Database Mirror Witness Status Summary

RABurri.SQLServer.2008.Mirroring.MirrorDependsOnDBWitnessState (DependencyMonitor)

Checks if a database mirror witness is connected.

Knowledge Base article:

Summary

This monitor checks if the witness of a SQL Server DB mirror is connected.

Causes

Warning state when the witness is disconnected.

Resolutions

Connect to the DB Engines and correct issues that caused the mirror witness to fail.

Use ‘SQL Server Management Studio’ to access the mirroring page in a DB’s properties. Or use the ‘Database Mirroring Monitor’.

Additional

Monitor is implemented as a summary roll up monitor to assure raising only a single alert.

Element properties:

Target

RABurri.SQLServer.2008.Mirroring.ComponentGroup

Parent Monitor

System.Health.AvailabilityState

Algorithm

WorstOf

Source Monitor

RABurri.SQLServer.2008.MirroredDatabase.WitnessState.Monitor

Relationship

RABurri.SQLServer.2008.Mirror.ComponentGroupContainsDB

Category

AvailabilityHealth

Enabled

True

Alert Generate

True

Alert Severity

MatchMonitorHealth

Alert Priority

Normal

Alert Auto Resolve

True

Remotable

True

Accessibility

Public

Alert Message

Database Mirror Witness not Connected

Database mirror {0} has lost connection to its witness.

Source Code:

<DependencyMonitor ID="RABurri.SQLServer.2008.Mirroring.MirrorDependsOnDBWitnessState" Accessibility="Public" Enabled="true" Target="RABurri.SQLServer.2008.Mirroring.ComponentGroup" ParentMonitorID="Health!System.Health.AvailabilityState" Remotable="true" Priority="Normal" RelationshipType="RABurri.SQLServer.2008.Mirror.ComponentGroupContainsDB" MemberMonitor="RABurri.SQLServer.2008.MirroredDatabase.WitnessState.Monitor">

  <Category>AvailabilityHealth</Category>

  <AlertSettings AlertMessage="RABurri.SQLServer.2008.Mirroring.MirrorDependsOnDBWitnessState_AlertMessageResourceID">

    <AlertOnState>Warning</AlertOnState>

    <AutoResolve>true</AutoResolve>

    <AlertPriority>Normal</AlertPriority>

    <AlertSeverity>MatchMonitorHealth</AlertSeverity>

    <AlertParameters>

      <AlertParameter1>$Target/Property[Type="MirroringLibrary!RABurri.SQLServer.Mirroring.ComponentGroup"]/DatabaseName$</AlertParameter1>

    </AlertParameters>

  </AlertSettings>

  <Algorithm>WorstOf</Algorithm>

</DependencyMonitor>