Controlling service failover in clustered storage apparatus networks

A controller for use at a node of a clustered computer apparatus comprises an exception detection component for detecting an exception raised by a service component at the node; a quiesce component responsive to the exception detection component for quiescing lease-governed activity by the service component prior to termination of a lease; a lease control component responsive to the quiesce component for pre-expiry relinquishing of the lease; and a communication component responsive to the lease control component for communicating the pre-expiry relinquishing of the lease to one or more further nodes of said clustered computer apparatus. The controller may further comprise a further communication component for receiving a communication indicating the pre-expiry relinquishing of a lease; a further lease control component responsive to the communication to control failure processing; and a further service component to perform a service in place of the service component at the node.