functions/Test-DbaMaxDop.ps1
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Function Test-DbaMaxDop { <# .SYNOPSIS Displays information relating to SQL Server Max Degree of Paralellism setting. Works on SQL Server 2005-2016. .DESCRIPTION Inspired by Sakthivel Chidambaram's post about SQL Server MAXDOP Calculator (https://blogs.msdn.microsoft.com/sqlsakthi/p/maxdop-calculator-sqlserver/), this script displays a SQL Server's: max dop configured, and the calculated recommendation. For SQL Server 2016 shows: - Instance max dop configured and the calculated recommendation - max dop configured per database (new feature) More info: https://support.microsoft.com/en-us/kb/2806535 https://blogs.msdn.microsoft.com/sqlsakthi/2012/05/23/wow-we-have-maxdop-calculator-for-sql-server-it-makes-my-job-easier/ These are just general recommendations for SQL Server and are a good starting point for setting the "max degree of parallelism" option. THIS CODE IS PROVIDED "AS IS", WITH NO WARRANTIES. .PARAMETER SqlServer Allows you to specify a comma separated list of servers to query. .PARAMETER SqlCredential Allows you to login to servers using SQL Logins as opposed to Windows Auth/Integrated/Trusted. To use: $cred = Get-Credential, this pass this $cred to the param. Windows Authentication will be used if DestinationSqlCredential is not specified. To connect as a different Windows user, run PowerShell as that user. .NOTES Author : Cláudio Silva (@claudioessilva) Requires: sysadmin access on SQL Servers dbatools PowerShell module (https://dbatools.io, clemaire@gmail.com) Copyright (C) 2016 Chrissy LeMaire This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. .LINK https://dbatools.io/Test-DbaMaxDop .EXAMPLE Test-DbaMaxDop -SqlServer sql2008, sqlserver2012 Get Max DOP setting for servers sql2008 and sqlserver2012 and also the recommended one. .EXAMPLE Test-DbaMaxDop -SqlServer sql2014 -Detailed Shows Max DOP setting for server sql2014 with the recommended value. As the -Detailed switch was used will also show the 'NUMANodes' and 'NumberOfCores' of each instance .EXAMPLE Test-DbaMaxDop -SqlServer sqlserver2016 -Detailed Get Max DOP setting for servers sql2016 with the recommended value. As the -Detailed switch was used will also show the 'NUMANodes' and 'NumberOfCores' of each instance. Because it is an 2016 instance will be shown 'InstanceVersion', 'Database' and 'DatabaseMaxDop' columns. #> [CmdletBinding()] Param ( [parameter(Position = 0, Mandatory = $true, ValueFromPipeline = $True)] [Alias("ServerInstance", "SqlInstance", "SqlServers")] [string[]]$SqlServer, [System.Management.Automation.PSCredential]$SqlCredential, [Switch]$Detailed ) BEGIN { $notesDopLT = "Before changing MaxDop, consider that the lower value may have been intentionally set." $notesDopGT = "Before changing MaxDop, consider that the higher value may have been intentionally set." $notesDopZero = "This is the default setting. Consider using the recommended value instead." $notesDopOne = "Some applications like SharePoint, Dynamics NAV, SAP, BizTalk has the need to use MAXDOP = 1. Please confirm that your instance is not supporting one of these applications prior to changing the MaxDop." $notesAsRecommended = "Configuration is as recommended" $collection = @() } PROCESS { $hasscopedconfiguration = $false foreach ($servername in $sqlserver) { Write-Verbose "Attempting to connect to $servername" try { $server = Connect-SqlServer -SqlServer $servername -SqlCredential $SqlCredential } catch { Write-Warning "Can't connect to $servername or access denied. Skipping." continue } if ($server.versionMajor -lt 9) { Write-Warning "This function does not support versions lower than SQL Server 2005 (v9). Skipping server '$servername'." Continue } #Get current configured value $maxdop = $server.Configuration.MaxDegreeOfParallelism.ConfigValue try { #represents the Number of NUMA nodes $sql = "SELECT COUNT(DISTINCT memory_node_id) AS NUMA_Nodes FROM sys.dm_os_memory_clerks WHERE memory_node_id!=64" $NUMAnodes = $server.ConnectionContext.ExecuteScalar($sql) } catch { $errormessage = $_.Exception.Message.ToString() Write-Warning "Failed to execute $sql.`n$errormessage" continue } try { #represents the Number of Processor Cores $sql = "SELECT COUNT(scheduler_id) FROM sys.dm_os_schedulers WHERE status = 'VISIBLE ONLINE'" $numberofcores = $server.ConnectionContext.ExecuteScalar($sql) } catch { $errormessage = $_.Exception.Message.ToString() Write-Warning "Failed to execute $sql.`n$errormessage" continue } #Calculate Recommended Max Dop to instance #Server with single NUMA node if ($NUMAnodes -eq 1) { if ($numberofcores -lt 8) { #Less than 8 logical processors - Keep MAXDOP at or below # of logical processors $recommendedMaxDop = $numberofcores } else { #Equal or greater than 8 logical processors - Keep MAXDOP at 8 $recommendedMaxDop = 8 } } else #Server with multiple NUMA nodes { if (($numberofcores / $NUMAnodes) -lt 8) { #Less than 8 logical processors per NUMA node - Keep MAXDOP at or below # of logical processors per NUMA node $recommendedMaxDop = [int]($numberofcores / $NUMAnodes) } else { #Greater than 8 logical processors per NUMA node - Keep MAXDOP at 8 $recommendedMaxDop = 8 } } #Setting notes for instance max dop value $notes = $null if ($maxdop -eq 1) { $notes = $notesDopOne } else { if ($maxdop -ne 0 -and $maxdop -lt $recommendedMaxDop) { $notes = $notesDopLT } else { if ($maxdop -ne 0 -and $maxdop -gt $recommendedMaxDop) { $notes = $notesDopGT } else { if ($maxdop -eq 0) { $notes = $notesDopZero } else { $notes = $notesAsRecommended } } } } $collection += [pscustomobject]@{ Instance = $server.Name InstanceVersion = $server.Version Database = "N/A" DatabaseMaxDop = "N/A" CurrentInstanceMaxDop = $maxdop RecommendedMaxDop = $recommendedMaxDop NUMANodes = $NUMAnodes NumberOfCores = $numberofcores Notes = $notes } #since SQL Server 2016, MaxDop can be set per database if ($server.versionMajor -ge 13) { $hasscopedconfiguration = $true Write-Verbose "Server '$server' has an 2016 version, checking each database." foreach ($database in $server.Databases | Where-Object { $_.IsSystemObject -eq $false -and $_.IsAccessible -eq $true }) { Write-Verbose "Checking database '$($database.Name)'." $dbmaxdop = $database.MaxDop $collection += [pscustomobject]@{ Instance = $server.Name InstanceVersion = $server.Version Database = $database.Name DatabaseMaxDop = $dbmaxdop CurrentInstanceMaxDop = $maxdop RecommendedMaxDop = $recommendedMaxDop NUMANodes = $NUMAnodes NumberOfCores = $numberofcores Notes = if ($dbmaxdop -eq 0) { "Will use CurrentInstanceMaxDop value" } else { "$notes" } } } } $server.ConnectionContext.Disconnect() } } END { if ($Detailed) { if ($hasscopedconfiguration) { return ($collection | Select-Object Instance, InstanceVersion, Database, DatabaseMaxDop, CurrentInstanceMaxDop, RecommendedMaxDop, NUMANodes, NumberOfCores, Notes) } else { return ($collection | Select-Object Instance, CurrentInstanceMaxDop, RecommendedMaxDop, NUMANodes, NumberOfCores, Notes) } } else { if ($hasscopedconfiguration) { return ($collection | Select-Object Instance, InstanceVersion, Database, DatabaseMaxDop, CurrentInstanceMaxDop, RecommendedMaxDop, Notes) } else { return ($collection | Select-Object Instance, CurrentInstanceMaxDop, RecommendedMaxDop, Notes) } } } } |