Database Mirroring: Maximizing Availability Through Automation Robert L Davis

Who am I? DBA on the CAP Operations Team Worked as a database developer/administrator since 2000 Been at Microsoft for 2 ½ years as a vendor and now as an FTE Co-author of Pro SQL Server 2008 Database Mirroring (Oct. 2009) Blog: http://www.sqlservercentral.com/blogs/robert_davis

Automation How can automation help me maximize availability of my mirrored databases? When a controlled failover occurs, a short outage occurs. The longer it takes for the failover to occur, the longer your outage is. Manual intervention is prone to errors and missed steps. T-SQL never feels stress when others are panicking. You don’t need to be a Subject Matter Expert to run a script or procedure. Common pitfalls that you may potentially have to deal with can be built in to the scripts or procedures.

Demo Scenario Your principal server is on the verge of failing and needs a Windows hotfix installed immediately. Your supervisor wants you to fail over the mirrored databases. Since this is an unplanned, unauthorized downtime, you must do it as quickly as possible. Demo 1: There is no automation in place. You are not the SME for database mirroring. Your knowledge of how to fail over a database is limited to using the SSMS GUI. Demo 2: There is no automation in place. You are not the SME for database mirroring, but you are well read on the subject and eager to put what you know to work. Demo 3: You are the SME for database mirroring. You knew something like this would happen. You have planned for this, and you have put automation procedures in to place and have tested them during monthly patching, Service Pack upgrades, and other events.

Demo Scenario …… To make matters worse, your supervisor is standing in front of your desk repeatedly emphasizing how important it is to do it quickly and staring at you like he expects you to mess things up. And Tom, the new Jr. DBA they just hired, is standing just outside the doorway listening for you to mess things up so he can “save the day” and get the promotion that you are expecting to get.

Conclusion Without a doubt, the automated failover process is faster and accounted for potential problems after failover that the manual processes did not. In Demo 1, Tom “saved the day”. Your supervisor is happy … that Tom just happened to be in the right place at the right time. In Demo 2, Tom didn’t get to save the day during the failover, but he later identified why the application was failing and ended up the hero anyway. In Demo 3, your supervisor was delighted with how fast things went. He looked at Tom lurking in the doorway and barked at him to get back to work. You were the hero.

Database Mirroring: Maximizing Availability Through Automation Q&A

Database Mirroring: Maximizing Availability Through Automation Thank You! The PowerPoint slide-deck and the stored procedures will be posted on my blog this weekend. http://www.sqlservercentral.com/blogs/robert_davis