Powershell makes AD replication status monitoring trivial

Powershell is making monitoring various components much easier than in previous versions of Windows without third party tools.

A great example of this is Active Directory replication. With 15 sites to keep track of I run these commands on a schedule task every 15 mins to create a handy text file on the desktop of the state of AD replication.
repadmin /replsum > replsum.txt
repadmin /showrepl > showrepl.txt

So if there are any issues I can get a quick overview of the summary and detail state of AD replication.

But what I am really interested in knowing is when there is an active directory replication failure for further investigation. This can be achieved and eg emailed in a timely fashion very easily in a few lines of Powershell.
The commands below run repadmin and put the results into an array, then parse the array looking for lines with errors by seeing if the lines are longer in length than lines having no error text. Not pretty but it works well. Note the code -like *dc* which only checks lines with the letters dc contained in them and ignoring any other lines. If all your domain controllers have some other naming convention you would need to change that.


$replsumerror = $false
$arrayreplsum = repadmin /replsum
for($i = 0; $i -le $arrayreplsum.length -1; $i++) {if(($arrayreplsum[$i].length -gt 57) -and ($arrayreplsum[$i] -like "*dc*" )) {$replsumerror = $true}}

if ($replsumerror -eq $true) ...do some event  - eg email


I add this Powershell script on a 15 minute scheduled task and we get easy AD replication monitoring.


I have been disappointed with new Server 2012 Get-ADReplicationFailure cmdlet as it always returns the last error, which could be seconds or years ago. It could do with an option to show only 'current errors'
in a similar fashion to the repadmin /replsum /errorsonly switch or something similar.