Powershell MSUtil.LogQuery not closing SQL connection - powershell

Question

I've written a PowerShell scrip that iterates through a large number of IIS W3C logfiles and inserts the values into a MSSQL database.
Set-Variable -Name "UnprocessedDir" -Value "X:\files" -Description "Folder for unprocessed log files" Scope Script
Set-Variable -Name "InputObject" -Value (New-Object -comObject MSUtil.LogQuery.IISW3CInputFormat) -Description "Log Parser input COM object" -Scope Script
Set-Variable -Name "OutputObject" -Value (New-Object -comObject MSUtil.LogQuery.SQLOutputFormat) -Description "Log Parser output COM object" -Scope Script
$OutputObject.clearTable = $false
$OutputObject.createTable = $false
$OutputObject.database = "Database_Name"
$OutputObject.driver = "SQL Server"
$OutputObject.dsn = "DSN_Name"
$OutputObject.fixColNames = $true
$OutputObject.ignoreIdCols = $true
$OutputObject.ignoreMinWarns = $true
$OutputObject.maxStrFieldLen = 511
$OutputObject.oConnString = $null
$OutputObject.password = $null
$OutputObject.server = "sqlserver.domain.com\INSTANCENAME"
$OutputObject.transactionRowCount = 5000
$OutputObject.username = $null
Set-Variable -Name "IISLogs" -Value #(Get-ChildItem -Path $UnprocessedDir -Recurse -File) -Description "Array of files to be imported into SQL" -Scope Script
Set-Variable -Name "LPComObj" -Value (New-Object -com MSUtil.LogQuery) -Description "COM Object used to import Log Parser records into MSSQL" -Scope Script
Write-Output "$(Get-ISOTimeStamp) Beginning SQL import. $($IISLogs.Count) Files to be imported"
$IISLogs | ForEach-Object { $loop = 0 } {
Set-Variable -Name "SubDir" -Value $(($_.FullName).Split('\')[-2]) -Description "Subdirectory where log file is located" -Scope Script
Set-Variable -Name "LogType" -Value $(($_.FullName).Split('\')[-3]) -Description "Type of log being imported" -Scope Script
Set-Variable -Name "ServerName" -Value $(($_.FullName).Split('\')[-4]) -Description "ServerName of file being imported" -Scope Script
Set-Variable -Name "LPQuery" -Description "Query to use in Log Parser" -Scope Script -Value #"
SELECT
-- FIELDS LogFilename,LogRow,date,time,c-ip,cs-username,s-sitename,s-computername,s-ip,s-port,cs-method,cs-uri-stem,cs-uri-query,sc-status,sc-substatus,sc-win32-status,sc-bytes,cs-bytes,time-taken,cs-version,cs-host,cs(User-Agent),cs(Cookie),cs(Referer),s-event,s-process-type,s-user-time,s-kernel-time,s-page-faults,s-total-procs,s-active-procs,s-stopped-procs
-- STANDARD FIELDS date,time,s-ip,cs-method,cs-uri-stem,cs-uri-query,s-port,cs-username,c-ip,cs(User-Agent),cs(Referer),sc-status,sc-substatus,sc-win32-status,time-taken
'$($ServerName)' as [servername],
'$($_.Name)' as [filename],
LogRow AS [row],
'$($LogType)' as [logtype],
TO_TIMESTAMP(date,time) AS [timestamp],
[s-ip],
[cs-method],
[cs-uri-stem],
[cs-uri-query],
TO_INT([s-port]),
[cs-username],
[c-ip],
[cs(User-Agent)],
[cs(Referer)],
TO_INT([sc-status]),
TO_INT([sc-substatus]),
TO_INT([sc-win32-status]),
TO_INT([time-taken]),
0 AS lock
INTO IIS_W3C
FROM '$($_.FullName)'
"#
Set-Variable -Name "LPResult" -Value ($LPComObj.ExecuteBatch($LPQuery, $InputObject, $OutputObject)) -Description "IIS Log File imported into SQL" -Scope Script
If ($LPResult -eq $false)
{
Write-Output "$(Get-ISOTimeStamp) Data imported from `"$($_.FullName)`""
Set-Variable -Name "loop" -Value ($loop + 1) -Description "Increase loop iteration Count" -Scope Script
}
Else
{
Write-Output "$(Get-ISOTimeStamp) Log Parser returned errors importing `"$($_.FullName)`""
Throw "$(Get-ISOTimeStamp) Log Parser returned errors importing `"$($_.FullName)`""
}
}
The number of logs I'm importing is tens of thousands; the code above works spectacularly for a few hundred files, but after a few hours, it crashes. From what I can tell, it looks like every iteration of the ForEach-Object loop creates a new SQL TCP connection which is not terminated at the end of the loop.
I've tried creating the $LPComObj both within and outside of the loop. I've tried Remove-Variable. I've tried some generic commands like $LPComObj.Close(), .Remove(), .Quit(), etc. The MSUtil.LogQuery method itself does not seem to contain any methods to close the SQL TCP connection, and as the script is running, I can see more and more TCP connections piling up. I tried a few things using [System.Runtime.Interopservices.Marshal]:: to release/remove the COM object, but none of them closed the TCP connection. Even closing the PowerShell session doesn't kill the connection.
The only way I was able to do this is by hunting down and finding the dllhost.exe" process that was using the ports and killing it. But from within the script, there isn't a clean way to get the PID of the offending dllhost.exe process. (Trying to kludge some variant of Get-Process | Stop-Process might work, but would add a lot of time to the execution of the script.)
What other ways might I be able to work around this problem?