SQL 2008 Mirrored DB Witness Discovery Provider

Microsoft.SQLServer.2008.Mirroring.WitnessDiscoveryProvider (DataSourceModuleType)

This module type is used to discover instances of Microsoft SQL Server 2008 Mirrored Databases Witnesses. The module connects to SQL Server and discovers all mirrored databases witnesses together with properties.

Element properties:

TypeDataSourceModuleType
IsolationAny
AccessibilityInternal
RunAsMicrosoft.SQLServer.SQLDiscoveryAccount
OutputTypeSystem.Discovery.Data

Member Modules:

ID Module Type TypeId RunAs 
DS DataSource Microsoft.Windows.TimedScript.DiscoveryProvider Default

Overrideable Parameters:

IDParameterTypeSelectorDisplay NameDescription
IntervalSecondsint$Config/IntervalSeconds$Interval (sec)
SyncTimestring$Config/SyncTime$Synchronization Time
ExcludeListstring$Config/ExcludeList$Exclude ListA comma-separated list of database instances that should be excluded from discovery. You can use the wildcard * to exclude all instances.
TimeoutSecondsint$Config/TimeoutSeconds$Timeout (sec)

Source Code:

<DataSourceModuleType ID="Microsoft.SQLServer.2008.Mirroring.WitnessDiscoveryProvider" Accessibility="Internal" RunAs="SQL!Microsoft.SQLServer.SQLDiscoveryAccount">
<Configuration>
<xsd:element xmlns:xsd="http://www.w3.org/2001/XMLSchema" name="IntervalSeconds" type="xsd:integer"/>
<xsd:element xmlns:xsd="http://www.w3.org/2001/XMLSchema" name="SyncTime" type="xsd:string"/>
<xsd:element xmlns:xsd="http://www.w3.org/2001/XMLSchema" name="ComputerName" type="xsd:string"/>
<xsd:element xmlns:xsd="http://www.w3.org/2001/XMLSchema" name="SQLConnectionString" type="xsd:string"/>
<xsd:element xmlns:xsd="http://www.w3.org/2001/XMLSchema" name="SQLInstanceName" type="xsd:string"/>
<xsd:element xmlns:xsd="http://www.w3.org/2001/XMLSchema" name="ExcludeList" type="xsd:string"/>
<xsd:element xmlns:xsd="http://www.w3.org/2001/XMLSchema" name="TimeoutSeconds" type="xsd:int"/>
</Configuration>
<OverrideableParameters>
<OverrideableParameter ID="IntervalSeconds" ParameterType="int" Selector="$Config/IntervalSeconds$"/>
<OverrideableParameter ID="SyncTime" ParameterType="string" Selector="$Config/SyncTime$"/>
<OverrideableParameter ID="ExcludeList" ParameterType="string" Selector="$Config/ExcludeList$"/>
<OverrideableParameter ID="TimeoutSeconds" ParameterType="int" Selector="$Config/TimeoutSeconds$"/>
</OverrideableParameters>
<ModuleImplementation>
<Composite>
<MemberModules>
<DataSource ID="DS" TypeID="Windows!Microsoft.Windows.TimedScript.DiscoveryProvider">
<IntervalSeconds>$Config/IntervalSeconds$</IntervalSeconds>
<SyncTime>$Config/SyncTime$</SyncTime>
<ScriptName>DiscoverSQL2008MirroringWitness.vbs</ScriptName>
<Arguments>$MPElement$ $Target/Id$ $Config/ComputerName$ $Config/SQLConnectionString$ $Config/SQLInstanceName$ "Exclude:$Config/ExcludeList$" $Target/Property[Type="SQL!Microsoft.SQLServer.DBEngine"]/TcpPort$</Arguments>
<ScriptBody><Script>'#Include File:Common.vbs

Option Explicit
SetLocale("en-us")

Dim oAPI
Set oAPI = MOMCreateObject("MOM.ScriptAPI")

Function MomCreateObject(ByVal sProgramId)
Dim oError
Set oError = New Error

On Error Resume Next
Set MomCreateObject = CreateObject(sProgramId)
oError.Save
On Error Goto 0

If oError.Number &lt;&gt; 0 Then ThrowScriptError "Unable to create automation object '" &amp; sProgramId &amp; "'", oError
End Function

'#Include File:ErrorHandling.vbs

Const EVENT_TYPE_ERROR = 1

Class Error
Private m_lNumber
Private m_sSource
Private m_sDescription
Private m_sHelpContext
Private m_sHelpFile
Public Sub Save()
m_lNumber = Err.number
m_sSource = Err.Source
m_sDescription = Err.Description
m_sHelpContext = Err.HelpContext
m_sHelpFile = Err.helpfile
End Sub
Public Sub Raise()
Err.Raise m_lNumber, m_sSource, m_sDescription, m_sHelpFile, m_sHelpContext
End Sub
Public Sub Clear()
m_lNumber = 0
m_sSource = ""
m_sDescription = ""
m_sHelpContext = ""
m_sHelpFile = ""
End Sub
Public Default Property Get Number()
Number = m_lNumber
End Property
Public Property Get Source()
Source = m_sSource
End Property
Public Property Get Description()
Description = m_sDescription
End Property
Public Property Get HelpContext()
HelpContext = m_sHelpContext
End Property
Public Property Get HelpFile()
HelpFile = m_sHelpFile
End Property
End Class

Function ThrowScriptErrorNoAbort(ByVal sMessage, ByVal oErr)
On Error Resume Next
oAPI.LogScriptEvent WScript.ScriptName, 4001, EVENT_TYPE_ERROR, sMessage &amp; ". " &amp; oErr.Description
End Function

Function ThrowScriptError(ByVal sMessage, ByVal oErr)
On Error Resume Next
ThrowScriptErrorNoAbort sMessage, oErr
Quit()
End Function

Sub WriteToEventLogAndExit(ByVal message)
oAPI.LogScriptEvent WScript.ScriptName, 4002, EVENT_TYPE_ERROR, message
WScript.Quit()
End Sub
'#Include File:WMI.vbs

Function EscapeWQLString (ByVal strValue)
On Error Resume Next
Err.Clear
EscapeWQLString = Replace(strValue, "'", "\'")
End Function

Function WMIGetProperty(oWmi, sPropName, nCIMType, ErrAction)
Dim sValue, oWmiProp

If Not IsValidObject(oWmi) Then
If (ErrAction And ErrAction_ThrowError) = ErrAction_ThrowError Then _
ThrowScriptErrorNoAbort "Accessing property on invalid WMI object.", Err

If (ErrAction And ErrAction_Abort) = ErrAction_Abort Then _
Quit()

WMIGetProperty = ""
Exit Function
End If

On Error Resume Next
Set oWmiProp = oWmi.Properties_.Item(sPropName)
If Err.Number &lt;&gt; 0 Then
If (ErrAction And ErrAction_ThrowError) = ErrAction_ThrowError Then _
ThrowScriptErrorNoAbort "An error occurred while accessing WMI property: '" &amp; sPropName &amp; "'.", Err

If (ErrAction And ErrAction_Abort) = ErrAction_Abort Then _
Quit()
End If
On Error GoTo 0

If IsValidObject(oWmiProp) Then
sValue = oWmiProp.Value

If IsNull(sValue) Then
'
' If value is null, return blank to avoid any issues
'
WMIGetProperty = ""

Else

Select Case (oWmiProp.CIMType)
Case wbemCimtypeString, wbemCimtypeSint16, wbemCimtypeSint32, wbemCimtypeReal32, wbemCimtypeReal64, wbemCimtypeSint8, wbemCimtypeUint8, wbemCimtypeUint16, wbemCimtypeUint32, wbemCimtypeSint64, wbemCimtypeUint64:
If Not oWmiProp.IsArray Then
WMIGetProperty = Trim(CStr(sValue))
Else
WMIGetProperty = Join(sValue, ", ")
End If

Case wbemCimtypeBoolean:
If sValue = 1 Or UCase(sValue) = "TRUE" Then
WMIGetProperty = "True"
Else
WMIGetProperty = "False"
End If

Case wbemCimtypeDatetime:
Dim sTmpStrDate

'
' First attempt to convert the whole wmi date string
'
sTmpStrDate = Mid(sValue, 5, 2) &amp; "/" &amp; _
Mid(sValue, 7, 2) &amp; "/" &amp; _
Left(sValue, 4) &amp; " " &amp; _
Mid (sValue, 9, 2) &amp; ":" &amp; _
Mid(sValue, 11, 2) &amp; ":" &amp; _
Mid(sValue, 13, 2)
If IsDate(sTmpStrDate) Then
WMIGetProperty = CDate(sTmpStrDate)
Else

'
' Second, attempt just to convert the YYYYMMDD
'
sTmpStrDate = Mid(sValue, 5, 2) &amp; "/" &amp; _
Mid(sValue, 7, 2) &amp; "/" &amp; _
Left(sValue, 4)
If IsDate(sTmpStrDate) Then
WMIGetProperty = CDate(sTmpStrDate)
Else
'
' Nothing works - return passed in string
'
WMIGetProperty = sValue
End If

End If

Case Else:
WMIGetProperty = ""
End Select
End If
Else

If (ErrAction And ErrAction_ThrowError) = ErrAction_ThrowError Then _
ThrowScriptErrorNoAbort "An error occurred while accessing WMI property: '" &amp; sPropName &amp; "'.", Err

If (ErrAction And ErrAction_Abort) = ErrAction_Abort Then _
Quit()

WMIGetProperty = ""

End If


If (ErrAction And ErrAction_Trace) = ErrAction_Trace Then _
WScript.Echo " + " &amp; sPropName &amp; " :: '" &amp; WMIGetProperty &amp; "'"

End Function

Function WMIExecQuery(ByVal sNamespace, ByVal sQuery)
'
' WMIExecQuery :: Executes the WMI query and returns the result set.
'
'
Dim oWMI, oQuery, nInstanceCount
Dim e
Set e = New Error
On Error Resume Next
Set oWMI = GetObject(sNamespace)
e.Save
On Error GoTo 0
If IsEmpty(oWMI) Then
ThrowScriptErrorNoAbort "Unable to open WMI Namespace '" &amp; sNamespace &amp; "'. Check to see if the WMI service is enabled and running, and ensure this WMI namespace exists.", e
ThrowEmptyDiscoveryData
End If

On Error Resume Next
Set oQuery = oWMI.ExecQuery(sQuery)
e.Save
On Error GoTo 0
If IsEmpty(oQuery) Or e.Number &lt;&gt; 0 Then
ThrowScriptError "The Query '" &amp; sQuery &amp; "' returned an invalid result set. Please check to see if this is a valid WMI Query.", e
End If

'Determine if we queried a valid WMI class - Count will return 0 or empty
On Error Resume Next
nInstanceCount = oQuery.Count
e.Save
On Error GoTo 0
If e.Number &lt;&gt; 0 Then
ThrowScriptError "The Query '" &amp; sQuery &amp; "' did not return any valid instances. Please check to see if this is a valid WMI Query.", e
End If

Set WMIExecQuery = oQuery

End Function

Function GetFirstItemFromWMIQuery(ByRef oQuery)
ON ERROR RESUME NEXT
Err.Clear
Dim oResult
Set oResult = oQuery.ItemIndex(0)
if Err.number &lt;&gt; 0 then
Err.Clear
Dim oObject
For Each oObject in oQuery
Set oResult = oObject
Exit For
Next
end if
Set GetFirstItemFromWMIQuery = oResult
End Function
'#Include File:ConnectionString.vbs

Function BuildConnectionString(strServer, strDatabase)
ON ERROR RESUME NEXT
Err.Clear

Dim dataSource
dataSource = BuildServerName(strServer, "")
BuildConnectionString = "Data Source=" &amp; EscapeConnStringValue(dataSource) &amp; ";Initial Catalog=" &amp; EscapeConnStringValue(strDatabase) &amp; ";Integrated Security=SSPI"
End Function

Function BuildConnectionStringWithPort(ByVal strServer, ByVal strDatabase, ByVal tcpPort)
ON ERROR RESUME NEXT
Err.Clear

Dim dataSource
dataSource = strServer
If ((tcpPort &lt;&gt; "0") And (tcpPort &lt;&gt; "")) Then
dataSource = dataSource &amp; "," &amp; tcpPort
End If
BuildConnectionStringWithPort = "Data Source=" &amp; EscapeConnStringValue(dataSource) &amp; ";Initial Catalog=" &amp; EscapeConnStringValue(strDatabase) &amp; ";Integrated Security=SSPI"
End Function

' This function should be used to escape Connection String keywords.
Function EscapeConnStringValue (ByVal strValue)
ON ERROR RESUME NEXT
Err.Clear

EscapeConnStringValue = """" + Replace(strValue, """", """""") + """"
End Function

Function EscapeWQLString (ByVal strValue)
ON ERROR RESUME NEXT
Err.Clear

EscapeWQLString = Replace(strValue, "'", "\'")
End Function

Function GetTcpPort (ByVal strServer)
ON ERROR RESUME NEXT
Err.Clear

Dim tcpPort
tcpPort = ""

Call BuildServerName(strServer, tcpPort)

GetTcpPort = tcpPort

End Function

Function BuildServerName(ByVal strServer, ByRef tcp)
ON ERROR RESUME NEXT
Err.Clear

Dim pathArray, instanceName, computerName, ip, serverName
Dim oWMI, oQuery

ip= ""

pathArray = Split(strServer, "\")
computerName = pathArray(0)
instanceName = "MSSQLSERVER"
if (pathArray.Count &gt; 1) Then
instanceName = pathArray(1)
End If

serverName = strServer

Set oWMI = GetObject("winmgmts:\\" &amp; computerName &amp; "\root\Microsoft\SqlServer\" &amp; SQL_WMI_NAMESPACE)
Set oQuery = oWMI.ExecQuery("SELECT * FROM ServerNetworkProtocolProperty WHERE ProtocolName = 'Tcp' AND InstanceName = '"&amp; EscapeWQLString(instanceName) &amp;"' AND PropertyName = 'ListenOnAllIPs'")

If oQuery.Count &gt;0 Then
Dim isListenAll
Set isListenAll = GetFirstItemFromWMIQuery(oQuery)
If(isListenAll.PropertyNumVal = 1) Then
Set oQuery = oWMI.ExecQuery("SELECT * FROM ServerNetworkProtocolProperty WHERE ProtocolName = 'Tcp' AND InstanceName = '"&amp; EscapeWQLString(instanceName) &amp;"' AND IPAddressName = 'IPAll' AND (PropertyName = 'TcpPort' OR PropertyName = 'TcpDynamicPorts') AND PropertyStrVal &lt;&gt; ''")

If (oQuery.Count &gt; 0) Then
tcp = GetFirstItemFromWMIQuery(oQuery).PropertyStrVal

If ((tcp &lt;&gt; "0") And (tcp &lt;&gt; "")) Then
serverName = serverName &amp; "," &amp; tcp
Else tcp = ""
End If
End If
Else
Set oQuery = oWMI.ExecQuery("SELECT * FROM ServerNetworkProtocolProperty WHERE ProtocolName = 'Tcp' AND InstanceName = '"&amp; EscapeWQLString(instanceName) &amp;"' AND IPAddressName &lt;&gt; '' AND PropertyName = 'Enabled' AND PropertyNumVal = 1")
If (oQuery.Count &gt; 0) Then
Dim ipAddressName
ipAddressName = GetFirstItemFromWMIQuery(oQuery).IPAddressName
Set oQuery = oWMI.ExecQuery("SELECT * FROM ServerNetworkProtocolProperty WHERE ProtocolName = 'Tcp' AND InstanceName = '"&amp; EscapeWQLString(instanceName) &amp;"' AND IPAddressName = '"&amp; EscapeWQLString(ipAddressName) &amp;"' AND (PropertyName = 'TcpPort' OR PropertyName = 'TcpDynamicPorts') AND PropertyStrVal &lt;&gt; ''")
If (oQuery.Count &gt; 0) Then
tcp = GetFirstItemFromWMIQuery(oQuery).PropertyStrVal
End If
Set oQuery = oWMI.ExecQuery("SELECT * FROM ServerNetworkProtocolProperty WHERE ProtocolName = 'Tcp' AND InstanceName = '"&amp; EscapeWQLString(instanceName) &amp;"' AND IPAddressName = '"&amp; EscapeWQLString(ipAddressName) &amp;"' AND PropertyName = 'IpAddress' AND PropertyStrVal &lt;&gt; ''")
If (oQuery.Count &gt; 0) Then
ip = GetFirstItemFromWMIQuery(oQuery).PropertyStrVal
End If
If ip &lt;&gt; "" Then
serverName = ip
End If
If ((tcp &lt;&gt; "0") And (tcp &lt;&gt; "")) Then
serverName = servername &amp; "," &amp; tcp
Else tcp = ""
End If
End If
End If
End If
On Error Goto 0
BuildServerName = serverName
End Function

Public Function IsValidDestination(dbConnection, serverName, instanceName, isADODB)
Dim destinationTestQuery
destinationTestQuery = "select SERVERPROPERTY('MachineName') as ServerName, @@servicename as InstanceName"
if 0 = Err.number then
Dim queryResult
if isADODB then
Set queryResult = dbConnection.ExecuteQuery(destinationTestQuery)
else
Set queryResult = dbConnection.Execute(destinationTestQuery)
end if
if Not queryResult.EOF then
Dim queryServerName : queryServerName = UCase(queryResult("ServerName").Value)
Dim queryInstanceName : queryInstanceName = UCase(queryResult("InstanceName").Value)
Dim serverNameWithoutDomain : serverNameWithoutDomain = serverName
Dim dotPosition : dotPosition = InStr(1, serverName, ".")
if Not IsNull(dotPosition) And (dotPosition &gt; 0) then
serverNameWithoutDomain = Left(serverName, dotPosition - 1)
end if
if (UCase(serverNameWithoutDomain) = queryServerName) And (UCase(instanceName) = queryInstanceName) then
IsValidDestination = true
Exit Function
end if
end if
end if
IsValidDestination = false
End Function

'NOTE: This will NOT work without SQLADODB.vbs /DKalinin/
'RETURNS:
Public Function SmartConnect(cnADOConnection, connectionStr, tcp, serverName, instanceName, databaseName)
ON ERROR RESUME NEXT
'try to use SQL server browser
Dim strProv : strProv = BuildConnectionStringWithPort(connectionStr, databaseName, "")
Err.Clear
Dim res : res = cnADOConnection.Open(strProv, "sqloledb", 10)
'use original tcp port and try to connect again
if (0 &lt;&gt; Err.number) Or (Not IsValidDestination(cnADOConnection, serverName, instanceName, true)) then
strProv = BuildConnectionStringWithPort(connectionStr, databaseName, tcp)
Err.Clear
res = cnADOConnection.Open(strProv, "sqloledb", 10)
'get fresh tcp port and try to connect again
if (0 &lt;&gt; Err.number) Or (Not IsValidDestination(cnADOConnection, serverName, instanceName, true)) then
Err.Clear
strProv = BuildConnectionString(connectionStr, databaseName)
res = cnADOConnection.Open(strProv, "sqloledb", 30)

if (0 &lt;&gt; Err.number) Or (Not IsValidDestination(cnADOConnection, serverName, instanceName, true)) then
cnADOConnection.HandleOpenConnectionErrorContinue databaseName, serverName, instanceName
SmartConnect = False
Exit Function
end if
end if
end if
SmartConnect = res
End Function


'NOTE: This WILL work without SQLADODB.vbs /DKalinin/
Public Function SmartConnectWithoutSQLADODB(connectionStr, tcp, serverName, instanceName, databaseName)
ON ERROR RESUME NEXT
Dim cnADOConnection
Set cnADOConnection = MomCreateObject("ADODB.Connection")
cnADOConnection.Provider = "sqloledb"
cnADOConnection.ConnectionTimeout = 30
'try to use SQL server browser
Dim strProv : strProv = BuildConnectionString(connectionStr, databaseName)
Err.Clear
cnADOConnection.Open strProv
'use original tcp port and try to connect again
if (0 &lt;&gt; Err.number) Or (Not IsValidDestination(cnADOConnection, serverName, instanceName, false)) then
Err.Clear
strProv = BuildConnectionStringWithPort(connectionStr, databaseName, tcp)
cnADOConnection.Open strProv
'get fresh tcp port and try to connect again
if (0 &lt;&gt; Err.number) Or (Not IsValidDestination(cnADOConnection, serverName, instanceName, false)) then
Err.Clear
strProv = BuildConnectionString(connectionStr, databaseName)
cnADOConnection.Open strProv

if (0 &lt;&gt; Err.number) Or (Not IsValidDestination(cnADOConnection, serverName, instanceName, false)) then
cnADOConnection.HandleOpenConnectionErrorContinue databaseName, serverName, instanceName
Set SmartConnectWithoutSQLADODB = Nothing
Exit Function
end if
end if
end if
Set SmartConnectWithoutSQLADODB = cnADOConnection
End Function

'#Include File:DatabaseHelpers.vbs

Function ExtractHostNameFromEndpoint(ByVal sEndpoint)
If sEndpoint = "" Then
ExtractHostNameFromEndpoint = ""
Exit Function
End If
Dim oRegEx, oMatches
Set oRegEx = MomCreateObject("VBScript.RegExp")
oRegEx.Pattern = "://(.+):"
Set oMatches = oRegEx.Execute(sEndpoint)
If oMatches.Count &gt; 0 Then
If oMatches(0).SubMatches.Count &gt; 0 Then
ExtractHostNameFromEndpoint = oMatches(0).SubMatches(0)
Else
ExtractHostNameFromEndpoint = sEndpoint
End If
Else
ExtractHostNameFromEndpoint = sEndpoint
End If
End Function

Function GetMirroringLevelName(ByVal nSafetyLevel, ByVal sWitnessName)
GetMirroringLevelName = "Unknown state"
If nSafetyLevel = 1 Then
GetMirroringLevelName = "High-performance mode"
Else
If sWitnessName = "" Then
GetMirroringLevelName = "High-safety mode without automatic failover"
Else
GetMirroringLevelName = "High-safety mode with automatic failover"
End If
End If
End Function

Function IsExcluded(ByVal sDatabase, ByVal sExcludeList)
Dim aExcludes, bMatch, nIndex

bMatch = False
If Trim(sExcludeList) = "*" Then
bMatch = True
Else
aExcludes = Split(sExcludeList, ",")
For nIndex = 0 To UBound(aExcludes)
If LCase(sDatabase) = LCase(Trim(aExcludes(nIndex))) Then
bMatch = True
End If
Next
End If
IsExcluded = bMatch
End Function
'#Include File:DiscoverSQL2008MirroringWitness.vbs
'Copyright (c) Microsoft Corporation. All rights reserved.
' Parameters that should be passed to this script
' 0 MPElement ID ($MPElement$)
' 1 Target Id for ME this rule is running against ($Target/Id$)
' 2 Computer Name
' 3 SQL Connection String for the instance that the DBs are being discovered on
' 4 SQL Instance that this rule is being run for
' 5 Exlcuded database list (prefixed with Exclude:)

Const SQL_DISCOVERY_CONNECT_FAILURE = -1
Const SQL_DISCOVERY_QUERY_FAILURE = -2
Const SQL_DISCOVERY_SUCCESS = 0

Dim GetMirroredDatabasesQuery
GetMirroredDatabasesQuery = "SELECT " &amp;_
" database_name, " &amp;_
" mirroring_guid, " &amp;_
" principal_server_name, " &amp;_
" mirror_server_name, " &amp;_
" partner_sync_state, " &amp;_
" safety_level " &amp;_
" FROM sys.database_mirroring_witnesses"

Dim oArgs
Set oArgs = WScript.Arguments
If oArgs.Count &lt;&gt; 7 Then
Wscript.Quit -1
End If

Dim SourceID, ManagedEntityId, InstanceName, ConnectionString, TargetComputer, ExcludeList, sTcpPort

SourceId = oArgs(0)
ManagedEntityId = oArgs(1)
TargetComputer = oArgs(2)
ConnectionString = oArgs(3)
InstanceName = oArgs(4)
ExcludeList = Mid(oArgs(5), 9)
sTcpPort = oArgs(6)

Dim oDiscoveryData
Set oDiscoveryData = oAPI.CreateDiscoveryData(0, SourceId, ManagedEntityId)

If DoWitnessDiscovery() &lt; 0 Then
oDiscoveryData.IsSnapshot = False
End If
Call oAPI.Return(oDiscoveryData)
WScript.Quit()

Function DoWitnessDiscovery()
If Len(ExcludeList) &lt; 0 Then
WriteToEventLogAndExit("Database exclusion list invalid in Mirroring Witness Discovery. Aborting discovery.")
End If

Dim e
Set e = New Error

Dim cnADOConnection
Set cnADOConnection = SmartConnectWithoutSQLADODB(ConnectionString, sTcpPort, TargetComputer, InstanceName, "master")
if cnADOConnection Is Nothing Then
DoWitnessDiscovery = SQL_DISCOVERY_CONNECT_FAILURE
ThrowScriptErrorNoAbort "Cannot connect to SQL instance '" &amp; InstanceName &amp; "'", e
Exit Function
End If

' Query for the list of mirrored databases
Dim oResults
e.Clear
On Error Resume Next
Set oResults = cnADOConnection.Execute(GetMirroredDatabasesQuery)
e.Save
On Error Goto 0
If e.Number &lt;&gt; 0 Then
DoWitnessDiscovery = SQL_DISCOVERY_QUERY_FAILURE
ThrowScriptErrorNoAbort "Query execution failed for SQL instance '" &amp; InstanceName &amp; "'", e
Exit Function
End If

Dim bWitnessRoleCreated, oWitnessRole
bWitnessRoleCreated = False
Dim oWitnessInstance, oMirroringGroup, oRelationship
Dim sDBName, sMirroringGUID, sPrincipalInstance, sMirrorInstance, nState, nSafetyLevel
Do While Not oResults.EOF
sDBName = oResults(0)

If Not(IsExcluded(sDBName, ExcludeList)) Then
sMirroringGUID = oResults(1)
sPrincipalInstance = oResults(2)
sMirrorInstance = oResults(3)
nState = oResults(4)
nSafetyLevel = oResults(5)

If Not bWitnessRoleCreated Then
Set oWitnessRole = oDiscoveryData.CreateClassInstance("$MPElement[Name='Microsoft.SQLServer.2008.Mirroring.WitnessRole']$")
With oWitnessRole
.AddProperty "$MPElement[Name='System!System.Entity']/DisplayName$", "Witness Role"

.AddProperty "$MPElement[Name='Windows!Microsoft.Windows.Computer']/PrincipalName$", TargetComputer
.AddProperty "$MPElement[Name='SQL!Microsoft.SQLServer.ServerRole']/InstanceName$", InstanceName
End With
Call oDiscoveryData.AddInstance(oWitnessRole)
bWitnessRoleCreated = True
End If

Set oWitnessInstance = oDiscoveryData.CreateClassInstance("$MPElement[Name='Microsoft.SQLServer.2008.Mirroring.Witness']$")
With oWitnessInstance
.AddProperty "$MPElement[Name='System!System.Entity']/DisplayName$", "Witness for '" &amp; sDBName &amp; "' database"

.AddProperty "$MPElement[Name='Windows!Microsoft.Windows.Computer']/PrincipalName$", TargetComputer
.AddProperty "$MPElement[Name='SQL!Microsoft.SQLServer.ServerRole']/InstanceName$", InstanceName
.AddProperty "$MPElement[Name='Microsoft.SQLServer.2008.Mirroring.Witness']/MirroringGUID$", sMirroringGUID

.AddProperty "$MPElement[Name='Microsoft.SQLServer.2008.Mirroring.Witness']/DatabaseName$", sDBName
.AddProperty "$MPElement[Name='Microsoft.SQLServer.2008.Mirroring.Witness']/Principal$", ExtractHostNameFromEndpoint(sPrincipalInstance)
.AddProperty "$MPElement[Name='Microsoft.SQLServer.2008.Mirroring.Witness']/Mirror$", ExtractHostNameFromEndpoint(sMirrorInstance)
.AddProperty "$MPElement[Name='Microsoft.SQLServer.2008.Mirroring.Witness']/Level$", GetMirroringLevelName(nSafetyLevel, ConnectionString)
End With
Call oDiscoveryData.AddInstance(oWitnessInstance)

Set oMirroringGroup = oDiscoveryData.CreateClassInstance("$MPElement[Name='Microsoft.SQLServer.2008.Mirroring.Group']$")
With oMirroringGroup
.AddProperty "$MPElement[Name='System!System.Entity']/DisplayName$", "'" &amp; sDBName &amp; "' database mirror"

.AddProperty "$MPElement[Name='Microsoft.SQLServer.2008.Mirroring.Group']/MirroringGUID$", sMirroringGUID
End With
Call oDiscoveryData.AddInstance(oMirroringGroup)

Set oRelationship = oDiscoveryData.CreateRelationshipInstance("$MPElement[Name='Microsoft.SQLServer.2008.Mirroring.GroupContainsWitness']$")
oRelationship.Source = oMirroringGroup
oRelationship.Target = oWitnessInstance
Call oDiscoveryData.AddInstance(oRelationship)
End If
oResults.MoveNext
Loop

Set oResults = Nothing
cnADOConnection.Close
DoWitnessDiscovery = SQL_DISCOVERY_SUCCESS
End Function
</Script></ScriptBody>
<TimeoutSeconds>$Config/TimeoutSeconds$</TimeoutSeconds>
</DataSource>
</MemberModules>
<Composition>
<Node ID="DS"/>
</Composition>
</Composite>
</ModuleImplementation>
<OutputType>System!System.Discovery.Data</OutputType>
</DataSourceModuleType>