Troubleshooting SQL Server Slowness using SQLDiag & SQLNexus

Luckily, two of the internal Microsoft tools used in order to diagnose slowdowns is also available for the publics use. These tools are SQLDiag (previously PSSDiag), and SQL Nexus. SQLDiag (short for SQL Diagnostics) monitors all aspects of the system that SQL Server is running on and generates all output needed in order to determine the bottleneck. The difficult challenge that follows is how to interpret that data. This is where SQL Nexus comes in.

SQL Nexus is an application written on the .NET framework, that utilizes a client distribution of Reporting Services in order to give us insight into the output generated from SQLDiag. While it is relatively hopping along on 3 legs, we are still very lucky to have it. This video walks you through the initial process of setting up the traces and gives a brief intro in the data you can expect to find.