DSCResources/MSFT_xSQLServerMaxDop/MSFT_xSQLServerMaxDop.psm1

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
Import-Module -Name (Join-Path -Path (Split-Path (Split-Path $PSScriptRoot -Parent) -Parent) `
        -ChildPath 'xSQLServerHelper.psm1') `
    -Force
<#
    .SYNOPSIS
    This function gets the max degree of parallelism server configuration option.
 
    .PARAMETER SQLServer
    The host name of the SQL Server to be configured.
 
    .PARAMETER SQLInstanceName
    The name of the SQL instance to be configured.
#>

function Get-TargetResource
{
    [CmdletBinding()]
    [OutputType([System.Collections.Hashtable])]
    param
    (
        [Parameter(Mandatory = $true)]
        [ValidateNotNullOrEmpty()]
        [System.String]
        $SQLInstanceName,

        [Parameter()]
        [ValidateNotNullOrEmpty()]
        [System.String]
        $SQLServer = $env:COMPUTERNAME
    )

    $sqlServerObject = Connect-SQL -SQLServer $SQLServer -SQLInstanceName $SQLInstanceName

    # Is this node actively hosting the SQL instance?
    $isActiveNode = Test-ActiveNode -ServerObject $sqlServerObject

    if ($sqlServerObject)
    {
        Write-Verbose -Message 'Getting the max degree of parallelism server configuration option'
        $currentMaxDop = $sqlServerObject.Configuration.MaxDegreeOfParallelism.ConfigValue
    }

    $returnValue = @{
        SQLInstanceName = $SQLInstanceName
        SQLServer       = $SQLServer
        MaxDop          = $currentMaxDop
        IsActiveNode    = $isActiveNode
    }

    $returnValue
}

<#
    .SYNOPSIS
    This function sets the max degree of parallelism server configuration option.
 
    .PARAMETER SQLServer
    The host name of the SQL Server to be configured.
 
    .PARAMETER SQLInstanceName
    The name of the SQL instance to be configured.
 
    .PARAMETER Ensure
    When set to 'Present' then max degree of parallelism will be set to either the value in parameter MaxDop or dynamically configured when parameter DynamicAlloc is set to $true.
    When set to 'Absent' max degree of parallelism will be set to 0 which means no limit in number of processors used in parallel plan execution.
 
    .PARAMETER DynamicAlloc
    If set to $true then max degree of parallelism will be dynamically configured.
    When this is set parameter is set to $true, the parameter MaxDop must be set to $null or not be configured.
 
    .PARAMETER MaxDop
    A numeric value to limit the number of processors used in parallel plan execution.
 
    .PARAMETER ProcessOnlyOnActiveNode
    Specifies that the resource will only determine if a change is needed if the target node is the active host of the SQL Server Instance.
    Not used in Set-TargetResource.
#>

function Set-TargetResource
{
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory = $true)]
        [ValidateNotNullOrEmpty()]
        [System.String]
        $SQLInstanceName,

        [Parameter()]
        [ValidateNotNullOrEmpty()]
        [System.String]
        $SQLServer = $env:COMPUTERNAME,

        [Parameter()]
        [ValidateSet('Present', 'Absent')]
        [ValidateNotNullOrEmpty()]
        [System.String]
        $Ensure = 'Present',

        [Parameter()]
        [System.Boolean]
        $DynamicAlloc,

        [Parameter()]
        [System.Int32]
        $MaxDop,

        [Parameter()]
        [System.Boolean]
        $ProcessOnlyOnActiveNode
    )

    $sqlServerObject = Connect-SQL -SQLServer $SQLServer -SQLInstanceName $SQLInstanceName

    if ($sqlServerObject)
    {
        Write-Verbose -Message 'Setting the max degree of parallelism server configuration option'
        switch ($Ensure)
        {
            'Present'
            {
                if ($DynamicAlloc)
                {
                    if ($MaxDop)
                    {
                        throw New-TerminatingError -ErrorType MaxDopParamMustBeNull `
                            -FormatArgs @( $SQLServer, $SQLInstanceName ) `
                            -ErrorCategory InvalidArgument
                    }

                    $targetMaxDop = Get-SqlDscDynamicMaxDop -SqlServerObject $sqlServerObject
                    New-VerboseMessage -Message "Dynamic MaxDop is $targetMaxDop."
                }
                else
                {
                    $targetMaxDop = $MaxDop
                }
            }

            'Absent'
            {
                $targetMaxDop = 0
                New-VerboseMessage -Message 'Desired state should be absent - MAXDOP is reset to the default value.'
            }
        }

        try
        {
            $sqlServerObject.Configuration.MaxDegreeOfParallelism.ConfigValue = $targetMaxDop
            $sqlServerObject.Alter()
            New-VerboseMessage -Message "Setting MAXDOP value to $targetMaxDop."
        }
        catch
        {
            throw New-TerminatingError -ErrorType MaxDopSetError `
                -FormatArgs @($SQLServer, $SQLInstanceName, $targetMaxDop) `
                -ErrorCategory InvalidOperation `
                -InnerException $_.Exception
        }
    }
}

<#
    .SYNOPSIS
    This function tests the max degree of parallelism server configuration option.
 
    .PARAMETER SQLServer
    The host name of the SQL Server to be configured.
 
    .PARAMETER SQLInstanceName
    The name of the SQL instance to be configured.
 
    .PARAMETER Ensure
    When set to 'Present' then max degree of parallelism will be set to either the value in parameter MaxDop or dynamically configured when parameter DynamicAlloc is set to $true.
    When set to 'Absent' max degree of parallelism will be set to 0 which means no limit in number of processors used in parallel plan execution.
 
    .PARAMETER DynamicAlloc
    If set to $true then max degree of parallelism will be dynamically configured.
    When this is set parameter is set to $true, the parameter MaxDop must be set to $null or not be configured.
 
    .PARAMETER MaxDop
    A numeric value to limit the number of processors used in parallel plan execution.
 
    .PARAMETER ProcessOnlyOnActiveNode
    Specifies that the resource will only determine if a change is needed if the target node is the active host of the SQL Server Instance.
#>

function Test-TargetResource
{
    [CmdletBinding()]
    [OutputType([System.Boolean])]
    param
    (
        [Parameter(Mandatory = $true)]
        [ValidateNotNullOrEmpty()]
        [System.String]
        $SQLInstanceName,

        [Parameter()]
        [ValidateNotNullOrEmpty()]
        [System.String]
        $SQLServer = $env:COMPUTERNAME,

        [Parameter()]
        [ValidateSet('Present', 'Absent')]
        [ValidateNotNullOrEmpty()]
        [System.String]
        $Ensure = 'Present',

        [Parameter()]
        [System.Boolean]
        $DynamicAlloc,

        [Parameter()]
        [System.Int32]
        $MaxDop,

        [Parameter()]
        [System.Boolean]
        $ProcessOnlyOnActiveNode
    )

    Write-Verbose -Message 'Testing the max degree of parallelism server configuration option'

    $parameters = @{
        SQLInstanceName = $SQLInstanceName
        SQLServer       = $SQLServer
    }

    $currentValues = Get-TargetResource @parameters

    $getMaxDop = $currentValues.MaxDop
    $isMaxDopInDesiredState = $true

    <#
        If this is supposed to process only the active node, and this is not the
        active node, don't bother evaluating the test.
    #>

    if ( $ProcessOnlyOnActiveNode -and -not $getTargetResourceResult.IsActiveNode )
    {
        New-VerboseMessage -Message ( 'The node "{0}" is not actively hosting the instance "{1}". Exiting the test.' -f $env:COMPUTERNAME,$SQLInstanceName )
        return $isMaxDopInDesiredState
    }

    switch ($Ensure)
    {
        'Absent'
        {
            if ($getMaxDop -ne 0)
            {
                New-VerboseMessage -Message "Current MaxDop is $getMaxDop should be updated to 0"
                $isMaxDopInDesiredState = $false
            }
        }
        'Present'
        {
            if ($DynamicAlloc)
            {
                if ($MaxDop)
                {
                    throw New-TerminatingError -ErrorType MaxDopParamMustBeNull `
                        -FormatArgs @( $SQLServer, $SQLInstanceName ) `
                        -ErrorCategory InvalidArgument
                }

                $dynamicMaxDop = Get-SqlDscDynamicMaxDop
                New-VerboseMessage -Message "Dynamic MaxDop is $dynamicMaxDop."

                if ($getMaxDop -ne $dynamicMaxDop)
                {
                    New-VerboseMessage -Message "Current MaxDop is $getMaxDop should be updated to $dynamicMaxDop"
                    $isMaxDopInDesiredState = $false
                }
            }
            else
            {
                if ($getMaxDop -ne $MaxDop)
                {
                    New-VerboseMessage -Message "Current MaxDop is $getMaxDop should be updated to $MaxDop"
                    $isMaxDopInDesiredState = $false
                }
            }
        }
    }

    $isMaxDopInDesiredState
}

<#
    .SYNOPSIS
    This cmdlet is used to return the dynamic max degree of parallelism
#>

function Get-SqlDscDynamicMaxDop
{
    $cimInstanceProc = Get-CimInstance -ClassName Win32_Processor

    # init variables
    $numProcs = 0
    $numCores = 0

    # Loop through returned objects
    foreach ($processor in $cimInstanceProc)
    {
        # increment number of processors
        $numProcs += $processor.NumberOfLogicalProcessors

        # increment number of cores
        $numCores += $processor.NumberOfCores
    }


    if ($numProcs -eq 1)
    {
        $dynamicMaxDop = [Math]::Round($numCores / 2, [System.MidpointRounding]::AwayFromZero)
    }
    elseif ($numCores -ge 8)
    {
        $dynamicMaxDop = 8
    }
    else
    {
        $dynamicMaxDop = $numCores
    }

    $dynamicMaxDop
}

Export-ModuleMember -Function *-TargetResource