The SQLServer:Database Replica performance object contains performance counters that report information about the secondary databases of an AlwaysOn availability group in SQL Server 2014. This object is valid only on an instance of SQL Server that hosts a secondary replica.
File Bytes Received/sec
Amount of FILESTREAM data received by the secondary replica for the secondary database in the last second.
Log Bytes Received/sec
Amount of log records received by the secondary replica for the database in the last second.
Log remaining for undo
The amount of log in kilobytes remaining to complete the undo phase.
Log Send Queue
Amount of log records in the log files of the primary database, in kilobytes, that has not yet been sent to the secondary replica. This value is sent to the secondary replica from the primary replica. Queue size does not include FILESTREAM files that are sent to a secondary.
Mirrored Write Transaction/sec
Number of transactions that were written to the primary database and then waited to commit until the log was sent to the secondary database, in the last second.
Amount of log records in the log files of the secondary replica that has not yet been redone.
Number of times the redo thread is blocked on locks held by readers of the database.
Redo Bytes Remaining
The amount of log in kilobytes remaining to be redone to finish the reverting phase.
Amount of log records redone on the secondary database in the last second.
Total Log requiring undo
Total kilobytes of log that must be undone.
Delay in waiting for unterminated commit acknowledgement, in milliseconds.