Failure detection and reporting for a computer mail gateway

• US 5,644,706 A
• Filed: 04/30/1996
• Issued: 07/01/1997
• Est. Priority Date: 06/20/1994
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Ross, James, Ruigrok, Adrian, Alikashani, Safa, Wallace, Andrew John, Laforce, Marcel, Koorland, Neil Karl, Kratz, Geoffrey G.
• Primary Examiner(s): Beusoliel, Jr., Robert W.
• Assistant Examiner(s): LE, DIEU MINH T
• Application Number:
  US08/641,412
• Time in Patent Office: 427 Days
• Field of Search: 395/185.01, 395/183.07, 395/183.15, 395/183.22, 371/8.2, 371/11.2, 371/20.1, 371/34, 371/35, 364/241.7, 370/28, 370/32, 370/85.13
• US Class Current: 714/48
• CPC Class Codes: G06F 11/0757 by exceeding a time limit, i.e. time-out, e.g. watchdogs
• CPC Class Codes: H04L 41/06 Management of faults, events, alarms or notifications
• CPC Class Codes: H04L 41/0896 Bandwidth or capacity management, i.e. automatically increasing or decreasing capacities flow or congestion control using dynamic resource allocation, e.g. in-call renegotiation, H04L47/76
• 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 51/234 for tracking messages
• 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

Failure detection and reporting for a computer mail gateway is provided. In a preferred embodiment, two computer mail systems are connected by a gateway. The gateway includes an automatic gateway failure detection and reporting facility. The gateway also includes a message transfer store. The facility transmits a message from the first mail system into the message transfer store for retrieval by the second mail system. The facility then detects that the transmitted message from the first mail system has remained in the message transfer store for at least a predetermined time without being retrieved by the second mail system. In response to detecting that the transmitted message from the first mail system has remained in the message transfer store for at least a predetermined time without being retrieved by the second mail system, the facility diagnoses the failure of the gateway. In a further preferred embodiment, after diagnosing the failure of the gateway, the facility provides an indication that the gateway has failed to a user of the first mail system that can remediate the gateway failure. In a further preferred embodiment, the facility transmits test messages into the message transfer store to assist in detecting the failure of the gateway when no normal message traffic is traveling through the gateway.

Claims

1. A method in a computer mail gateway for diagnosing the failure of the gateway, the gateway being for forwarding messages from a first mail system to a second mail system via a message transfer store, the gateway comprising the message transfer store, a first gateway component for transferring messages from the first mail system to the message transfer store, and a second gateway component for retrieving messages from the message transfer store for forwarding to the second mail system, the method comprising the steps of:

transmitting a dummy message from the first gateway component to the message transfer store, said dummy message being transmitted to decide whether the second gateway component has failed;

under the control of the first gateway component, detecting that the dummy message from the first gateway component has remained in the message transfer store for at least a predetermined time; and

in response to the detecting step, determining that the gateway has failed.

2. The method of claim 3, further including the step of, in response to the determining step and under the control of the first gateway component, transmitting a diagnostic message to a computer mail user of the:

first computer mail system indicating the failure of the gateway.

a diagnosis subsystem for diagnosing the failure of the connected

3. The method of claim 1 wherein the detecting step includes the steps of:

initiating transmission of a second message from the first gateway component to the message transfer store; and

detecting that the initiated transmission of the second message was not completed, whereby the failure of the second gateway component is diagnosed.

4. The method of claim 3 wherein the second message is a dummy message transmitted into the gateway for the purpose of determining whether the second gateway component has failed.

5. The method of claim 4, further including the step of periodically transmitting dummy messages into the gateway for the purpose of determining whether the second gateway component has failed.

6. The method of claim 4, wherein the gateway being for forwarding primary messages and dummy messages, further including the step of transmitting dummy messages into the gateway when no primary messages are being transmitted into the gateway for the purpose of determining whether the second gateway component has failed.

7. In a compound computer mail system comprised of a first mail system, a second mail system, and a gateway for passing messages between the first mail system and the second mail system, the gateway including a message transfer store for storing messages, the second mail system including a retrieval gateway component for retrieving messages from the message transfer store, a method for testing a status of the gateway, comprising the steps of:

transmitting a test message addressed to the second mail system, where the test message is stored in the message transfer store until the retrieval gateway component retrieves the test message;

after a predetermined period of time has expired, determining whether the test message remains stored in the message transfer store;

when it is determined that the test message has not remained stored in the message transfer store, generating an indication at the gateway that the gateway is operating properly; and

when it is determined that the test message has remained stored in the message store, generating an indication at the gateway that the gateway is not operating properly.

8. The method of claim 7, further including the steps of, when it is determined that the test message has not remained stored in the message transfer store, determining that the test message was received in the second mail system and discarding the test message without delivering the test message to a computer mail user.

9. The method of claim 7, further including the steps of, when it determined that the test message has not remained stored in the message transfer store, determining that the test message was not received in the second mail system and providing at the gateway to a user of the first mail system an indication that the gateway is not operating properly.

10. A method in a compound computer mail system comprised of a first mail system, a second mail system, and a gateway connecting the first mail system and the second mail system, the method for using testing messages to detect a failure of the gateway and comprising the steps of:

transmitting a test message addressed to the second mail system; and

detecting the failure of the gateway based on whether the test message remains at the gateway for longer than a predetermined period of time.

11. A computer mail system for diagnosing the failure of a connected computer mail system, the connected computer mail system processing messages transmitted to it by the computer mail system when the connected computer mail system has not failed, comprising:

a message transmission subsystem for transmitting a message to the connected computer mail system,

a message storage for storing the message transmitted by the message transmission subsystem until retrieved by the connected computer mail system;

a message processing timer for determining a period of time during which the message remains stored in the message storage;

a diagnosis subsystem for diagnosing the failure of the connected computer mail system when the message processing timer indicates that the message remained stored in the message storage for a predetermined period of time; and

a dummy interval memory for storing a time interval at which the scheduler periodically causes the message transmission subsystem to transmit dummy messages to the connected mail system.

12. The computer mail system of claim 11, further including a scheduler for causing the message transmission subsystem to periodically transmit dummy messages to the connected mail system.

13. The computer mail system of claim 11, further including a failure reporting subsystem for causing the message transmission subsystem to transmit a message to a user of the mail system indicating that the connected computer mail system has failed if the diagnosis subsystem diagnoses the failure of the connected computer mail system.

14. A computer mail gateway for passing messages between a first mail system and a second mail system and capable of diagnosing its own failure, comprising:

a message transfer store for storing messages being passed between the first mail systems and the second mail system;

a gateway component for causing messages sent from the first mail system to the second mail system, to be stored in the message transfer store and causing messages sent from the second mail system to the first mail system to be retrieved from the message transfer store; and

a failure diagnosis subsystem for determining whether the gateway has failed, comprising;

a monitoring stage for monitoring a length of time each message remains in the message transfer store;

a dummy message generator for generating dummy messages that are transmitted to the message transfer store to determine whether the gateway has failed;

a verification stage for verifying whether each message remains in the message transfer store for more than a predetermined period of time; and

a result stage for generating an indication that the gateway has failed when the monitoring stage indicates a message remained in the message transfer store for longer than a predetermined period of time, whereby the failure diagnosis subsystem determines the gateway has failed.

15. The computer mail gateway of claim 14, further including a failure reporting subsystem for receiving an indication that the gateway has failed from the failure diagnosis subsystem and transmitting a message indicating that the gateway has failed to a user of one of the mail systems.

16. A computer-readable medium holding instructions for performing a method in a computer mail gateway for diagnosing the failure of the gateway, the gateway being for forwarding messages from a first mail system to a second mail system via a message transfer store, the gateway comprising the message transfer store, a first gateway component for transferring messages from the first mail system to the message transfer store, and a second gateway component for retrieving messages from the message transfer store for forwarding to the second mail system, the method comprising the steps of:

transmitting a dummy message from the first gateway component to the message transfer store, said dummy message being transmitted to decide whether the second gateway component has failed;

under the control of the first gateway component, detecting that the dummy message from the first gateway component has remained in the message transfer store for at least a predetermined time; and

in response to the detecting step, determining that the gateway has failed.

17. The computer-readable medium of claim 16 wherein the method further comprises the step of, in response to the diagnosing step and under the control of the first gateway component, transmitting a diagnostic message to a computer mail user of the first computer mail system indicating the failure of the gateway.

18. The computer-readable medium of claim 16 wherein the detecting step includes the steps of:

initiating transmission of a second message from the first gateway component to the message transfer store; and

detecting that the initiated transmission of the second message was not completed, whereby the failure of the second gateway component is diagnosed.

19. The computer-readable medium of claim 18 wherein the second message is a dummy message transmitted into the gateway for the purpose of determining whether the second gateway component has failed.

20. The computer-readable medium of claim 19 wherein the method further comprises the step of periodically transmitting dummy messages into the gateway for the purpose of determining whether the second gateway component has failed.

21. The computer-readable medium of claim 20 wherein the gateway being for forwarding primary messages and dummy messages, further including the step of transmitting dummy messages into the gateway when no primary messages are being transmitted into the gateway for the purpose of determining whether the second gateway component has failed.

22. In a compound computer mail system comprised of a first mail system, a second mail system, and a gateway for passing messages between the first mail system and the second mail system, the gateway including a message transfer store for storing messages, the second mail system including a retrieval gateway component for retrieving messages from the message transfer store, a computer-readable medium holding instructions for performing a method for testing a status of the gateway, comprising the steps of:

transmitting a test message addressed to the second mail system, where the test message is stored in the message transfer store until the retrieval gateway component retrieves the test message;

after a predetermined period of time has expired, determining whether the test message remains stored in the message transfer store;

when it is determined that the test message has not remained stored in the message transfer store, generating an indication at the gateway that the gateway is operating properly; and

when it is determined that the test message has remained stored in the message store, generating an indication at the gateway that the gateway is not operating properly.

23. The computer-readable medium of claim 22 wherein the method further comprises the steps of, when it is determined that the test message has not remained stored in the message transfer store, determining that the test message was received in the second mail system and discarding the test message without delivering the test message to a computer mail user.

24. The computer-readable medium of claim 22 wherein the method further comprises the steps of, when it determined that the test message has not remained stored in the message transfer store, determining that the test message was not received in the second mail system and providing at the gateway to a user of the first mail system an indication that the gateway is not operating properly.

25. A computer-readable medium holding instructions for performing a method in a compound computer mail system comprised of a first mail system, a second mail system, and a gateway connecting the first mail system and the second mail system, the method for using testing messages to detect a failure of the gateway and comprising the steps of:

transmitting a test message addressed to the second mail system; and

detecting the failure of the gateway based on whether the test message remains at the gateway for longer than a predetermined period of time.