Allow a named Pool to be used with the GemFire 'ClusteredSpringSessions' Client Region

[jxblum]

When using GemFire support in Spring Session to back and manage an (HTTP) Session, particularly when using the client/server topology, it is possible that the user may have specified multiple GemFire Pools in her Spring configuration on the client.

This is a useful GemFire feature that allows the user to route certain types of requests (e.g. Session requests) to specific GemFire Servers in the cluster, which have been "grouped" accordingly. GemFire Servers can have an associated "Server Group".

When there exists multiple Pools in the GemFire cache client configuration, the user may want to specify which Pool the Spring Session Data GemFire "ClusteredSpringSessions" Region should route Session requests to. Therefore, this enhancement will add a poolName attribute to the@EnableGemFireHttpSession annotation.

The reason this will be a String-based attribute as opposed to an object, or anything else, is that Spring Data GemFire, and subsequently GemFire's API itself for creating the (client) Region (i.e. "ClusteredSpringSessions") expects the "name" of the Pool (see here). The corresponding Spring Data GemFire API is here.

While the SDG ClientRegionFactoryBean does have a pool property, this would require "qualification" on the Pool object in the presence of multiple Pools defined in the Spring context.