IISGraceFullSessionMonitor

WaitForSessions.ps1

#Get the open requests being handled by IIS
$req = Get-WebRequest

while ($req.Count -gt 0)
{
    #Wait if there are some
    Write-Host "Waiting for request, current inflight: " $req.Count
    Start-Sleep -Seconds 2
    #Check again for sessions
    $req = Get-WebRequest
}

Write-Host "No Sessions on Box, lets update!"

## Do your stopping here, iisreset /stop etc

WaitForSessionsAspNet.ps1

#WaitForSessionsAspNet.ps1
$ErrorActionPreference = "Stop"


#Used to get active sessions for a given set of app domains
function Get-ActiveConnections
{
    Param(
        [string[]]$instanceId
    )

    if (-not $instanceId)
    {
        throw "Instance ID required"
    }

    $results = $instanceId `
        | %{ Get-Counter -Counter "\asp.net applications($_)\sessions active" } `
        | Select -First 1 -ExpandProperty CounterSamples `
        | Measure-Object -Property CookedValue -Sum `
        | Select -ExpandProperty Sum
        

    Write-Host "Aggregated value for active sessions: " $results
    return $results
}

#Use to get the InstanceName for App Domains hosted in a particular website. 
#N.B Relies on Get-Websites and Get-WebAppDomain commands which require the webadministration module to be installed. 
function Get-PerfCounterInstanceNameForSite
{
    Param(
        [string]$siteName
    )

    if (-not $siteName)
    {
        throw "siteName required"
    }

    $website = Get-Website | where { $_.Name -eq $siteName }
    
    if ($website.Length -ne 1)
    {
        throw "Failed to find site"
    }

    $appDomain = Get-WebAppDomain `
        | where { $_.siteId -eq $website.id } `
        | Select -ExpandProperty id `
        | ForEach-Object { $_ -replace "/", "_" } `

    if ($appDomain.Length -lt 1)
    {
        Write-Host "App Domain for the site is not running, probably hasn't been hit recently by a request"
        return $null
    }

    return $appDomain
}

#Script starts here

#Get instance names contained in the website. This is an array as one site can contain multiple app domains
$instanceIds = Get-PerfCounterInstanceNameForSite "Default Web Site"

#If there are no app domains for the site stop 
if (-not $instanceIds)
{
    Write-Host "App Domain isn't running for the site so there are no sessions"
    return
}

#Get the number of active sessions for those app domain instances
$numberOfActiveSess = Get-ActiveConnections $instanceIds

#Loop while still active
while ($numberOfActiveSess -gt 0)
{
    #Wait
    Write-Host "Waiting for request, current inflight: " $numberOfActiveSess
    Start-Sleep -Seconds 10
    #Update to see if session count has dropped
    $numberOfActiveSess = Get-ActiveConnections $instanceIds
}

Write-Host "Requests Drained from Machine"