The Connection Pool

The connection pool is an object inside the client that is responsible for maintaining the current list of nodes. Theoretically, nodes are either dead or alive.

However, in the real world, things are never so clear. Nodes are sometimes in a gray-zone of "probably dead but not confirmed", "timed-out but unclear why" or "recently dead but now alive".

The connection pool’s job is to manage this set of unruly connections and try to provide the best behavior to the client. There are several connection pool implementations that you can choose from: