A node is a host or server computer upon which one or more components have been installed.
A cluster consists of two or more nodes, that work together as a single, continuously available system to provide application management, device management, and data access to users. Each node on a cluster is a fully functional part of the unwired system. However, in a clustered environment, the nodes work together to provide increased availability and performance.
Unwired Platform network topologies use nodes to show the relationships and connections between hardware and component pairings so that communication channels can more readily be graphed. Those connections show how mobile data moves from one node of a network to the next.
There are different node strategies you can employ, depending on the environment you are designing:
| Strategy | Description | Used for |
|---|---|---|
| Single-node | A nonredundant architecture consisting of an Unwired Server and data tier installed on a single host. This strategy is typically used by personal developer licenses. | Personal development or trial installations |
| 2-node | A primitive architecture without load balancing that may optionally use a relay server. The data tier (which includes the CDB, the messaging database, and the monitoring database) is on one node and the application and server tier (which includes Unwired Server, Sybase Control Center, and optionally Afaria) is on another. | Enterprise development or test environments |
| 3-node cluster | A simple redundant architecture with two server tier nodes (which includes Unwired Server, Sybase Control Center, and optionally Afaria) and one data tier node. For an example of this cluster, see Systems Design > Fault-Tolerant Production Environments > Redundant Architecture Options. | Entry-level production environments |
| N+2-node cluster | An optimally redundant architecture with any number of server tier nodes (which includes Unwired Server, Sybase Control Center, and optionally Afaria) supported by a relay server and two data tier nodes. For an example of this cluster, see Systems Design > Fault-Tolerant Production Environments > Redundant Architecture Options. | Full-scale or optimized production environments |