Internet scaling in a PUB/SUB ENS

A method of delivering event notifications to a plurality of event consumers connected to a subscription manager via a wide area network, the method comprising:

• (a) receiving at the subscription manager subscription information identifying at least one topic to which an event consumer intends to subscribe;
• at least one delivery address to which the event notifications will be delivered;
• and delivery information that determines how the event notifications will be delivered;
• (b) receiving at the subscription manager an event notification assigned to a topic;
• (c) identifying a set of the plurality of event consumers that have subscribed to the topic;
• and
• (d) routing the event notification from the subscription manager to the set of the plurality of event consumers, in accordance with subscription information.

A hierarchical server system for distributing event notifications to subscribing event consumers, the hierarchical server configuration comprising:

• a first child server that contains a first list of topics subscribed to by event consumers coupled to the first child server;
• a second child server that contains a second list of topics subscribed to by event consumers coupled to the second child server;
• and
• a parent server coupled to the first child server and the second child server and that includes a referral filtering engine that filters event notifications according to the first list and the second list.

A method of routing event notifications to a plurality of subscribers, comprising the steps of:

• (1) receiving from each of the plurality of subscribers subscription information that includes, for each respective subscriber, a topic to which the respective subscriber intends to receive corresponding event notifications from;
• at least one delivery address to which the event notifications will be delivered;
• and delivery information that determines how the event notifications will be delivered;
• (2) assigning the subscription information for each respective subscriber to one of a plurality of hierarchically arranged subscription managers in a wide area network on the basis of the subscription information;
• (3) receiving an event notification and correlating the event notification to one of a plurality of topics;
• and
• (4) transmitting the event notification through the plurality of hierarchically arranged subscription managers to subscribers that have subscribed to the one topic correlated in step (3).

A method of routing event notifications to a plurality of subscribers, comprising the steps of:

• (1) receiving from each of the plurality of subscribers subscription information that includes, for each respective subscriber, a topic to which the respective subscriber intends to receive corresponding event notifications from;
• at least one delivery address to which the event notifications will be delivered;
• and delivery information that determines how the event notifications will be delivered;
• (2) assigning the subscription information for each respective subscriber to one of a plurality of hierarchically arranged subscription managers in a wide area network on the basis of the subscription information;
• (3) receiving an event notification and correlating the event notification to one of a plurality of topics;
• (4) transmitting the event notification through the plurality of hierarchically arranged subscription managers to subscribers such that some event notifications are transmitted to a set of subscribers who have not subscribed to the event notifications;
• and
• (5) filtering event notifications at the set of subscribers in accordance with subscription information of the set of subscribers.