Just one slight clarification to Mark's post:

"If one of your servers has all of the HADR primary databases
on one server, and all the standby databases on the other server, then
you only need a 1 CPU license of ESE on the standby (regardless of the
actual number of CPU's on the standby)."

Actually, this is true as long as you are not using the entire standby
server for ANY production DB2 workload ... i.e. if it is exclusively a
standby server.

Larry Edelstein

Mark A wrote:
> RayRay wrote:
>
>>I was hoping I might be able to get an answer regarding DB2 and HADR.
>>Let me preface this by saying that I know very little about networking
>>and I'm not familiar with the HADR product or clustering. But, I've
>>been asked to research a couple issues for a client.
>>
>>They are thinking about implementing HADR. They have DB2 production
>>databases running on more than one box.
>>
>>Does a liscense for HADR need to be purchased for each production box
>>running DB2, or does the HADR software come standard as long as you are
>>running the Enterprise Edition of DB2 on each box in question?
>>
>>What would be a recommended architecture for a company that currently
>>has multiple databases on a couple of production boxes (I know there
>>are a lot of variables that come into play, but I'm trying to get a
>>simplistic picture)? Cluster the production boxes together and cluster
>>the backup (or standby) boxes together? I assume DB2 and HADR have to
>>be available on each box (production or standby) in question.
>>
>>Please don't get too technical if you respond. Any clarification would
>>be greatly appreciated.
>>
>>Thanks for your time,
>>
>>Ray
>
>
> DB2 ESE comes with an included license for HADR. If you have DB2 WSE or
> DB2 Express, you must purchase HADR separately to be licensed on each
> machine. If one of your servers has all of the HADR primary databases
> on one server, and all the standby databases on the other server, then
> you only need a 1 CPU license of ESE on the standby (regardless of the
> actual number of CPU's on the standby). This does not prevent you from
> temporarily switching primary databases to the standby server because
> of some problem with the primary or because of maintenance being done
> on the primary.
>
> However, instead of having all the primary databases on one server, and
> all the standby databases on the second server, you can have half the
> databases as primary on server 1 and half the databases as primary on
> server 2. HADR works on database level.
>
> If you have a lot of updates, inserts, and deletes on these databases,
> you may want to set up a private Ethernet between the 2 servers to
> handle HADR replication traffic, while all the application traffic
> comes in through the public Ethernet. If the 2 servers are close enough
> together, you can use a simple crossover cable for the private
> Ethernet, or set it up on a switch/router/hub if it is bit further away.
>