Database Mirroring State Change Event Class
Applies to: 
SQL Server
Azure SQL Database
The Database Mirroring State Change event class indicates when the state of a mirrored database changes. Include this event class in traces that are monitoring conditions of mirrored databases.
When the Database Mirroring State Change event class is included in a trace the relative overhead is low. The overhead may be greater if the state of the mirrored databases increase.
Data Database Mirroring State Change Event Class Data Columns
| Data Column Name | Data Type | Description | Column ID | Filterable |
|---|---|---|---|---|
| DatabaseID | int | ID of the database specified by the USE database statement or the default database if no USE database statement has been issued for a given instance. SQL Server Profiler displays the name of the database if the ServerName data column is captured in the trace and the server is available. Determine the value for a database by using the DB_ID function. | 3 | Yes |
| DatabaseName | nvarchar | Name of the mirrored database. | 35 | Yes |
| EventClass | int | Type of event = 167. | 27 | No |
| EventSequence | int | Sequence of event class in batch. | 51 | No |
| IntegerData | int | Prior state ID. | 25 | Yes |
| IsSystem | int | Indicates whether the event occurred on a system process or a user process. 1 = system, 0 = user. | 60 | Yes |
| LoginSid | image | Security identification number (SID) of the logged-in user. You can find this information in the sys.server_principals catalog view. Each SID is unique for each login in the server. | 41 | Yes |
| RequestID | int | ID of the request containing the statement. | 49 | Yes |
| ServerName | nvarchar | Name of the instance of Microsoft SQL Server being traced. | 26 | No |
| SessionLoginName | nvarchar | Login name of the user who originated the session. For example, if you connect to SQL Server using Login1 and execute a statement as Login2, SessionLoginName shows Login1 and LoginName shows Login2. This column displays both SQL Server and Windows logins. | 64 | Yes |
| SPID | int | ID of the session on which the event occurred. | 12 | Yes |
| StartTime | datetime | Time at which the event started, if available. | 14 | Yes |
| State | int | New mirroring state ID: 0 = Null Notification 1 = Synchronized Principal with Witness 2 = Synchronized Principal without Witness 3 = Synchronized Mirror with Witness 4 = Synchronized Mirror without Witness 5 = Connection with Principal Lost 6 = Connection with Mirror Lost 7 = Manual Failover 8 = Automatic Failover 9 = Mirroring Suspended 10 = No Quorum 11 = Synchronizing Mirror 12 = Principal Running Exposed |
30 | Yes |
| TextData | ntext | Description of the state change. | 1 | Yes |
| TransactionID | bigint | System-assigned ID of the transaction. | 4 | Yes |