CODEWITHSUNDEEP
powershellreporting-services
Jay
Jay

Reputation: 465

Powershell - simply checking if a function completed successfully or not (times out)

I basically have this simple powershell script that executes an ssrs report url and saves it to the network.

It usually runs fine, but sometimes it times out and when it does, it still says it succeeded. I've tried a handful of things with no luck.

A simplified version of my script looks like this:

-----------------------------
function RunReport($url,$outputfile) {
# // create a request
[Net.HttpWebRequest] $req = [Net.WebRequest]::create($url)
$req.Method = "GET"
$req.Timeout = 600000 # = 10 minutes

# // Set credentials
$req.UseDefaultCredentials = $true

#echo  "Getting Response"
[Net.HttpWebResponse] $result = $req.GetResponse()
[IO.Stream] $stream = $result.GetResponseStream()

#[IO.StreamReader] $reader = New-Object IO.StreamReader($stream)
[System.IO.FileStream]$writeStream = New-Object System.IO.FileStream($outputfile, [System.IO.FileMode]::Create);

# // write to file
[byte[]]$buffer = new-object byte[] 4096
[int]$total = [int]$count = 0
do
{
 $count = $stream.Read($buffer, 0, $buffer.Length)
 $writeStream.Write($buffer, 0, $count)
} while ($count -gt 0)
$writeStream.Close()
#$stream.flush()
$stream.Close()
}


$url=...
$outputfile=...

IF(RunReport "$url" "$outputfile")
{Write-Host "Success"}
ELSE
{Write-Host "Failed"}
-------------------------------

I've tried stuff like this with no luck:

RunReport "$url" "$outputfile"
If($?)
    {Write-Host "Success"}
ELSE
    {Write-Host "Failed"}

and

RunReport "$url" "$outputfile"
If($? -eq true)
    {Write-Host "Success"}
ELSE
    {Write-Host "Failed"}

The timeout error I'm dealing with is:

Exception calling "GetResponse" with "0" argument(s): "The operation has timed out" At C:\data\powershell\script.ps1:9 char:49 + [Net.HttpWebResponse] $result = $req.GetResponse <<<< () + CategoryInfo : NotSpecified: (:) [], MethodInvocationException + FullyQualifiedErrorId : DotNetMethodException

You cannot call a method on a null-valued expression. At C:\data\powershell\script.ps1:10 char:48 + [IO.Stream] $stream = $result.GetResponseStream <<<< () + CategoryInfo : InvalidOperation: (GetResponseStream:String) [], RuntimeException + FullyQualifiedErrorId : InvokeMethodOnNull

You cannot call a method on a null-valued expression. At C:\data\powershell\script.ps1:18 char:38 + $count = $stream.Read <<<< ($buffer, 0, $buffer.Length) + CategoryInfo : InvalidOperation: (Read:String) [], RuntimeException + FullyQualifiedErrorId : InvokeMethodOnNull

You cannot call a method on a null-valued expression. At C:\data\powershell\script.ps1:23 char:14 + $stream.Close <<<< () + CategoryInfo : InvalidOperation: (Close:String) [], RuntimeException + FullyQualifiedErrorId : InvokeMethodOnNull

Any help would be greatly appreciated. I assume this should be fairly easy, just don't have the correct syntax ? Thanks

Upvotes: 0

Views: 2756

Answers (3)

Adil Hindistan
Adil Hindistan

Reputation: 6605

Maybe you can use try/catch to deal with that part like this:

try {
 [Net.HttpWebResponse] $result = $req.GetResponse() 
}

catch {
 return 1
}

You can apply the same technique in other places where you suspect code is not doing what it is supposed to do like:

try { 
[System.IO.FileStream]$writeStream = New-Object System.IO.FileStream($outputfile, [System.IO.FileMode]::Create);
}

catch {
 return 1
}

Once you detect where the issue is happening, you could then look into exception like

catch { write-warning $_ ; exit 1 }

Upvotes: 1

alroc
alroc

Reputation: 28144

You have two problems:

  1. The timeouts (and the cascading errors from that)

  2. Your RunReport function doesn't ever return anything.

For #2, you can't test something that doesn't exist. So make your function return some kind of success/fail indicator to the caller.

For #1, when you call GetResponse() you need to wrap it in a try/catch block, catch the exception, and exit the function with the appropriate status returned to the caller.

You might want to look at this SO post about calling SSRS using SOAP methods as well.

Upvotes: 0

jbsmith
jbsmith

Reputation: 1666

The 'cannot call a method on a null-valued expression' errors are all stemming from the fact that the .GetResponse method is failing with a timeout, leaving the $result variable unassigned. The simplest change would be to put the rest of the script (after "$result = $req.GetResponse()") into an "if ($result) {}" block. You can then use a "then {}" block to do your error handling.

A more advanced method would be to use try {} and catch {} blocks, to catch the actual timeout exception and handle it properly.

Upvotes: 0

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