One of my customers asked me if we supported SQL Clusters and I couldn't answer because I have never used one.  Has anyone ran a StrataFrame .NET application on a SQL Clustered database?  What happens with the primary cluster fails, does it automatically switch seamlessly to the secondary sql server. Do you need to change connection strings?

Any assistance would be greatly appreciated.

Hi Tim,



I've never used clusters but its my understanding that applications don't have to take clustering into account - it 'just works' with auto failover should one node fail. That being said I presume there's a bound to be quite a bit of new stuff on the admin side to create and monitor the cluster.



IMHO clustering is only useful in a "can't stop for anything" environment in which case you also need to be sure to cluster the box the apps run on.



We have a factory system in which when the computer dies the factory stops. What we did is accept that a stopage of 10 / 15 minutes was acceptable if it only happens once or twice a year and then made sure we had a near real-time copy of the database by using transactional replication which, in practice, never seems to have a latency more than 5 seconds. This is with a transaction rate of around 10,000 new records per shift. Then, if needed, we could restart on another machine using the backup database.



RAID disks are, of course, the first line a defence in securing the database.



Cheers, Peter

Hi Tim,



This thread appeared in www.SQLServerCentral.com today - it may be useful to you: http://www.sqlservercentral.com/articles/Clustering/65994/



Cheers, Peter

Thanks Peter, I will check it out.

Typically, a stateful (vs. stateless) application will not be cluster "aware" and in a failover situation will get connection errors, but as soon as the failover is complete (10-30 seconds depending on server hardware, etc.) then users can re-connect without changing any connection information. In other words, the physical address does not change. I'm not sure if using SF enterprise server would make your client app more cluster aware or not...