functions/Enable-DbaTraceFlag.ps1

function Enable-DbaTraceFlag {
    <#
        .SYNOPSIS
            Enable Global Trace Flag(s)
 
        .DESCRIPTION
            The function will set one or multiple trace flags on the SQL Server instance(s) listed
 
        .PARAMETER SqlInstance
            Allows you to specify a comma separated list of servers to query.
 
        .PARAMETER SqlCredential
            Login to the target instance using alternative credentials. Windows and SQL Authentication supported. Accepts credential objects (Get-Credential)
 
        .PARAMETER TraceFlag
            Trace flag number(s) to enable globally
 
        .PARAMETER EnableException
            By default, when something goes wrong we try to catch it, interpret it and give you a friendly warning message.
            This avoids overwhelming you with "sea of red" exceptions, but is inconvenient because it basically disables advanced scripting.
            Using this switch turns this "nice by default" feature off and enables you to catch exceptions with your own try/catch.
 
        .NOTES
            Tags: TraceFlag
            Author: Garry Bargsley (@gbargsley), http://blog.garrybargsley.com
 
            Website: https://dbatools.io
            Copyright: (C) Chrissy LeMaire, clemaire@gmail.com
            License: MIT https://opensource.org/licenses/MIT
 
        .LINK
            https://dbatools.io/Enable-DbaTraceFlag
 
        .EXAMPLE
            PS C:\> Enable-DbaTraceFlag -SqlInstance sql2016 -TraceFlag 3226
 
            Enable the trace flag 3226 on SQL Server instance sql2016
 
        .EXAMPLE
            PS C:\> Enable-DbaTraceFlag -SqlInstance sql2016 -TraceFlag 1117, 1118
 
            Enable multiple trace flags on SQL Server instance sql2016
    #>

    [CmdletBinding()]
    param (
        [parameter(Position = 0, Mandatory, ValueFromPipeline)]
        [Alias("ServerInstance", "SqlServer", "SqlServers")]
        [DbaInstanceParameter[]]$SqlInstance,
        [PSCredential]$SqlCredential,
        [parameter(Mandatory)]
        [int[]]$TraceFlag,
        [Alias('Silent')]
        [switch]$EnableException
    )

    process {
        foreach ($instance in $SqlInstance) {
            Write-Message -Level Verbose -Message "Connecting to $instance"
            try {
                $server = Connect-SqlInstance -SqlInstance $instance -SqlCredential $SqlCredential
            }
            catch {
                Stop-Function -Message "Failure" -Category ConnectionError -ErrorRecord $_ -Target $instance -Continue
            }

            $CurrentRunningTraceFlags = Get-DbaTraceFlag -SqlInstance $server -EnableException

            # We could combine all trace flags but the granularity is worth it
            foreach ($tf in $TraceFlag) {
                $TraceFlagInfo = [PSCustomObject]@{
                    SourceServer = $server.ComputerName
                    InstanceName = $server.ServiceName
                    SqlInstance  = $server.DomainInstanceName
                    TraceFlag    = $tf
                    Status       = $null
                    Notes        = $null
                    DateTime     = [DbaDateTime](Get-Date)
                }
                if ($CurrentRunningTraceFlags.TraceFlag -contains $tf) {
                    $TraceFlagInfo.Status = 'Skipped'
                    $TraceFlagInfo.Notes = "The Trace flag is already running."
                    $TraceFlagInfo
                    Write-Message -Level Warning -Message "The Trace flag [$tf] is already running globally."
                    continue
                }

                try {
                    $query = "DBCC TRACEON ($tf, -1)"
                    $server.Query($query)
                    $server.Refresh()
                }
                catch {
                    $TraceFlagInfo.Status = "Failed"
                    $TraceFlagInfo.Notes = $_.Exception.Message
                    $TraceFlagInfo
                    Stop-Function -Message "Failure" -ErrorRecord $_ -Target $server -Continue
                }
                $TraceFlagInfo.Status = "Successful"
                $TraceFlagInfo
            }
        }
    }
}