ExecuteQueryWithExponentialRetry.ps1

Function ExecuteQueryWithExponentialRetry
{
	Param (
		[Microsoft.SharePoint.Client.ClientContext]$ctx
	)
	
	return ExecuteQueryWithExponentialRetryInternal $ctx 3 1000
}

Function ExecuteQueryWithExponentialRetryInternal
{
	Param (
		[Microsoft.SharePoint.Client.ClientContext]$ctx,
		[int]$retryCount,
		[int]$delayMs
	)
	
	$retryAttempts = 0
	$backoffInterval = $delayMs
	
	if ($retryCount -lt 1)
	{
		Throw [System.IO.ArgumentException] "Provide a retry count greater than zero."
	}
	if ($delayMs -lt 1)
	{
		Throw [System.IO.ArgumentException] "Provide a delay greater than zero."
	}

	while ($retryAttempts -lt $retryCount)
	{
		try
		{	
			$result = $ctx.ExecuteQuery()
			return $result
		}
		catch [System.Net.WebException]
		{
			# Check if response was throttled
			$statusCode = 0
			if(($_.Exception -ne $null) -and ($_.Exception.Response -ne $null))
			{
				$statusCode = [int]([System.Net.HttpWebResponse]$_.Exception.Response).StatusCode
			}
			if($statusCode -eq 429)
			{
				Write-Host ""
				Write-Host "Request throttled, waiting $backoffInterval milliseconds..." -F Yellow -NoNewLine
				
				[System.Threading.Thread]::Sleep($backoffInterval)
				
				$retryAttempts++
				$backoffInterval = $backoffInterval * 2
			}
			else
			{
				# If not throttled then throw
				Throw $_
			}
		}
	}
	
	Throw "ExecuteQueryWithExponentialRetry, failed to execute query"
}