CMS is actually the XDS database, it has the information of Topology, Configuration and Policies.
CMS operates in a single master/multiple replica system.
In every Lync Server deployment there can only one master CMS and all servers running Lync Server have a local replica of CMS. i.e. RTCLocal Instance
The way to modify information in CMS is by using one of the tools: Topology Builder, Lync power Shell and CSCP.
Lync Server will always read from the local replica.
All updates to information in CMS takes place at the master. The information is then replicated to all replicas via the File Share defined in the topology, it has a folder "Central Mgmt" inside it this is the structure
So, this was the file share, now each Lync server has a local “xds-replica” folder located under \\Lync server FQDN\ and this is how the structure looks
So, any changes made to XDS database is then gets written in a .xml file which is then made as data.zip and placed in the file share and finally to the replica, The replica upon getting the file it commits the changes in its local XDS database and a confirmation is sent to the Master CMS
Services responsible for CMS replication
- Lync Server Master Replicator Agent (MASTER) - If change is found in the master CMS, thechangeis written in Data.zip and it is copied to each “to-replica” folder
- Lync Server File Transfer Agent (FTA) - once it sees a data.zip file in them it start the replication process
And after the replication once it sees status.zip file it pull it to the “from-replica” folder on the CMS-Master
- Lync Server Replica Replicator Agent (REPLICA). - once it sees a data.zip file in it, it unpack it and apply the changes to the server
Each 60 seconds a task run to check if there is any changes made to the CMS master that need to be replicated.
If changes are found (xml files), they are all packed in a Data.zip and it is copied to each
“to-replica” folder of each server’s replica folder in the xds-master directory
The FTA service running on the Master once it sees a data.zip file in them it start the replication process
On the servers themselves, the Replica replicator is monitoring the “from-master” folder, once it sees a data.zip file in it, it unpack it and apply the changes to the server
After the changes are applied, a status.zip file is created and placed in the “to-master” folder in the server.
FTA is monitoring “to-master” folders on all Lync Servers and once it sees status.zip file it pull it to the “from-replica” folder on the CMS-Master
The Master replicator then unpack the package and update the status CMS-Master
For Edge: Lync edge server uses the replication web services over HTTPS / 4443 port to copy the Data.zip file, the replication web services uses the internal Certificate issued by the internal CA and trusted by the Lync in the replication process.
monitor all “to-replica” folders and once it sees a data.zip file in them it start the replication process
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