A system comprising: an event notification system comprising: at least one processor; and a memory (1906, 1908) on which is stored machine readable instructions that are to cause the at least one processor to: receive a notification indicating creation of an event subscription based on an input received from a subscriber; invoke an event source to enable publishing of events corresponding to an event topic associated with the event subscription, the event source being an event hubs service; receive a response from the event source for publishing of the events; on receiving the response, forward a targeted event notification to the subscribers; and upon deletion of the event subscription, send information regarding the deletion of the event subscription to the event source; and the event source, configured to: determine, upon receiving the information regarding the deletion of the event subscription, whether the event subscription is the last remaining event subscription for the event topic; and stop publishing events if it is determined that the deleted event subscription is the last remaining event subscription for the event topic. an event notification system comprising: at least one processor; and a memory (1906, 1908) on which is stored machine readable instructions that are to cause the at least one processor to: receive a notification indicating creation of an event subscription based on an input received from a subscriber; invoke an event source to enable publishing of events corresponding to an event topic associated with the event subscription, the event source being an event hubs service; receive a response from the event source for publishing of the events; on receiving the response, forward a targeted event notification to the subscribers; and upon deletion of the event subscription, send information regarding the deletion of the event subscription to the event source; and at least one processor; and a memory (1906, 1908) on which is stored machine readable instructions that are to cause the at least one processor to: receive a notification indicating creation of an event subscription based on an input received from a subscriber; invoke an event source to enable publishing of events corresponding to an event topic associated with the event subscription, the event source being an event hubs service; receive a response from the event source for publishing of the events; on receiving the response, forward a targeted event notification to the subscribers; and upon deletion of the event subscription, send information regarding the deletion of the event subscription to the event source; and receive a notification indicating creation of an event subscription based on an input received from a subscriber; invoke an event source to enable publishing of events corresponding to an event topic associated with the event subscription, the event source being an event hubs service; receive a response from the event source for publishing of the events; on receiving the response, forward a targeted event notification to the subscribers; and upon deletion of the event subscription, send information regarding the deletion of the event subscription to the event source; and the event source, configured to: determine, upon receiving the information regarding the deletion of the event subscription, whether the event subscription is the last remaining event subscription for the event topic; and stop publishing events if it is determined that the deleted event subscription is the last remaining event subscription for the event topic. determine, upon receiving the information regarding the deletion of the event subscription, whether the event subscription is the last remaining event subscription for the event topic; and stop publishing events if it is determined that the deleted event subscription is the last remaining event subscription for the event topic.