Failover Clusters

[Mike.Sheen]

I recently visited a customer who expressed their need to as little as possible downtime in the event of a disaster.

They mentioned that if their SQL server did fail during business hours, it was important to be able to continue operating as soon as possible.

I mentioned the ability of SQL Server to be configured in a failover cluster, and floated the idea. They seemed interested, despite the obvious costs of an additional server and possibly SQL licence.

Now (I'm being lazy here), what do you need to setup a failover cluster - what edition of Windows Server and SQL Server do you need ?

Anyone got any experience with this ? You can post here, or if more appropriate PM me and I can connect you with the JSP managing the site.

[jiwameister]

Hi Mike,

Failover Clustering is defintely one way to go, but i think you will find it needs 2003 server enterprise edition. I do know that SQL Server 2005 Standard edition can work in a maximum of a 2 node cluster, however you have to consider the hardware requirements as well. Essentially you would need to run all of this on identical hardware, and have a common storage device between the servers (SAN etc). SQL 2005 automatically deals with failover of just about every sql service (including jobs, notification, reporting services etc).

Benefit of going down this track is that its relatively transparent from a user's perspective - but very hard to manage (and setup in the first place). Imagine trying to do software patches on this type of platform.. you need to follow very specific process to make this work.

In the customers requirement you mentioned above, I would probably recommend looking at database mirroring. This involves shipping the sql logs to a remote server (but needs another sql server as the "Witness"). The idea behind this is that the remote server is a mirror of the first, but the failover would not be automatic - just have to repoint clients to new server in event of failure. A lot less cost involved in this, and much easier to manage.

No special editions of SQL or Windows server needed also.

[Mike.Sheen]

I would probably recommend looking at database mirroring.

Yeah - someone else has pointed me towards that also - looks like a better fit than failover clusters.

Thanks!