Is there any way to provide 100% uptime on SQL Server 2008 R2?
From my experience, the downtimes for the different replication methods are:
- Log Shipping: Lots (for DR only)
- Mirroring w. NLB: ~ 45 seconds
- Clustering: ~ 5-15 seconds
And all of these solutions involve all of the connections being dropped from the source, so if the downtime is too long or the app's gateway doesn't support reconnection in the middle of task, then you're out of luck.
The only way I can think to get around this is to abstract the clustering a level (by virtualising and then enabling VMWare FT. Yuck. Good luck getting this to work on a quad-socket, 32-core system anyway.).
Is there any other way of providing 100% uptime of SQL Server?