Lync installs a local SQL Express instance on each Lync server called “RTCLOCAL”. This database is used to hold a replica of the CMS database. Anytime a configuration change is made in Lync, the changes get replicated from the CMS to all the local replicas on each server.
If you have set up a trusted application in Lync, like integration with Outlook Web App (OWA) or Group Chat, you will notice within the Topology view of the Lync Control Panel that a red X appears next to those servers. By default, Lync assumes that all servers in the Topology will have a local CMS replica.
You can also view this status by running: Get-CsManagementStoreReplicationStatus
These servers do not have a RTCLOCAL instance and therefore do not need to be part of the replication cycle. There are two options to disable replication for these trusted applications (my example will show disabling replication for the integration with OWA):
Option 1: Topology Builder
Open the Topology Builder and navigate to the Trusted Application Servers node. Here we see that replication is enabled for this application:
Right-click on the object and select Edit Properties… Now uncheck the box labeled “Enable replication of configuration data to this pool”
Click OK and then publish the topology.
Option 2: Command Shell
Open the Lync Management Shell and run: Get-CsTrustedApplicationPool
Here we see that the parameter –RequiresReplication is set to True.
To disable, run the following command:
Set-CsTrustedApplicationPool –Identity TrustedApplicationPool:webmail.twhlab.com –RequiresReplication $False
Now when opening the Topology node within the Control Panel shows an “N/A” instead of a red X: