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.