ConnectionPool::SpecificPool currently limits the maximum number of connections that can concurrently be established to a single host at a time (maxPendingConnections). However, there is no such limit on the total number of connections that can concurrently be established across all hosts/SpecificPool instances that a given ConnectionPool is associated with. Such a limit could be useful for more gracefully handling network disruption events where connections to a large number of hosts will be need to be re-established, such as when an RSM needs to begin re-monitoring a large sharded cluster.