Delivering messages from message sources to subscribing recipients

A system configured to deliver messages respectively generated by a message source to at least one recipient that is assigned to a message server, respective recipients subscribing to at least one message source, the system comprising:

• a message store configured to store messages;
• a recipient profile store configured to store recipient profiles identifying the message sources subscribed by respective recipients;
• a subscription filter indicating, for respective message sources, whether at least one recipient subscribes to the message source;
• a message receiving component configured to, upon receiving a message from a message source:
• examine the subscription filter to determine whether at least one recipient subscribes to the message source, and
• upon determining that at least one recipient subscribes to the message source:
• store the message in the message store, and
• associate with the message the recipients subscribing to the message source;
• and
• a message presenting component configured to, upon receiving from a recipient a receive request to receive messages:
• retrieve from the message store at least zero retrieved messages associated with the recipient, and
• present the retrieved messages to the recipient.

A computer-readable storage medium comprising instructions that, when executed on a processor of a message server of a message server set, the message server having a processor and a message store, deliver messages respectively generated by a message source to at least one recipient that is assigned to the message server, respective recipients assigned to a message server in the message server set based on a predicted shared set of message sources subscribed by the recipients, respective recipients having a recipient profile identifying the message sources subscribed by the recipient, and the message servers of the message server set sharing an assignment map indicating an assignment of respective recipients to a message server in the message server set, by:

• upon joining the message server set:
• generating a subscription filter comprising a bloom filter and indicating, for respective message sources, whether at least one recipient subscribes to the message source;
• and
• sending the subscription filter to at least one second message server of the message server set;
• upon receiving a subscribe request from a recipient to subscribe to a message source:
• updating the recipient profile of the recipient to identify the message source subscribed by the recipient, and
• updating the subscription filter by inserting the message source into the bloom filter to indicate that at least one recipient subscribes to the message source;
• upon receiving an unsubscribe request from a recipient to unsubscribe from a message source:
• updating the recipient profile of the recipient to identify the message source not subscribed by the recipient, and
• regenerating the bloom filter based on the recipient profiles of the message server;
• upon receiving a removal request to remove a recipient from the message server:
• removing the recipient profile of the recipient, and
• regenerating the bloom filter based on the recipient profiles of the message server;
• upon receiving the add request to add the new recipient to the message server:
• identifying a recipient message server for which the new recipient may share a predicted shared set of message sources with the recipients assigned to the recipient message server;
• if the recipient message server comprises the message server:
• generating a new recipient profile identifying the message sources subscribed by the new recipient, and
• updating the assignment map indicating an assignment of the new recipient to the message server;
• and
• if the recipient message server does not comprise the message server, forwarding the add request to the recipient message server;
• upon generating the subscription filter, sending the subscription filter to at least one other message server of the message server set;
• upon identifying at least one shared message source subscribed by a first recipient hosted by the message server and a second recipient hosted by a second message server, sending to the second message server a transfer request to transfer the second recipient to the message server;
• upon receiving a transfer request to transfer a recipient from the message server to a second message server:
• sending the recipient profile of the recipient to the second message server;
• removing the recipient profile from the message server;
• updating the subscription filter;
• and
• updating the assignment map indicating the assignment of the recipient to the second message server;
• upon receiving a second subscription filter from a second message server, storing the second subscription filter of the second message server;
• upon receiving a message from a message source, for respective second subscription filters:
• examining the subscription filter to determine whether at least one recipient subscribes to the message source;
• upon determining that at least one recipient subscribes to the message source:
• storing the message in the message store, and
• associating with the message the recipients subscribing to the message source;
• examining the second subscription filter to determine whether at least one recipient assigned to the second message server subscribes to the message source;
• and
• upon determining that at least one recipient assigned to the second message server subscribes to the message source, forwarding the message to the second message server;
• upon receiving from a recipient a receive request to receive messages:
• using the assignment map, identifying a recipient message server to which the recipient is assigned;
• if the recipient message server comprises the message server:
• retrieving from the message store at least zero retrieved messages associated with the recipient, and
• presenting the retrieved messages to the recipient;
• and
• if the recipient message server does not comprise the message server, forwarding the receive request to the recipient message server;
• and
• upon leaving the message server set:
• for respective recipients assigned to the message server, transferring the recipient to another message server of the message server set;
• and
• requesting at least one second message server of the message server set to remove the subscription filter for the message server.