16 October 2012

Mirroring latency

by Richard Slim

14,405 1 Mirroring

This metric measures the latency of a mirroring stream. This is useful for checking the historical status of mirroring and also alerting when mirroring is delayed.

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This metric measures the latency of a mirroring stream. This is useful for checking the historical status of mirroring and also alerting when mirroring is delayed. Values are displayed in seconds and calculated every minute.

Metric definition

Name

Mirroring latency

Description

The T-SQL query that will collect data


		
			
			
Transact-SQL
			
			DECLARE @MirroredDBToTest sysname
SET @MirroredDBToTest = DB_NAME()
DECLARE @MirroringResults TABLE 
(database_name sysname,
role int,
mirroring_state int,
witness_status int,
log_generation_rate int,
unsent_log int,
send_rate int,
unrestored_log int,
recovery_rate int,
transaction_delay int,
transactions_per_sec int,
average_delay int,
time_recorded datetime,
time_behind datetime,
local_time datetime)

INSERT INTO @MirroringResults
EXEC msdb..sp_dbmmonitorresults @database_name = @MirroredDBToTest

SELECT DATEDIFF(S,time_behind, time_recorded) AS Latency FROM @MirroringResults
			
				
					
				
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						DECLARE @MirroredDBToTest sysname
SET @MirroredDBToTest = DB_NAME()
DECLARE @MirroringResults TABLE 
(database_name sysname,
role int,
mirroring_state int,
witness_status int,
log_generation_rate int,
unsent_log int,
send_rate int,
unrestored_log int,
recovery_rate int,
transaction_delay int,
transactions_per_sec int,
average_delay int,
time_recorded datetime,
time_behind datetime,
local_time datetime)
 
INSERT INTO @MirroringResults
EXEC msdb..sp_dbmmonitorresults @database_name = @MirroredDBToTest
 
SELECT DATEDIFF(S,time_behind, time_recorded) AS Latency FROM @MirroringResults

Instances to collect from

Select the instance containing mirrored databases

Databases to collect from

the names of databases that use mirroring

Collection frequency

Use collected or calculated values

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

Metric collection

Enabled

Alert definition

Alert name

Mirroring latency increased

Description

This alert is raised when the latency of a mirrored database (in seconds) is greater than the threshold specified. You may consider checking the state of the mirrored database.

Raise an alert when the metric value goes

Above the defined threshholds

Default threshold values

High:	259
Medium:
Low:

Raise an alert when the threshold is passed for

1 collection

Alert is

Enabled

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Mirroring latency

Metric definition

Name

Description

The T-SQL query that will collect data

Instances to collect from

Databases to collect from

Collection frequency

Use collected or calculated values

Metric collection

Alert definition

Alert name

Description

Raise an alert when the metric value goes

Default threshold values

Raise an alert when the threshold is passed for

Alert is

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