Cache Topologies


Coherence supports many different cache topologies, but generally they fall into a few general categories. Because Coherence uses the TCMP clustering protocol, Coherence can supports each of these without compromise. However, there are inherent advantages of each topology, and trade-offs between them.

Topology as a concept refers to where the data physically resides and how it is accessed in a distributed environment. It is important to understand that, regardless of where the data physically resides, and which topology is being used, every cluster participant has the same logical view of the data, and uses the same exact API to access the data. Generally, this means that the topology can be tuned or even selected at deployment time.

The extent of the cluster and of its tiers is fully definable in the tangosol-coherence.xml configuration file. This includes the ability to lock down the set of servers that can access and manage the cache for security purposes. The selection of which topology to use is typically driven by the cache configuration file, which by default is named coherence-cache-config.xml; however, the topology can also be driven entirely by the Coherence programmatic API, if the developer so chooses.