Hi

We have a 2-node cluster running Enterprise x64 SQL 2005 on W2K3. We
wish to install additional instances to assist management. We intend
to expand to a 3-node A-A-P cluster. Currently the heartbeat is
running via a cross-over cable with the private network being
prioritised.for internal communication.

My initial question is what is the recommended method of configuring
the heartbeat when adding a 3rd (or or more) node. Presumably the
options are additional nics for direct connections; some kind of
dedicated switch or hub; a VLAN on existing switches; other. What are
the risks to the existing production setup, if making changes to the
private network and cluster network priorities?

Are there any good white papers on this?

Thanks.

Steve

Good news is that as long as the public network is working AND enabled for
cluster communications, you can tinker with the private network without
problems.

I would use a small dedicated switch to connect the nodes for heartbeat.
Heartbeat communications do not take a lot of bandwidth but do need to be
low latency.

As with any change, I would test it on a lab setup first and only deploy it
during a maintenance window.

--
Geoff N. Hiten
Principal SQL Infrastructure Consultant
Microsoft SQL Server MVP


"Steve" <elstevester (AT) googlemail (DOT) com> wrote

On 24 Feb, 16:06, "Geoff N. Hiten" <SQLCrafts... (AT) gmail (DOT) com> wrote:
Geoff

Thanks for the quick response. That's really helpful.

If we can't find a dedicated switch for this, would you suggest
setting up a VLAN via our existing switch infrasturcture? and do you
know of any White Papers on the general topic of scaling out clusters?

Thanks again for your quick reply.

Steve

A VLAN is acceptable, but it does introduce a single point of failure, the
switch.

Whetever you do, do not ever team the heartbeat NICs. Teaming can cause
latency to exceed the timeout threshold, resulting in a false "node down"
detection. Not good.

BOL is your best starting point on how to expand a SQL Cluster.

--
Geoff N. Hiten
Principal SQL Infrastructure Consultant
Microsoft SQL Server MVP


"Steve" <elstevester (AT) googlemail (DOT) com> wrote