Database Mirroring Monitor (Warnings Page)
New: 14 April 2006
Displays a read-only list of warnings supported on database mirroring events and the specified warning threshold values, if available.
To use SQL Server Management Studio to monitor database mirroring
Columns
Warning
The warnings for which you can define a threshold include:Warning
Threshold at '<server_instance>'
For each of the warnings, displays the current user-specified threshold, if any, for one of the server instances. The full instance name of the server instance is indicated in the corresponding column heading.For more information, see "Remarks," later in this topic.
Set Thresholds
Click this button to set a threshold for one warning on each of the failover partners.For more information, see "Remarks," later in this topic.
Remarks
If information is currently unavailable for a server instance, the cells of the corresponding Threshold at column display a gray background and watermark text. If the monitor is not connected to the server instance, in every cell the grid displays either Not connected to <SYSTEM_NAME> or Not connected to <SYSTEM_NAME>\<instance_name>, depending on whether the instance is the default instance or a named instance. If the monitor is waiting for a query to return, the grid displays Waiting for data… in every cell.
When information is available, the cell for each warning displays either a specified threshold value (and unit of measurement), or Not enabled.
If a threshold is exceeded at the time the status table is refreshed, an event is logged to the Windows event log when the status row is recorded. By default, the status row is recorded once a minute if the monitor is not running. You can configure an alert on each type of logged event by using the SQL Server Agent or another program, such as Microsoft Management Operations Manager (MOM).
On a given partner, the events logged depend on its current role, principal or mirror. However, we recommend that you set a warning threshold for a given event on both partners to ensure that the warning persists if the database fails over. The appropriate threshold for each partner depends on the performance capabilities of that partner's system.
Note
You can also use the sp_dbmmonitorchangealert system stored procedure to configure thresholds for the equivalent events—unsent log, unrecovered log, oldest unsent transaction, and mirror commit overhead. For more information, see sp_dbmmonitorchangealert (Transact-SQL).
The following table shows the event ID associated with each warning.
| Database Mirroring Monitor warning | Event name | Event ID |
|---|---|---|
Warn if the unsent log exceeds the threshold |
Unsent log |
32042 |
Warn if the unrestored log exceeds the threshold |
Unrestored log |
32043 |
Warn if the age of the oldest unsent transaction exceeds the threshold |
Oldest unsent transaction |
32044 |
Warn if the mirror commit overhead exceeds the threshold |
Mirror commit overhead |
32045 |
See Also
Other Resources
How to: Launch Database Mirroring Monitor
Monitoring Database Mirroring
How to: Launch the Configuring Database Mirroring Security Wizard (SQL Server Management Studio)