Windows Management Instrumentation

Windows Management Instrumentation (WMI) is a Microsoft implementation of Web-Based Enterprise Management (WBEM), an industry initiative that establishes management infrastructure standards. WMI supplies administrators with the tools to explore, understand, and use various system devices, resources, and applications of Microsoft operating systems and servers. WMI includes a rich infrastructure that enables efficient and scalable monitoring, data collection, and problem recognition. Think of WMI as a set of functionalities embedded into Microsoft operating systems and servers—including SQL Server—that allows for local and remote monitoring and management.

WMI is a huge initiative and certainly deserves an entire book of its own. However, what administrators need to know is that the architecture of WMI enables extensibility through the use of providers, which are Dynamic Link Library files that interface between WMI and software or hardware components.

Each provider contains a set of WMI classes. Each WMI class represents a manageable entity, exposes information through properties, and enables the execution of some actions through methods. Because a provider is designed to access some specific management information, the WMI repository is logically divided into several areas called namespaces. Each namespace contains a set of providers with their related classes specific to a management area.

Administrators should also know that SQL Server, as part of its installation process, adds two providers to the WMI repository (WMI Provider for Configuration Management and WMI Provider for Server Events):

• The WMI Provider for Configuration Management enables administrators to use WMI to manage SQL Server services, SQL Server client and server network settings, and server aliases. For example, after a connection is established with the WMI provider on a remote computer, not only is it possible to retrieve information about SQL Server instances, but it’s also possible to perform actions on them such as starting and stopping the instances.

• The WMI Provider for Server Events enables administrators to use WMI to monitor events in SQL Server. Included are Data Definition Language (DDL) events that occur when databases are created, altered, or dropped and when tables are created, altered, or dropped, for example. Additionally, software developers can write code that responds to these events, and they can even author their own set of monitoring tools. Administrators can also create a SQL Server Agent alert that is raised when a specific SQL Server event occurs that is monitored by the WMI Provider for Server Events.