url's availability

Question

How to detemine the url's availability until it gets status code 200 after number of retries

Answer 1

You're resetting $counter to 1 as part of the do/while loop. It will always be less than 6.

You can't reference $Response.Statuscode if you set $Response to an exception value in your catch statements.

I don't understand what you are trying to do on the first 5 loops.

I simplified your code. See if this works.

 Set-StrictMode -Version Latest
 $user = "test"
 $pass = "test"
 $baseUrl = "https://test.cloudapp.azure.com"

 function Get-RootWebStatus($baseUrl) {
    $KeepLooking = $true                       # Should we continue to retry?
    $counter = 1                               # How many times we've tried
    $RetryLimit = 5                            # Max number of retries 
    $SleepInterval = 5                         # How long to sleep between retries 
    $StartTime = Get-Date                      # When we started 
    while ($KeepLooking) {
        write-output "$(Get-Date -format 'g') - Querying $baseUrl to see if available."
        try { 
            $response = Invoke-WebRequest $baseUrl 
            write-output "$(Get-Date -format 'g') - Web request status: $($Response.Statuscode)"
            if ($Response.Statuscode -eq 200) {
                write-output "$(Get-Date -format 'g') - Web site is alive!"
                $KeepLooking = $false
                continue 
            }
        } 
        catch { 
            write-output "$(Get-Date -format 'g') - Error! $($_.Exception.Message)"      
        }
     -  $counter++  | Out-Null
        if ($counter -gt $RetryLimit) {
            write-output "$(Get-Date -format 'g') - RetryLimit exceeded. Giving up.."
            $KeepLooking = $false
            continue
        }
        start-sleep $SleepInterval 
    }
    write-output "$(Get-Date -format 'g') - Execution time was $((New-TimeSpan -start $StartTime -end (Get-Date)).seconds) seconds"  
}  

   Get-RootWebStatus $baseUrl

Answer 2

How about this?

function Get-RootWebStatus($baseUrl) {
    $sleepfor = 1
    $counter = 1
    $maxretries = 5
    do { 
        try { 
            $response = Invoke-WebRequest $baseUrl -ErrorAction STOP
            if ($Response.StatusCode -eq 200){
                $Response.StatusCode
                Break                               # avoid the Start-Sleep
            }
        }
        catch {
            if ($counter -gt ($maxretries - 1)){    # if it fails this many times just return the status and quit
                if ($_.Exception.Response.SttusCode.Value__){
                    $_.Exception.Response.StatusCode.Value__
                }
                else {
                    $_.Exception.Message
                }
                Break
                # as an alternate just return, say, a -1 and Break instead of showing a message
                # -1
                # Break
            }
        }
        Start-Sleep -s $sleepfor
        $sleepfor *= 2                  # adjust as you feel necessary
        $counter++
    } While ($Response.Statuscode -ne 200 -and $counter -le $maxretries)
}

Get-RootWebStatus 'ibm.com/gibberish'       # 404
Get-RootWebStatus 'ibmxyz.com'              # The remote name could not be resolved: 'ibmxyz.com'
Get-RootWebStatus 'ibm.com'                 # returns 200

Answer 3

I see the "Write-Host" results. But the "Write-Output" results are emitted to the "Success" stream and returned to the caller of your Get-SubUrlResponse function.

Also, not all the code for the function is presented. The "do" is missing the closing "}", as is the function. And, there's nothing to show what the function's caller does with the output returned to it (which is where the "execution time" strings should be handled)!

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