SqlMemory: Allow setting of dynamic value for min server memory #1397

CHANGELOG.md

@@ -5,6 +5,43 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- SqlSetup
+  - The helper function `Connect-SqlAnalysis` was using `LoadWithPartial()`
+    to load the assembly _Microsoft.AnalysisServices_. On a node where multiple
+    instances with different versions of SQL Server (regardless of features)
+    is installed, this will result in the first assembly found in the
+    GAC will be loaded into the session, not taking versions into account.
+    This can result in an assembly version being loaded that is not compatible
+    with the version of SQL Server it was meant to be used with.
+    A new method of loading the assembly _Microsoft.AnalysisServices_ was
+    introduced under a feature flag; `'AnalysisServicesConnection'`.
+    This new functionality depends on the [SqlServer](https://www.powershellgallery.com/packages/SqlServer)
+    module, and must be present on the node. The [SqlServer](https://www.powershellgallery.com/packages/SqlServer)
+    module can be installed on the node by leveraging the new DSC resource
+    `PSModule` in the [PowerShellGet](https://www.powershellgallery.com/packages/PowerShellGet/2.1.2)
+    module (v2.1.2 and higher). This new method does not work with the
+    SQLPS module due to the SQLPS module does not load the correct assembly,
+    while [SqlServer](https://www.powershellgallery.com/packages/SqlServer)
+    module (v21.1.18080 and above) does. The new functionality is used
+    when the parameter `FeatureFlag` is set to `'AnalysisServicesConnection'`.
+    This functionality will be the default in a future breaking release.
+  - Under a feature flag `'AnalysisServicesConnection'`. The detection of
+    a successful connection to the SQL Server Analysis Services has also been
+    changed. Now it actually evaluates the property `Connected` of the returned
+    `Microsoft.AnalysisServices.Server` object. The new functionality is used
+    when the parameter `FeatureFlag` is set to `'AnalysisServicesConnection'`.
+    This functionality will be the default in a future breaking release.
+
+### Added
+
+- SqlMemory
+  - Added two new optional parameters MinMemoryPercent and MaxMemoryPercent.
+    Provides the ability to set the minimum and/or maximum buffer pool used by
+    the SQL Server instance as a percentage of total server memory.
+    ([issue #1397](https://github.com/dsccommunity/SqlServerDsc/issues/1397)).
+
 ## [15.1.1] - 2021-02-12
 
 ### Fixed

RequiredModules.psd1

@@ -29,5 +29,6 @@
     PSDscResources              = '2.12.0.0'
     StorageDsc                  = '4.9.0.0'
     NetworkingDsc               = '7.4.0.0'
+    PowerShellGet               = '2.1.2'
 }
 

source/DSCResources/DSC_SqlMemory/DSC_SqlMemory.psm1

@@ -85,10 +85,18 @@ function Get-TargetResource
         This is the minimum amount of memory, in MB, in the buffer pool used by
         the instance of SQL Server.
 
+    .PARAMETER MinMemoryPercent
+        This is the minimum amount of memory, as a percentage of total server memory, in the buffer pool used by
+        the instance of SQL Server.
+
     .PARAMETER MaxMemory
         This is the maximum amount of memory, in MB, in the buffer pool used by
         the instance of SQL Server.
 
+    .PARAMETER MaxMemoryPercent
+        This is the maximum amount of memory, as a percentage of total server memory, in the buffer pool used by
+        the instance of SQL Server.
+
     .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.
@@ -123,10 +131,20 @@ function Set-TargetResource
         [System.Int32]
         $MinMemory,
 
+        [Parameter()]
+        [ValidateRange(1, 100)]
+        [System.Int32]
+        $MinMemoryPercent,
+
         [Parameter()]
         [System.Int32]
         $MaxMemory,
 
+        [Parameter()]
+        [ValidateRange(1, 100)]
+        [System.Int32]
+        $MaxMemoryPercent,
+
         [Parameter()]
         [System.Boolean]
         $ProcessOnlyOnActiveNode
@@ -151,6 +169,12 @@ function Set-TargetResource
                         New-InvalidArgumentException -ArgumentName 'MaxMemory' -Message $errorMessage
                     }
 
+                    if ($MaxMemoryPercent)
+                    {
+                        $errorMessage = $script:localizedData.MaxMemoryPercentParamMustBeNull
+                        New-InvalidArgumentException -ArgumentName 'MaxMemoryPercent' -Message $errorMessage
+                    }
+
                     $MaxMemory = Get-SqlDscDynamicMaxMemory
 
                     Write-Verbose -Message (
@@ -159,21 +183,56 @@ function Set-TargetResource
                 }
                 else
                 {
-                    if (-not $MaxMemory)
+                    if (-not $MaxMemory -and -not $MaxMemoryPercent)
                     {
                         $errorMessage = $script:localizedData.MaxMemoryParamMustNotBeNull
                         New-InvalidArgumentException -ArgumentName 'MaxMemory' -Message $errorMessage
                     }
                 }
 
-                Write-Verbose -Message (
-                    $script:localizedData.MaximumMemoryLimited -f $InstanceName, $MaxMemory
-                )
+                if ($MaxMemory)
+                {
+                    if ($MaxMemoryPercent)
+                    {
+                        $errorMessage = $script:localizedData.MaxMemoryPercentParamMustBeNull
+                        New-InvalidArgumentException -ArgumentName 'MaxMemoryPercent' -Message $errorMessage
+                    }
 
-                $sqlServerObject.Configuration.MaxServerMemory.ConfigValue = $MaxMemory
+                    $sqlServerObject.Configuration.MaxServerMemory.ConfigValue = $MaxMemory
+
+                    Write-Verbose -Message (
+                        $script:localizedData.MaximumMemoryLimited -f $InstanceName, $MaxMemory
+                    )
+                }
+                elseif ($MaxMemoryPercent)
+                {
+                    $MaxMemory = Get-SqlDscPercentMemory -PercentMemory $MaxMemoryPercent
+
+                    $sqlServerObject.Configuration.MaxServerMemory.ConfigValue = $MaxMemory
+
+                    Write-Verbose -Message (
+                        $script:localizedData.MaximumMemoryLimited -f $InstanceName, $MaxMemory
+                    )
+                }
 
                 if ($MinMemory)
                 {
+                    if ($MinMemoryPercent)
+                    {
+                        $errorMessage = $script:localizedData.MinMemoryPercentParamMustBeNull
+                        New-InvalidArgumentException -ArgumentName 'MinMemoryPercent' -Message $errorMessage
+                    }
+
+                    $sqlServerObject.Configuration.MinServerMemory.ConfigValue = $MinMemory
+
+                    Write-Verbose -Message (
+                        $script:localizedData.MinimumMemoryLimited -f $InstanceName, $MinMemory
+                    )
+                }
+                elseif ($MinMemoryPercent)
+                {
+                    $MinMemory = Get-SqlDscPercentMemory -PercentMemory $MinMemoryPercent
+
                     $sqlServerObject.Configuration.MinServerMemory.ConfigValue = $MinMemory
 
                     Write-Verbose -Message (
@@ -238,10 +297,18 @@ function Set-TargetResource
         This is the minimum amount of memory, in MB, in the buffer pool used by
         the instance of SQL Server.
 
+    .PARAMETER MinMemoryPercent
+        This is the minimum amount of memory, as a percentage of total server memory, in the buffer pool used by
+        the instance of SQL Server.
+
     .PARAMETER MaxMemory
         This is the maximum amount of memory, in MB, in the buffer pool used by
         the instance of SQL Server.
 
+    .PARAMETER MaxMemoryPercent
+        This is the maximum amount of memory, as a percentage of total server memory, in the buffer pool used by
+        the instance of SQL Server.
+
     .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.
@@ -276,10 +343,20 @@ function Test-TargetResource
         [System.Int32]
         $MinMemory,
 
+        [Parameter()]
+        [ValidateRange(1, 100)]
+        [System.Int32]
+        $MinMemoryPercent,
+
         [Parameter()]
         [System.Int32]
         $MaxMemory,
 
+        [Parameter()]
+        [ValidateRange(1, 100)]
+        [System.Int32]
+        $MaxMemoryPercent,
+
         [Parameter()]
         [System.Boolean]
         $ProcessOnlyOnActiveNode
@@ -346,6 +423,12 @@ function Test-TargetResource
                     New-InvalidArgumentException -ArgumentName 'MaxMemory' -Message $errorMessage
                 }
 
+                if ($MaxMemoryPercent)
+                {
+                    $errorMessage = $script:localizedData.MaxMemoryPercentParamMustBeNull
+                    New-InvalidArgumentException -ArgumentName 'MaxMemoryPercent' -Message $errorMessage
+                }
+
                 $MaxMemory = Get-SqlDscDynamicMaxMemory
 
                 Write-Verbose -Message (
@@ -354,13 +437,26 @@ function Test-TargetResource
             }
             else
             {
-                if (-not $MaxMemory)
+                if (-not $MaxMemory -and -not $MaxMemoryPercent)
                 {
                     $errorMessage = $script:localizedData.MaxMemoryParamMustNotBeNull
                     New-InvalidArgumentException -ArgumentName 'MaxMemory' -Message $errorMessage
                 }
             }
 
+            if ($MaxMemory)
+            {
+                if ($MaxMemoryPercent)
+                {
+                    $errorMessage = $script:localizedData.MaxMemoryPercentParamMustBeNull
+                    New-InvalidArgumentException -ArgumentName 'MaxMemoryPercent' -Message $errorMessage
+                }
+            }
+            elseif ($MaxMemoryPercent)
+            {
+                $MaxMemory = Get-SqlDscPercentMemory -PercentMemory $MaxMemoryPercent
+            }
+
             if ($MaxMemory -ne $currentMaxMemory)
             {
                 Write-Verbose -Message (
@@ -370,8 +466,21 @@ function Test-TargetResource
                 $isServerMemoryInDesiredState = $false
             }
 
-            if ($MinMemory)
+            if ($MinMemory -or $MinMemoryPercent)
             {
+                if ($MinMemory)
+                {
+                    if ($MinMemoryPercent)
+                    {
+                        $errorMessage = $script:localizedData.MinMemoryPercentParamMustBeNull
+                        New-InvalidArgumentException -ArgumentName 'MinMemoryPercent' -Message $errorMessage
+                    }
+                }
+                elseif ($MinMemoryPercent)
+                {
+                    $MinMemory = Get-SqlDscPercentMemory -PercentMemory $MinMemoryPercent
+                }
+
                 if ($MinMemory -ne $currentMinMemory)
                 {
                     Write-Verbose -Message (
@@ -447,3 +556,34 @@ function Get-SqlDscDynamicMaxMemory
     $maxMemory
 }
 
+<#
+    .SYNOPSIS
+        This function returns the amount of memory in MB, calculated from the input percentage of total server memory.
+
+    .PARAMETER MemoryPercent
+        This is the percentage of total server memory to calculate.
+#>
+function Get-SqlDscPercentMemory
+{
+    [CmdletBinding()]
+    param
+    (
+        [Parameter(Mandatory = $true)]
+        [ValidateRange(1, 100)]
+        [System.Int32]
+        $PercentMemory
+    )
+
+    try
+    {
+        $physicalMemory = (Get-CimInstance -ClassName Win32_ComputerSystem).TotalPhysicalMemory
+        $memoryInMegaBytes = [Math]::Round(($physicalMemory * ($PercentMemory/100)) / 1MB)
+    }
+    catch
+    {
+        $errorMessage = $script:localizedData.ErrorGetPercentMemory
+        New-InvalidOperationException -Message $errorMessage -ErrorRecord $_
+    }
+
+    $memoryInMegaBytes
+}

source/DSCResources/DSC_SqlMemory/DSC_SqlMemory.schema.mof

@@ -7,6 +7,8 @@ class DSC_SqlMemory : OMI_BaseResource
     [Write, Description("If set to `$true` then max memory will be dynamically configured. When this parameter is set to `$true`, the parameter **MaxMemory** must be set to `$null` or not be configured. Default value is `$false`.")] Boolean DynamicAlloc;
     [Write, Description("Minimum amount of memory, in MB, in the buffer pool used by the instance of _SQL Server_.")] SInt32 MinMemory;
     [Write, Description("Maximum amount of memory, in MB, in the buffer pool used by the instance of _SQL Server_.")] SInt32 MaxMemory;
+    [Write, Description("Minimum amount of memory, as a percentage of total server memory, in the buffer pool used by the instance of _SQL Server_.")] SInt32 MinMemoryPercent;
+    [Write, Description("Maximum amount of memory, as a percentage of total server memory, in the buffer pool used by the instance of _SQL Server_.")] SInt32 MaxMemoryPercent;
     [Write, Description("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.")] Boolean ProcessOnlyOnActiveNode;
     [Read, Description("Returns if the current node is actively hosting the _SQL Server_ instance.")] Boolean IsActiveNode;
 };

source/DSCResources/DSC_SqlMemory/en-US/DSC_SqlMemory.strings.psd1

@@ -1,15 +1,18 @@
 ConvertFrom-StringData @'
     GetMemoryValues = Getting the current values for minimum and maximum SQL server memory for instance '{0}'.
     SetNewValues = Setting the minimum and maximum memory that will be used by the instance '{0}'.
-    MaxMemoryParamMustBeNull = The parameter MaxMemory must be null when the parameter DynamicAlloc is set to true.
-    MaxMemoryParamMustNotBeNull = The parameter MaxMemory must not be null when the parameter DynamicAlloc is set to false.
+    MaxMemoryParamMustBeNull = The parameter MaxMemory must be null when the parameter DynamicAlloc is set to true or MaxMemoryPercent has a value.
+    MaxMemoryPercentParamMustBeNull = The parameter MaxMemoryPercent must be null when the parameter DynamicAlloc is set to true or MaxMemory has a value.
+    MaxMemoryParamMustNotBeNull = One of the parameters MaxMemory or MaxMemoryPercent must not be null when the parameter DynamicAlloc is set to false.
+    MinMemoryPercentParamMustBeNull = The parameter MinMemoryPercent must be null when the parameter MinMemory has a value.
     DynamicMaxMemoryValue = Dynamic maximum memory has been calculated to {0}MB.
     MaximumMemoryLimited = Maximum memory used by the instance '{0}' has been limited to {1}MB.
     MinimumMemoryLimited = Minimum memory used by the instance '{0}' has been set to {1}MB.
     DefaultValues = Resetting to the default values; MinMemory = {0}, MaxMemory = {1}.
     ResetDefaultValues = Minimum and maximum server memory values used by the instance {0} has been reset to the default values.
     AlterServerMemoryFailed = Failed to alter the server configuration memory for {0}\\{1}.
     ErrorGetDynamicMaxMemory = Failed to calculate dynamically the maximum memory.
+    ErrorGetPercentMemory = Failed to calculate percentage of memory.
     EvaluatingMinAndMaxMemory = Determines the values of the minimum and maximum memory server configuration option for the instance '{0}'.
     NotActiveNode = The node '{0}' is not actively hosting the instance '{1}'. Will always return success for this resource on this node, until this node is actively hosting the instance.
     WrongMaximumMemory = Current maximum server memory used by the instance is {0}MB, but expected {1}MB.

source/DSCResources/DSC_SqlSetup/DSC_SqlSetup.psm1

@@ -342,7 +342,7 @@ function Get-TargetResource
         $getTargetResourceReturnValue.ASSvcAccountUsername = $serviceAnalysisService.UserName
         $getTargetResourceReturnValue.AsSvcStartupType = $serviceAnalysisService.StartupType
 
-        $analysisServer = Connect-SQLAnalysis -ServerName $sqlHostName -InstanceName $InstanceName
+        $analysisServer = Connect-SQLAnalysis -ServerName $sqlHostName -InstanceName $InstanceName -FeatureFlag $FeatureFlag
 
         $getTargetResourceReturnValue.ASCollation = $analysisServer.ServerProperties['CollationName'].Value
         $getTargetResourceReturnValue.ASDataDir = $analysisServer.ServerProperties['DataDir'].Value
@@ -2505,36 +2505,6 @@ function Get-InstalledSharedFeatures
     return $sharedFeatures
 }
 
-<#
-    .SYNOPSIS
-        Test if the specific feature flag should be enabled.
-
-    .PARAMETER FeatureFlag
-        An array of feature flags that should be compared against.
-
-    .PARAMETER TestFlag
-        The feature flag that is being check if it should be enabled.
-#>
-function Test-FeatureFlag
-{
-    [CmdletBinding()]
-    [OutputType([System.Boolean])]
-    param
-    (
-        [Parameter()]
-        [System.String[]]
-        $FeatureFlag,
-
-        [Parameter(Mandatory = $true)]
-        [System.String]
-        $TestFlag
-    )
-
-    $flagEnabled = $FeatureFlag -and ($FeatureFlag -and $FeatureFlag.Contains($TestFlag))
-
-    return $flagEnabled
-}
-
 <#
     .SYNOPSIS
         Get current properties for the feature SQLENGINE.

source/DSCResources/DSC_SqlSetup/README.md

@@ -145,9 +145,10 @@ more feature flags can be added to the parameter `FeatureFlag`, i.e.
 >from one release to another, including having breaking changes.
 
 <!-- markdownlint-disable MD013 -->
-Flag | Description
+Feature flag | Description
 --- | ---
-\- | -
+DetectionSharedFeatures | A new way of detecting if the shared features is installed or not. This was implemented because the previous implementation did not work fully with SQL Server 2017.
+AnalysisServicesConnection | A new method of loading the assembly *Microsoft.AnalysisServices*. Using this, no longer is the helper function `Connect-SqlAnalysis` using `LoadWithPartial()` to load the assembly **Microsoft.AnalysisServices**. This requires the [SqlServer module](https://www.powershellgallery.com/packages/SqlServer) to be present on the node.
 <!-- markdownlint-enable MD013 -->
 
 ## Known issues