DB Exclusive locks

Purpose

If too many exclusive locks are held for a long time, performances of the whole system can be impacted. This monitor will help to watch for such situations and generate an alarm if one is detected.

Configuration hints

Create a rule in the table and define the maximum time an exclusive lock must be held before generating an alarm.

You can filter on a database object to apply a different threshold and severity based on the table name.

Aggregate: If active, only one alarm per rule will be generated, reporting the number of exclusive locks ongoing since more than threshold. If inactive, one alarm per lock will be sent, reporting its exact duration.

Surveillance table

Parameter	Description
Active	Use this field to activate or deactivate a line of configuration.
Object Name	The name of the database object to look for. You can use regular expressions, or * to match any object.
Max wait time (sec)	The threshold for the maximum time an exclusive lock can be held, in seconds.
Aggregate	If checked, the alarm will indicate how many matching objects are held by an exclusive lock since too long time. If not checked, the probe will send an alarm per matching object being subject of a too long exclusive lock.
Severity	The level of severity of the alarm generated by this line of surveillance.
Auto clear	If checked, the alarm will be cleared as soon as the alarm condition is not met anymore.
Alarm tag	This field allows to add custom text within the alarm message. %MSG% variable will contain the actual generated message and can be used such as: “my_prefix %MSG% my_suffix”. By default, tag will be used as prefix.
Alarm	If checked, this line of surveillance will be used for alarm generation.
Metric	If checked, this line of surveillance will be used for metric generation.
Report	If checked, this line of surveillance will used for showing threshold and severity in the daily report

Examples

Active	Object Name	Max wait time (sec)	Aggregate	Severity	Auto clear	Alarm tag	Alarm	Metric	Report
true	*	30	false	MAJOR	true	true	false	false

Effect : Sends a MAJOR alarm for each object with an exclusive lock held since 30 seconds or more.

Examples

Active	Object Name	Max wait time (sec)	Aggregate	Severity	Auto clear	Alarm tag	Alarm	Metric	Report
true	LOU.*	30	true	WARNING	true	true	false	false

Effect : Sends an alarm indicating how many objects with name starting by “LOU” are held by an exclusive lock since 30 seconds.

Generated metrics

metricId	metricUnit	metricTarget	metricDescription
LONG_EXCLUSIVE_LOCKS_NUMBER	Seconds	[OBJECT]	Sends the number of exclusive locks matching the filter