Error Trapping of Redundant Event in 4 minute Window with PowerSell - sql

Question

I have a script that successfully traps an application event using a SQL query in the database. If found - it will write to the event log and sent an email to support team. Now the team wants to have a double check within a four minute window. You may get ErrorA & ErrorD twice - and ErrorB & ErrorC do not reoccur.
How would you do an internal check within the 1st loop. So first time you have ErrorA.1st and second check two minutes later you see ErrorA.1st = ErrorA.2nd, therefore send off a email?
while($true) ### Endless loop - continuely looking for ERRORS to trap for two actions below (Write event log and send email)
{
$connString = "data source=sqlservername,1433;Initial catalog=HugsDB;Integrated Security=True;"
$date= $((get-date).AddSeconds(-120).ToString("MM-dd-yyyy HH:mm:ss"))
$QueryText = "select statement that graps all errors $date"
#SETUP SQL VALUES####
$SqlConnection = new-object System.Data.SqlClient.SqlConnection
$SqlConnection.ConnectionString = $connString
$SqlCommand = $SqlConnection.CreateCommand()
$SqlCommand.CommandText = $QueryText
#### query the database
$DataAdapter = new-object System.Data.SqlClient.SqlDataAdapter $SqlCommand
$dataset = new-object System.Data.Dataset
$rowCount = $DataAdapter.Fill($dataset)
$sqlConnection.Close()
$sqlConnection.Dispose()
#### IF QUERY FINDS ERRORS # exact time of query ( could be 1 or more devices reporting an error ) write an event log message & send team an email
if($rowCount -gt 0) {
### assign a unique variable to each unique error on 1st find.
ForEach ($row in $dataset.Tables[0].Rows) {
[int]$incre = 0
$row.exciter_name = $incre.$row.exciter_name
}
## sleep 2 minutes before checking to see if we have a repeat of any of the finds in second query
Start-Sleep -Seconds 120
## Another query used to see if a reoccurance of same error.
## If the same error occurs send email and write error to event log.
if($rowCount -gt 0) {
ForEach ($row in $dataset.Tables[0].Rows) {
## NOT SURE HOW TO DO A CHECK TO LOOK FOR REOCCURANCE TO GENERATE EVENT.
write-Eventlog -LogName Exciter_Log -Source Exciter_Health –EventID 108 -Message "PACE Exciter Health Alert"
Send-MailMessage -smtpserver "$SMTPServer" -from "$EmailFrom" -to "$EmailTo" -subject "$Subject" -bodyAsHtml "$Body" -credential $anonCredentials
#################################################################################################################################################
#Second BREAK
Start-Sleep -Seconds 120
}

Answer 1

Sounds like you need to keep track of your previous message and compare them with the new messages. I'm assuming from the code that it does not matter which error message is actually repeated, but only that one is. In the example below what I've done is capture all unique messages in a variable called $currentErrors. Once done with capturing the messages you'll want to check if any of these previous errors appear in in this current set. If even one repeat error is found the the $alert flag is set to true and performs your error handling. Last it moves all current error messages into previous error message to be checked on the next run.
$currentErrors = #()
$alert = $false
if ($rowCount -gt 0)
{
foreach ($row in $dataset.Tables[0].Rows)
{
# not sure what these 2 lines do?
[int]$incre = 0
$row.exciter_name = $incre.$row.exciter_name
if ($currentErrors -notcontains $row.exciter_name) { $currentErrors += $row.exciter_name } # add error message to $currentErrors if not already added
}
# on first run previousErrors will be null so this foreach will do nothing
foreach ($error in $previousErrors)
{
if ($currentErrors -contains $error)
{
# previous error found in current errors
$alert = $true
break # exit loop once duplicate error is found
}
}
if ($alert)
{
Write-EventLog -LogName Exciter_Log -Source Exciter_Health –EventID 108 -Message "PACE Exciter Health Alert"
Send-MailMessage -smtpserver "$SMTPServer" -from "$EmailFrom" -to "$EmailTo" -subject "$Subject" -bodyAsHtml "$Body" -credential $anonCredentials
}
# move currentErrors into previousErrors for next loop
$previousErrors = $currentErrors
Start-Sleep -Seconds 120
}