There are two general deployment topologies for the middle tier of the SAS Intelligence
Platform: single server (which results in a homogeneous
cluster) and multiple server (which results in a heterogeneous cluster). Many deployments
default to single server topology, unless the default is overridden in the corresponding
SAS Deployment Wizard custom prompting level. By default, some SAS products trigger
the multiple server topology when they are included in the plan.
Single server topology
results in clustered nodes that all contain the same applications
that can be clustered. Conversely, multiple server topology results
in specific applications being deployed to different server instances.
Each server instance can be clustered independently, providing the
ability to allocate additional resources to the applications and application
groups that are more heavily used.
Note: Whether the single or multiple
server topology is selected, both vertical and horizontal clusters
are still possible, as is a combination of both clustering techniques.
The only difference is the manner in which the applications are distributed
to the server instances.