IS-Notifier Clause Samples

IS-Notifier. The IS-Notifier is the gCube Service dedicated to manage subscriptions with respect to Topics, i.e. organised items of interest for publishing/subscription [43]. It acts as a subscriptions broker since allows its client to subscribe to a topic while freeing them from the need to know the location of the notifications producer (i.e. its EPR). It also supports subscriptions to Topics that are not yet exposed by their producers. In this case, the IS-Notifier maintains a subscription in a pending state until the notification producer registers the related Topic. It is important to notice that the design of such a service does not implement the classical brokered notification schema since the IS-Notifier subscribes the consumer directly to the notification producer. In this way, there is no single service that is in charge to receive notifications from producers and then dispatch them to the subscribed client(s). However, the IS-Notifier plays a mediator role because of the subscriptions brokerage. In fact, the IS-Notifier automatically manages the relocation of notification producers by forwarding the client subscription requests to the new instances of the producers. Moreover, the service supports the transparent subscription/re-subscription of the client to the new producer instances that comes up after the initial request of subscription.