Sending inter-server notifications using an out-of-band communications protocol

• US 7,606,904 B2
• Filed: 07/26/2005
• Issued: 10/20/2009
• Est. Priority Date: 03/30/2005
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Rao, Deepak P., Cox, Shaun D.
• Primary Examiner(s): Etienne; Ario
• Assistant Examiner(s): RUBIN, BLAKE J
• Application Number:
  US11/190,504
• Publication Number:
  US 20060224744A1
• Time in Patent Office: 1,547 Days
• Field of Search: 709/226, 709/227
• US Class Current: 709/226
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30
• CPC Class Codes: H04L 67/54 Presence management, e.g. monitoring or registration for receipt of user log-on information, or the connection status of the users

Abstract

A method and system for sending notifications from servers of a server pool to clients is provided. The notification system determines when an in-band notification is to be sent to clients. The notification system identifies a distinguished server for each client that is to send the in-band notification to that client. The notification system then sends an out-of-band notification to the distinguished server of each client indicating that an in-band notification is to be sent to the client. When the distinguished server receives the out-of-band notification, the distinguished server then sends an in-band notification to the client.

Claims

1. A method in a server pool of servers for sending notifications of presence information to subscribers of presence information of publishers, each server of the server pool for accessing presence-related information via a back-end database server, the back-end database server storing presence information of publishers and subscription information of subscribers, the publishers and subscribers being clients of presence information, the method comprising:

for each client,

receiving at a load balancer for the server pool a logon request from the client; and

upon receiving the logon request from the client,

selecting at the load balancer a server of the server pool to be assigned as being a distinguished server for the client based on number of clients assigned to each server; and

storing by the load balancer at the back-end database server an indication that the selected server has been assigned to be the distinguished server of the client;

receiving at the load balancer an update to presence information of a publisher;

after receiving the update,

determining at the load balancer the distinguished server of the publisher; and

sending from the load balancer to the distinguished server of the publisher an indication of the updated presence information of the publisher;

storing at the back-end database server by the distinguished server of the publisher updated presence information of the publisher;

determining by the distinguished server of the publisher that an in-band notification is to be sent to subscribers to the presence information of the publisher by retrieving from the back-end database server an indication of subscribers to the presence information of the publisher;

identifying by the distinguished server of the publisher a distinguished server for each subscriber to the presence information of the publisher by retrieving from the back-end database server an indication of the distinguished server of each subscriber;

sending from the distinguished server of the publisher an out-of-band notification to each distinguished server of each subscriber, the out-of-band notification indicating that the distinguished server is to send an in-band notification to the subscriber whose distinguished server is that distinguished server, the in-band notification indicating the updated presence information of the publisher so that the distinguished server of a subscriber can send to the subscriber a notification of the updated presence information; and

under control of each distinguished server of each subscriber,

retrieving from the back-end database server, undated presence information of the publisher; and

sending the retrieved undated presence information to the subscriber.

2. The method of claim 1 wherein the in-band notification uses a session initiation protocol and the out-of-band notification uses a remote procedure call protocol.

3. The method of claim 2 wherein both the in-band and out-of-band notifications are encrypted.

4. The method of claim 1 wherein an out-of-band notification identifies multiple clients that are to receive an out-of-band notification and that have the same distinguished server.

5. The method of claim 1 wherein a distinguished server is a server from which a client is to receive all notifications from the server pool.

6. The method of claim 1 wherein the in-band notification uses a session initiation protocol and the out-of-band notification uses a remote procedure call protocol, wherein the notification indicates that presence information of a publisher has been updated, wherein the out-of-band notification identifies multiple clients that are to receive the notification and that have the same distinguished server, and wherein the distinguished server is a server from which a client is to receive all notifications from the server pool.

7. The method of claim 6 wherein a load balancer assigns distinguished servers to clients.

8. A server pool of servers for sending notifications of presence information to subscribers of presence information of publishers, each server of the server pool for accessing presence-related information via a back-end database server, the back-end database server storing presence information of publishers and subscription information of subscribers, the publishers and subscribers being clients of presence information, comprising:

a load balancer that,

for each client,

receives for the server pool a logon request from the client; and

upon receiving the logon request from the client,

selects a server of the server pool to be assigned as being a distinguished server for the client based on number of clients assigned to each server; and

stores at the back-end database server an indication that the selected server has been assigned to be the distinguished server of the client;

receives an update to presence information of a publisher; and

after receiving the update,

determines the distinguished server of the publisher; and

sends to the distinguished server of the publisher an indication of the updated presence information of the publisher; and

a plurality of servers that

when a server is a distinguished server of a publisher,

receives from the load balancer an indication of updated presence information of the publisher;

stores at the back-end database server updated presence information of the publisher;

determines that an in-band notification is to be sent to subscribers to the presence information of the publisher by retrieving from the back-end database server an indication of subscribers to the presence information of the publisher;

identifies a distinguished server for each subscriber to the presence information of the publisher by retrieving from the back-end database server an indication of the distinguished server of each subscriber; and

sends an out-of-band notification to each distinguished server of each subscriber, the out-of-band notification indicating that the distinguished server is to send an in-band notification to the subscriber whose distinguished server is that distinguished server, the in-band notification indicating the updated presence information of the publisher so that the distinguished server of a subscriber can send to the subscriber a notification of the updated presence information; and

when the server is the distinguished server a subscriber of a publisher,

receives from the distinguished server of the publisher an out-of-band notification;

retrieves from the back-end database server, updated presence information of the publisher; and

sends the retrieved updated presence information to the subscriber.

9. The server pool of claim 8 wherein the in-band notification uses a session initiation protocol and the out-of-band notification uses a remote procedure call protocol.

10. The server pool of claim 8 wherein both the in-band and out-of-band notifications are encrypted.

11. The server pool of claim 8 wherein an out-of-band notification identifies multiple clients that are to receive an out-of-band notification and that have the same distinguished server.

12. One or more computer-readable storage media storing computer-executable instructions for controlling a server pool of servers to send notifications of presence information to subscribers of presence information of publishers, each server of the server pool for accessing presence-related information via a back-end database server, the back-end database server storing presence information of publishers and subscription information of subscribers, the publishers and subscribers being clients of presence information, by a method comprising:

for each client,

receiving at a load balancer for the server pool a logon request from the client; and

upon receiving the logon request from the client,

selecting at the load balancer a server of the server pool to be assigned as being a distinguished server for the client based on number of clients assigned to each server; and

storing by the load balancer at the back-end database server an indication that the selected server has been assigned to be the distinguished server of the client;

receiving at the load balancer an update to presence information of a publisher;

after receiving the update,

determining at the load balancer the distinguished server of the publisher; and

sending from the load balancer to the distinguished server of the publisher an indication of the updated presence information of the publisher;

storing at the back-end database server by the distinguished server of the publisher updated presence information of the publisher;

determining by the distinguished server of the publisher that an in-band notification is to be sent to subscribers to the presence information of the publisher by retrieving from the back-end database server an indication of subscribers to the presence information of the publisher;

identifying by the distinguished server of the publisher a distinguished server for each subscriber to the presence information of the publisher by retrieving from the back-end database server an indication of the distinguished server of each subscriber;

sending from the distinguished server of the publisher an out-of-band notification to each distinguished server of each subscriber, the out-of-band notification indicating that the distinguished server is to send an in-band notification to the subscriber whose distinguished server is that distinguished server, the in-band notification indicating the updated presence information of the publisher so that the distinguished server of a subscriber can send to the subscriber a notification of the updated presence information; and

under control of each distinguished server of each subscriber,

retrieving from the back-end database server, updated presence information of the publisher; and

sending the retrieved updated presence information to the subscriber.

13. The one or more computer-readable storage media of claim 12 wherein the in-band notification uses a session initiation protocol and the out-of-band notification uses a remote procedure call protocol.

14. The one or more computer-readable storage media of claim 12 wherein both the in-band and out-of-band notifications are encrypted.

15. The one or more computer-readable storage media of claim 12 wherein an out-of-band notification identifies multiple clients that are to receive an out-of-band notification and that have the same distinguished server.