Hi Tom,

One thing I always do for any Umbraco deployment is call a few of the urls on the site before doing the swap, so the process would be something like:

• Deploy new site to the slot (making sure all the App_Data is cleared)
• Ping a few of the urls (e.g. root/home, and whatever the major listing pages are)
• check your pings get 200 responses in an acceptable time frame
• swap the slots

Pinging the site in the deployment slot before you swap the slots makes sure the site is 'warmed up' (cache is built, examine indexes rebuilt, etc) and should mean a proper 0 downtime deployment.

Hope this helps!

Euan

Hi Euan,

I forgot to include that in my initial question, but we deploy via and Azure Pipeline and the last step pauses until we warm up the pre-deployment slot.

It's now got me thinking whether the way we warm up the slot might be an issue. I tend to hit a dozen or so different specific pages (each with different doctypes) and I do this one at a time, while others in the team may use a script which hits all the pages at once in different Chrome tabs.

I'll look into that a bit further.

thanks t

Hey Tom,

They way I do it is to have a powershell script that hits the endpoints so you can automate the warmup + swapping (or not).

This one is for Octopus Deploy, so you may need to tweak the way the variables are passed in, but it should get you most of the way there:

// Start Script
    $ErrorActionPreference = "Stop" 
function Get-Parameter($Name, $Default, [switch]$Required) {
    $result = $null

if ($OctopusParameters -ne $null) {
    $result = $OctopusParameters[$Name]
}

if ($result -eq $null) {
    if ($Required) {
        throw "Missing parameter value $Name"
    } else {
        $result = $Default
    }
}

Write-Verbose "Get-Parameter for '$($Name)' [value='$($result)' default='$($Default)']"

    return $result
}
function HandleError($message) {
    if (!$whatIf) {
        throw $message
    } else {
        Write-Host $message -Foreground Yellow
    }
}

Function Invoke-UrlWarmup{
    param(
        [Parameter(Mandatory=$true)]
        [string] $url,
        [Parameter(Mandatory=$true)]
        [int] $maxResponseMilliseconds
    )

Write-Host "Requesting $url until response time less than $maxResponseMilliseconds and with response code Ok(200)"

$warmedUp = 0

Do {
    $statusCode = -1
    $timeInMs = 9999999999
    $time = Measure-Command {
        $response = Invoke-WebRequest $url -UseBasicParsing

        $statusCode = $response.StatusCode
    }

    $timeInMs = $time.TotalMilliseconds

    if ($statusCode -ne 200){
        Write-Host "Request responded with $statusCode - trying request again" -ForegroundColor Cyan
        continue
    }

    if ($timeInMs -gt $maxResponseMilliseconds){
        Write-Host "Response time $timeInMs greater than maximum threshold: $maxResponseMilliseconds - trying request again" -ForegroundColor Cyan
        continue
    }

    # All criteria passed
    Write-Host "Url "$url" resonded within all criteria:"
    Write-Host "Respons Code: 200"
    Write-Host "Request response time ($timeInMs) within threshold of $maxResponseMilliseconds milliseconds"
    Write-Host "*****************"
    Write-Host ""

    $warmedUp = 1

} While ($warmedUp -eq 0)

}

$websiteDomain = Get-Parameter "websiteDomain" -Required
$urls = Get-Parameter "urls" -Required
$maxResponseMilliseconds = Get-Parameter "maxResponseMilliseconds" -Required

Write-Host "Doing website warmup on $websiteDomain"

$urlList = $urls.Split(",")

foreach ($url in $urlList) {
    [System.UriBuilder] $uriBuilder = [System.UriBuilder]::new($websiteDomain)
    $uriBuilder.Path = $url

    $fullUrl = $uriBuilder.Uri.AbsoluteUri

    Invoke-UrlWarmup -url $fullUrl -maxResponseMilliseconds 

$maxResponseMilliseconds
}

Write-Host "All urls successfully warmed up" -ForegroundColor Green


    // End Script

hope this helps, Euan

(Please exuse the formatting)

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