Storage area network methods and apparatus with coordinated updating of topology representation

A digital data processing apparatus of the type that manages a SAN includes a first queue with entries representing tasks and a second queue with entries representing data that correspond to those tasks. Data in the second queue is grouped in accord with the task to which they correspond. A manager service updates the internal representation of the SAN (e.g., the representation of the SAN topology) by executing the tasks in the first queue one at a time, for example, atomically using a single-threaded process.