Connection pools are groups of open data connections that can be allocated to users (the user's Stratum.Viewer role) as they need to connect to data in the Stratum.Connector Analysis Services database. For example, connections are needed when someone builds a view, runs a view, or creates or edits a role. When a user requires a connection, it is taken from the pool and allocated to that user's role. The pool will create new open connections as its connections become allocated until the pool reaches its specified maximum number of open connections. Allocated connections are returned to a pool and become open connections again when a user no longer needs them – such as when a user signs off. If the pool has reached its maximum number of open connections, the allocated connection will simply be disconnected and removed instead of being accepted back into the pool. The pool continues this pattern of reusing connections unless a connection becomes unsuitable for use. For example, if a connection fails and becomes a dead connection or an open connection has not been used (allocated) in a while and reaches its timeout point. The pool will disconnect and remove such connections.
Note: Open connections are also known as free or unused connections.