14 January 2022

Detecting Connection Timeouts

by Grant Fritchey

3,040 0 Security

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.

Connection timeouts can be difficult to troubleshoot. It’s sometimes not even apparent that a timeout has occurred. However, the connectivity_ring_buffer_recorded Extended Event can show that this has happened. This is a debug event within Extended Events, so some caution is necessary in its use. Microsoft can change the debug events without warning.

You can use SQL Monitor to see that a connection had a timeout. In order to then troubleshoot the issue, you will need to look at the information captured by the Extended Event session defined below.

Metric definition

Name

Detecting Connection Timeouts

Description

You can use SQL Monitor to see that a connection had a timeout. In order to then troubleshoot the issue, you will need to look at the information captured by the Extended Event session defined below.

The T-SQL query that will collect data


		
			
			
Transact-SQL
			
			CREATE EVENT SESSION ConnectionTimeout
ON SERVER
ADD EVENT sqlserver.connectivity_ring_buffer_recorded
(ACTION
(
sqlserver.client_app_name,
sqlserver.client_hostname,
sqlserver.nt_username,
sqlserver.username
)
WHERE (type = 'LoginTimers')
)
ADD TARGET package0.ring_buffer
WITH
(
STARTUP_STATE = ON
);
GO
T-SQL: SELECT Count(*) AS ObjectsAltered
FROM sys.dm_xe_session_targets AS xet
INNER JOIN sys.dm_xe_sessions AS xes
ON xes.address = xet.event_session_address
CROSS APPLY
(SELECT Cast(xet.target_data AS XML)) AS target_data_xml(xml)
CROSS APPLY target_data_xml.xml.nodes('//RingBufferTarget/event') AS xed(event_data)
WHERE xes.name = 'ConnectionTimeout'
AND xet.target_name = 'ring_buffer'
AND DateDiff
(MINUTE,
Convert(DATETIME2,
SwitchOffset(
Convert(DATETIMEOFFSET,xed.event_data.value('(@timestamp)[1]', 'datetime2')),
DateName(TzOffset,SysDateTimeOffset()))
),
GetDate()) < 30; –timeouts recorded in OS ring buffer within the last thirty minutes
			
				
					
				
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						CREATE EVENT SESSION ConnectionTimeout
ON SERVER
ADD EVENT sqlserver.connectivity_ring_buffer_recorded
(ACTION
(
sqlserver.client_app_name,
sqlserver.client_hostname,
sqlserver.nt_username,
sqlserver.username
)
WHERE (type = 'LoginTimers')
)
ADD TARGET package0.ring_buffer
WITH
(
STARTUP_STATE = ON
);
GO
T-SQL: SELECT Count(*) AS ObjectsAltered
FROM sys.dm_xe_session_targets AS xet
INNER JOIN sys.dm_xe_sessions AS xes
ON xes.address = xet.event_session_address
CROSS APPLY
(SELECT Cast(xet.target_data AS XML)) AS target_data_xml(xml)
CROSS APPLY target_data_xml.xml.nodes('//RingBufferTarget/event') AS xed(event_data)
WHERE xes.name = 'ConnectionTimeout'
AND xet.target_name = 'ring_buffer'
AND DateDiff
(MINUTE,
Convert(DATETIME2,
SwitchOffset(
Convert(DATETIMEOFFSET,xed.event_data.value('(@timestamp)[1]', 'datetime2')),
DateName(TzOffset,SysDateTimeOffset()))
),
GetDate()) < 30; –timeouts recorded in OS ring buffer within the last thirty minutes

Instances to collect from

Select All

Databases to collect from

master

Collection frequency

30 Minutes

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

Application Connection Timeout Has Occurred

Description

An application attempting to connect to this server has suffered a timeout

Raise an alert when the metric value goes

above the defined threshholds

Default threshold values

High:
Medium:	1
Low:

Raise an alert when the threshold is passed for

1 time collections

Alert is

DISABLED

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Detecting Connection Timeouts

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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