PLANNING
HCL Domino® supports clustering of calendars and the Free Time database. When clustered, the scheduling system works a little differently behind the scenes than when it is not clustered. However, these differences are not noticeable to users.
When not in a cluster, each server contains a database that includes scheduling information for all users who use that server as their mail server. This database is named busytime.nsf and is known as the Free Time database. In a cluster, there is a single Free Time database for everyone whose mail server is in the cluster. This database is named clubusy.nsf, and it contains all the information that was in all the Free Time databases on all the servers in the cluster. Every server in the cluster contains a replica of this database.
When you add a server to the cluster, the Schedule Manager deletes the busytime.nsf database on that server and creates the clubusy.nsf database, which then replicates with the other servers in the cluster. When a user in the cluster looks for free time, the server looks in its own clubusy.nsffirst to find information for every user in the cluster. For users whose mail servers are outside the cluster, a request is sent to those servers for the free time information. When a user outside the cluster makes a request for information about a user in the cluster, the request fails over to another server in the cluster if the user's mail server is unavailable. Whenever there is a change to clubusy.nsf on any server in the cluster, the Cluster Replicator replicates the change to the other servers in the cluster.
When you remove a server from a cluster, the Schedule Manager deletes clubusy.nsf from that server and creates busytime.nsf on the server. The Schedule Manager on each server in the cluster removes the deleted information from its replica of clubusy.nsf.
Parent topic: How Domino clustering works
Related reference Calendars and scheduling