Database Mirroring Connection Event Class
Applies to: 
SQL Server
Azure SQL Database
SQL Server generates a Database Mirroring Connection event to report the status of a transport connection managed by Database Mirroring.
Database Mirroring:Connection Event Class Data Columns
| Data column | Type | Description | Column number | Filterable |
|---|---|---|---|---|
| ApplicationName | nvarchar | The name of the client application that created the connection to an instance of SQL Server. This column is populated with the values passed by the application rather than the displayed name of the program. | 10 | Yes |
| ClientProcessID | int | The ID assigned by the host computer to the process where the client application is running. This data column is populated if the client process ID is provided by the client. | 9 | Yes |
| DatabaseID | int | The ID of the database specified by the USE database statement, or the ID of the default database if no USE databasestatement 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 |
| Error | int | The message ID number in sys.messages for the text in the event. If this event reports an error, this is the SQL Server error number. | 31 | No |
| EventClass | int | The type of event class captured. Always 151 for Database Mirroring Connection. | 27 | No |
| EventSequence | int | Sequence number for this event. | 51 | No |
| EventSubClass | nvarchar | The connection state of this connection. For this event, the subclass is one the following values: Connecting. SQL Server is initiating a transport connection. Connected. SQL Server has established a transport connection. Connect Failed. SQL Server failed to establish a transport connection. Closing. SQL Server is closing the transport connection. Closed. SQL Server has closed the transport connection. Accept. SQL Server has accepted a transport connection from another instance. Send IO Error. SQL Server encountered a transport error while sending a message. Receive IO Error. SQL Server encountered a transport error while receiving a message. |
21 | Yes |
| GUID | uniqueidentifier | The endpoint ID of this connection. | 54 | No |
| HostName | nvarchar | The name of the computer on which the client is running. This data column is populated if the host name is provided by the client. To determine the host name, use the HOST_NAME function. | 8 | Yes |
| IntegerData | int | The number of times this connection has been closed. | 25 | Yes |
| IsSystem | int | Indicates whether the event occurred on a system process or a user process. 0 = user 1 = system |
60 | No |
| LoginSid | image | The security identification number (SID) of the logged-in user. Each SID is unique for each login in the server. | 41 | Yes |
| NTDomainName | nvarchar | The Windows domain to which the user belongs. | 7 | Yes |
| NTUserName | nvarchar | The name of the user that owns the connection that generated this event. | 6 | Yes |
| ObjectName | nvarchar | The conversation handle of the dialog. | 34 | No |
| ServerName | nvarchar | The name of the instance of SQL Server being traced. | 26 | No |
| SPID | int | The server process ID assigned by SQL Server to the process associated with the client. | 12 | Yes |
| StartTime | datetime | The time at which the event started, when available. | 14 | Yes |
| TextData | ntext | The text of the error message related to the event. For events that do not report an error, this field is empty. The error message may either be a SQL Server error message or a Windows error message. | 1 | Yes |
| TransactionID | bigint | The system-assigned ID of the transaction. | 4 | No |