0000 Troubleshooting Workflows
This section of the Wiki contains troubleshooting techniques for a variety of Microsoft SQL Server client-server connectivity issues. While there are many Knowledge Base articles and forums on the Internet that deal with specific issues, the workflows presented here are more generalized and help you work through unfamiliar issues in a structured manner.
When troubleshooting SQL connectivity issues, the thing most often being debugged is your data center. It is very rare that the driver has a connectivity bug and the issue is usually related to an ancillary technology that is used by the driver, such as:
- The DNS service
- The Windows security subsystem (LSSAS) and domain controller
- The file system and registry
- Firewalls, routers, and switches
- Network drivers
- Antivirus and other filter drivers
- Communication bottlenecks between a VM and the host server
Before you start a troubleshooting workflow, understand what your error message means and what to do about it. You can also check out public articles and troubleshooters that have already been published.
This section contains data about the client machine, server machine, and user to gather and have on-hand that will help kick-start any troubleshooting. It also goes over some important questions to narrow the scope of the issue, such as whether it only affects a single machine to being a data-center-wide issue, and some features about your data center, such as whether the issue is local to a single domain or only occurs cross-domain, etc. Knowing these things can rapidly rule out a number of scenarios and narrow the focus of troubleshooting.
Most issues fall into one of a few types. It is important to determine which category of issue you are experiencing as the workflows can be quite different, for example, a consistent issue vs. an intermittent issue.
The workflow may not help you resolve your issue completely but should serve to narrow the issue as much as possible and, should you need to contact Microsoft Support, serve to make your support experience more focused and efficient.
A workflow may ask you to use some existing tools on your machine, to download some tools from the Microsoft download site or some other sites, such as those from SysInternals, or to use some scripts or tools from this GitHub site. It may also leverage some Knowledge Base articles that are relevant to your issue.
The workflows are for client-server connection issues using SQL Server drivers and providers to connect to SQL Server. Networking issues related to log shipping, Service Broker, and Always On replication are not covered as they do not use these drivers.
The workflows do not deal with API programming but with driver and infrastructure issues that may cause connectivity issues between your application and Microsoft SQL Server.
Your network may or may not have advanced monitoring systems. These workflows assume that you do not.