Data not yet sent to the mirror

This metric tracks the amount of data waiting to be sent from the principal database to the mirror. This is known as the send queue.

Install metric...

Metrics install automatically if you have Redgate Monitor installed.

If you are using Redgate’s SQL Server monitoring tool, Redgate Monitor, you can instantly install and run this metric on your servers.

This metric is described in Grant Fritchey’s Custom Metrics for monitoring mirroring article on Simple Talk.

Use this metric to track the amount of data waiting to be sent from the principal database to the mirror. This is also known as the send queue. For more details, see Database Mirroring Sessions (MSDN article).

Important setup information

Before you can start using this metric, you need to:

  1. Run the following Microsoft procedure on the msdb database you’ll use in the custom metric:
    [sql]USE msdb;
    GO
    EXEC sp_dbmmonitoraddmonitoring;
    GO
    [/sql]This sets up a SQL Agent job that periodically updates information about the mirrored databases on your server. For more information, see http://msdn.microsoft.com/en-us/library/ms403582.aspx.
  2. Make sure the SQL Agent is configured and running on the server. Then you can retrieve information using the sp_dbmmonitorresults procedure.

Metric definition

Name

Data not yet sent to mirror 'InsertDatabaseNameHere'

Description

This metric measures the amount of data (in KBs) waiting to be sent from the principal database to the mirror. This is also known as the send queue.

The T-SQL query that will collect data

Instances to collect from

Select all

Databases to collect from

msdb

Collection frequency

60

Use collected or calculated values

Leave the Use a calculated rate of change between collections check box unchecked

Metric collection

Enabled

Alert definition

If you wanted to add an alert, track the metric values over time to determine sensible high, medium and low thresholds in your mirroring environment.