Independent message stores and message transport agents

• US 20070106783A1
• Filed: 11/07/2005
• Published: 05/10/2007
• Est. Priority Date: 11/07/2005
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Warman, Leon, Pearson, Malcolm, Curtis, Loren, McMillan, Bruce
• Granted Patent: US 8,077,699 B2
• Time in Patent Office: Days
• US Class Current: 709/224
• CPC Class Codes: H04L 51/00 User-to-user messaging in packet-switching networks, transmitted according to store-and-forward or real-time protocols, e.g. e-mail
• CPC Class Codes: H04L 51/23 Reliability checks, e.g. acknowledgments or fault reporting
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

Multiple independent MTAs transmit messages such that if one of the MTAs fails, the other MTAs may continue to transmit messages. Multiple independent message stores are provided such that if one of the message stores fails, messages on the other message stores may continue to be transmitted. Multiple notification agents monitor the message stores for new messages and notify one of the MTAs when a new message is available for transmission.

Claims

1. A computerized method, comprising:

monitoring a message store for new messages;

obtaining a list of a plurality of message transport agents (MTA), wherein each MTA has access to the monitored message store;

selecting one of the plurality of MTAs when a new message is received by the monitored message store; and

notifying the selected MTA that the received new message is available for transmission, so that the selected MTA responds to the notification by transmitting the received new message to a specified destination.

2. The method of claim 1, further comprising monitoring additional message stores for new messages, obtaining a list of the monitored message stores, and wherein the selecting includes selecting as a function of the list of MTAs and the list of monitored message stores one of the plurality of MTAs when a new message is received by one of the monitored message stores.

3. The method of claim 1, wherein the MTA is selected to balance the load of the selected MTA with respect to the load of other MTAs in the list of MTAs.

4. The method of claim 1, wherein the MTA is selected from the list of MTAs using a round-robin algorithm.

5. The method of claim 1, wherein the MTA is selected as a function of at least one of the following:

a load capacity of each of the plurality of MTAs; and

a current load of each of the plurality of MTAs.

6. The method of claim 1, wherein the selecting of the MTA further comprises checking an override list containing a subset of the plurality of MTAs, and selecting the MTA from the override list.

7. The method of claim 1, wherein the notifying includes providing at least one of the following parameters associated with the received new message to the selected MTA:

an entry identifier, a parent entry identifier, a message class, and a mailbox identifier.

8. The method of claim 1 further comprises:

receiving a return value from the selected MTA, wherein the return value indicates that the transmission of the received message by the selected MTA was successful.

9. The method of claim 1 further comprises:

receiving a return value from the selected MTA, wherein the return value indicates if the transmission of the received message by the selected MTA was unsuccessful;

modifying the list of MTAs by removing the selected MTA from the list of MTAs;

selecting a new MTA from the modified list of MTAs; and

notifying the new MTA that the received message is available for transmission, so that the new MTA responds to the notification by transmitting the received message to a specified destination.

10. The method of claim 1, wherein if one of the plurality of MTAs is inaccessible, the inaccessible MTA is removed from the list of MTAs.

11. The method of claim 10, wherein the removed inaccessible MTA is added back to the list of MTAs after a period of time.

12. The method of claim 1, wherein if the list of MTAs is empty, further comprising:

writing an event log entry, wherein the entry indicates that no MTA can be found to transmit the new received message.

13. The method of claim 1 further comprising:

tracking of performance counters, wherein said counters are related to the notifying of the selected MTA and include at least one of the following;

remote calls per second, remote calls, and number of inaccessible MTAs.

14. The method of claim 1, wherein one or more computer-readable media have computer-executable instructions for performing the method of claim 1.

15. A system, comprising:

a plurality of message stores;

a plurality of notification agents, each associated with one of the plurality of message stores, wherein each notification agent monitors its associated message store for new messages;

a plurality of MTAs, each of which is accessible by each of the notification agents, wherein each MTA can access each of the message stores;

wherein the notification agent selects one of the plurality of MTAs when a new message is received, and said notification agent notifies the selected MTA that the received message is available for transmission;

wherein the selected MTA responds to the notification by transmitting the received message to a specified destination.

16. The system of claim 15, wherein the plurality of MTAs and the plurality of notification agents are within a cluster the cluster further comprises:

a first server, executing the selected MTA; and

a second server, independent of the first server, executing the notification agent.

17. The system of claim 15, wherein the MTA is selected to balance the load of the selected MTA with respect to other MTAs of the list of MTAs.

18. The system of claim 15, wherein the MTA is selected from the list of MTAs using a round-robin algorithm.

19. The system of claim 15, wherein the MTA is selected as a function of at least one of the following:

the load capacity of each of the plurality of MTAs; and

a current load of each of the plurality of MTAs.

20. In a system wherein new messages are stored in a single message store for transmission by a single MTA, the improvement comprising:

additional message stores;

additional MTAs, wherein each MTA can access each message store;

a plurality of notification agents, each associated with a message store, wherein each notification agent monitors the associated message store for new messages;

wherein the notification agent selects one of the plurality of MTAs when a new message is received, and said notification agent notifies the selected MTA that the received message is available for transmission;

wherein the MTA responds to the notification by transmitting the received message to a specified destination; and

whereby if a message store is inaccessible and a remaining message store is accessible, the received messages on the remaining accessible message store may be transmitted, thus minimizing the impact of the inaccessible message store as a single point of failure; and

if the selected MTA is inaccessible and a remaining MTA is accessible, the received message may be transmitted by the remaining accessible MTA, thus eliminating the selected MTA as a single point of failure.