Force an IIS app pool to stop

Powershell to aggressively force an IIS web worker process (w3wp) to stop.  Useful when you need to manually de-pool a web node in a hurry, but you have a long running process in the app pool that prevents the process from stopping using "stop-service".

The AppPoolName parameter allows you to select the specific w3wp.exe based on the app pool name (they're difficult to tell apart in script).  The script could be extended to return a status when the app pool name isn't found.

Usage is Kill-AppPool -AppPoolName name_of_application


[CmdletBinding()]
param (
    [Parameter(Mandatory=$True)] [string] $AppPoolName
)

function Kill-AppPool([string]$name="*"){
    $list = get-process w3wp
    foreach($p in $list){ 
        $filter = "Handle='" + $p.Id + "'"
        $wmip = get-WmiObject Win32_Process -filter $filter 

        if($wmip.CommandLine -match "-ap `"([a-zA-Z0-9`.]+)`""){
            $appName = $matches[1]
            $p | add-member NoteProperty AppPoolName $appName
        }
    }

    $filtererList = ($list | where { $_.AppPoolName -like $name })
    if($filtererList.Count -gt 1){ throw "'$name' matched more than one appPools.  You must enter a unique name." }

    taskkill /F /PID $filtererList.Id

    return $filtererList.Id
}

Kill-AppPool $AppPoolName