Constructing a report server farm requires an appropriate number of node licenses for each planned cluster within the farm.
Each of the primary nodes within every cluster manages the number and type of nodes that can join the cluster based on the nodes license. Contact your software vendor for details about the nodes licenses.
Only the report servers containing such a node license are capable of becoming primary nodes for their cluster. Remember that report servers that do not meet the licensing criteria are not displayed in the farm creation wizard for the primary node selection step and cannot be selected as the primary node.
For example, a report server containing the license for seven nodes can be used to create a primary node for a cluster and as a result, this report server will allow up to six new nodes to be attached to its cluster. Each of the report server types require their own licensing. For example, a CAS acting as a primary server and containing four node licenses will allow only three more CAS report servers to be attached to that cluster. No other type of report server will be allowed to join. If that CAS node license contained the ADS licenses, for example two, that primary server would allow for three additional CAS instances and two additional ADS instances to be attached to that cluster.
Because the CAS report server is capable of managing both the CAS and the ADS licenses within the cluster, we recommend that you start creating a cluster by selecting the CAS a primary server for your new cluster. Make sure that, if you plan to attach additional servers to the cluster, the primary node for that cluster should contain enough licenses for both CAS and ADS to support your future expansion.