
>> For high availability, "shared nothing" is a no no. Plus Gridscale is not
>> from IBM so you have to deal with 2 vendors.
> Where did I mention shared nothing?
GridScale IS a "share nothing" approach. Each instance in the cluster has it's own database.
> The relationship between IBM and xkoto is pretty tight. They are literally
> only a subway token away
Regardless of how tight the relationship is, GridScale runs outside of DB2 and is licensed separately. They are likely deployed in separate tiers as well.
> xKoto basically drives two (or more) replicas of the database.
> (similar to a RAC or Dataguard assuming you have true HA on your disk).
A single update will need to be applied on each cluster node to keep data in sync. That's more similar to replication not RAC.
> HADR (somewhat similar to Dataguard) gives you HA with few seconds
> failover time and near zero extra admin skills needed. That's used for
> most SAP systems on DB2.
Again, that is not RAC. Received on Wed Jun 10 2009 - 19:33:21 CDT