Numerous licensing changes were introduced in SQL Server 2012; the most significant was the move from socket-based licensing to core-based licensing for Enterprise Edition. One of the challenges that Microsoft faced with this change was providing a migration path for customers that previously used Server+CAL based licensing for Enterprise Edition prior to SQL Server 2012. Customers under Software Assurance can upgrade to SQL Server 2012 Enterprise Edition and still use Server+CAL licensing (also known as "grandfathering") but with a limitation to 20 logical processors, as documented in the SQL Server 2012 Licensing Guide.
SQL Server offers two methods of collecting diagnostic and troubleshooting data about the workload executed against the server: SQL Trace and Extended Events. Starting in SQL Server 2012, the Extended Events implementation provides comparable data collection capabilities to SQL Trace and can be used for comparisons of the overhead incurred by these two features. In this article we'll take a look at comparing the "observer overhead" that occurs when using SQL Trace and Extended Events in various configurations in order to determine the performance impact that data collection may have on our workload through the use of a replay workload capture and Distributed Replay.
SQL Server 2012 AlwaysOn Availability Groups require a database mirroring endpoint for each SQL Server instance that will be hosting an availability group replica and/or database mirroring session. This SQL Server instance endpoint is then shared by one or more availability group replicas and/or database mirroring sessions and is the mechanism for communication between the primary replica and the associated secondary replicas.
Depending on the data modification workloads on the primary replica, the availability group messaging throughput requirements can be non-trivial. This activity is also sensitive to traffic from concurrent non-availability group activity. If throughput is suffering due to degraded bandwidth and concurrent traffic, you may consider isolating the availability group traffic to its own dedicated network adapter for each SQL Server instance hosting an availability replica. This post will describe this process and also briefly describe what you might expect to see in a degraded throughput scenario.
As lots of you know already, Kevin Kline (blog|@KEKline) has joined us here at SQL Sentry. I've followed Kevin myself for a good while, so I'm really excited to have him here with us.
One of the first things Kevin asked of me was to list the top 5 technical issues we see while providing customer service for SQL Sentry. For our Client Services team, technical support is far more than just supporting our own software products or managing licenses. Everyone on the team is deeply trained in SQL Server, Windows and Microsoft .NET. In fact, in general, any member trained on our Client Services team should be able to walk into the role of a Windows sysadmin, SQL Server DBA or .NET Application Developer with very little adjustment effort.