I was recently asked a question, while fixing a cluster connectivity issue, about how the cluster resource dll knows on which port to connect to SQL Server. It’s not a very exciting answer, which is, “It doesn’t.”. After some days passed I was thinking about the question and answer as though the response I had […]
I see many questions, and have been on the receiving end of many myself, about out of support items and removing them from their SQL Server servers. One of these items is the SQL Server Native Client, aka SNAC, aka SQLNCLI, and I’m sure many others. I remember investigating the connections a very long time […]
You’ve Asked, It’s Now Here! The largest complaint, by far, for Availability Groups (AG) has been that system databases could not be part of the AG. This is how mirroring worked, and AGs were an evolution of mirroring, solving many of the problems that mirroring had (although mirroring solved many of the problems log shipping […]
Many DBAs haven’t had the experience of using database mirroring, since it was deprecated in 2012 when availability groups were released, and so there’s a lot of history that ends up being lost. We’re going to dive into some of that history and how it could affect your availability group! Update: You can get rid […]
Initially I thought to myself, “this is the most misunderstood wait type that exists in the HA space for SQL Server”, then I realized maybe this isn’t the case… So, I pondered over this question, “is it truly misunderstood?” and came to the (possibly incorrect) realization that it is quite accurate in the general SQL […]
One of the most common issues I look at from day to day is some variation of the question. “Why did it take a long time for my AG/Database to failover?”. There are many different meanings for this innocuously simple looking statement, for example was it that the failover time was long or was it […]
Departure Hopefully, you’re not finding this entry because you’re scouring the web for what reverting means while your production server is in this state… but chances are, that’s the case. Initiation What is reverting? How did I get here? Is this real life? All great questions. Each time a secondary replica connects to the primary, […]
I tend to be involved in many HA related issues, as is the nature of my current work agreement. The interesting part is that roughly 85% of all the “HA” issues are performance issues (with 10-12% being config issues and the last 3-5% being truly HA issues). Whether this is an FCI, AG, Replication, some […]
I Think My Knee Hurts, I Just Can’t Prove It Hopefully, you really do know if your knee hurts or not… it’d be odd if you weren’t sure. Regardless, this isn’t about knees but networks and specifically dealing with SQL Server Always On. I’m going to start out by stating that there are many improvements […]
On, Off, On, Off, On… I see this more often than I’d like to, so count this as your PSA (public safety announcement) when using VM level backup software, SQL Server, and even worse when you add in AlwayOn (FCI or AG). You might be familiar with these symptoms which may include: Unresponsive VMs Lease […]
