Network traffic routing

• US 9,448,898 B2
• Filed: 07/11/2013
• Issued: 09/20/2016
• Est. Priority Date: 07/13/2004
• Status: Active Grant

• Current Assignee: Ongoing Operations LLC
• Original Assignee: Ongoing Operations LLC
• Inventors: Ocko, Matt, Tuma, George, Sukhija, Sandeep, Purrier, John, Gupta, Rajesh, Khajuria, Deepak, Das, Saumitra, Kalia, Manish
• Primary Examiner(s): DONAGHUE, LARRY D
• Application Number:
  US13/940,001
• Publication Number:
  US 20130305085A1
• Time in Patent Office: 1,167 Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/2023 Failover techniques
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 67/564 Enhancement of application control based on intercepted application data
• CPC Class Codes: H04L 67/59 Providing operational support to end devices by off-loading in the network or by emulation, e.g. when they are unavailable
• CPC Class Codes: H04L 67/63 Routing a service request depending on the request content or context
• 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

A service appliance is installed between production servers running service applications and service users. The production servers and their service applications provide services to the service users. In the event that a production server is unable to provide its service to users, the service appliance can transparently intervene to maintain service availability. To maintain transparency to service users and service applications, service users are located on a first network and production servers are located on a second network. The service appliance assumes the addresses of the service users on the second network and the addresses of the production servers on the first network. Thus, the service appliance obtains all network traffic sent between the production server and service users. While the service application is operating correctly, the service appliance forwards network traffic between the two networks using various network layers.

Claims

1. Apparatus comprising a storage medium storing a program for maintaining availability of a first service on a first server to plural client systems via a network, the instructions of the program for:

synchronizing a second service provided by a second server with the first service provided by the first server;

monitoring availability of the first service;

if the first service is unavailable, causing the second service to be substituted in place of the first service and monitoring a third service;

if the third service is available and capable of handling access by client systems, causing the third service to synchronize with the second service;

monitoring synchronization of the third service with the second service;

if the third service is synchronized with the second service, causing the third service to be substituted in place of the second service, such that the third service is responsive to communications from the client systems directed to the first service.

2. The apparatus of claim 1 further comprising the second server, the second server comprising the service appliance having a processor and a memory, wherein the processor and the memory comprise circuits and software for performing the instructions on the storage medium.

3. The method of claim 1, wherein the third service is provided by the first server following an interruption of the first service.

4. The apparatus of claim 1, the instructions of the program further for:

monitoring synchronization of the second service with the first service;

wherein monitoring availability of the first service comprises determining whether the first service is unresponsive to communications from client systems.

5. The apparatus of claim 1, wherein the instructions for causing the second service to be substituted in place of the first service further comprise instructions for:

receiving network traffic directed to the first server;

determining if the network traffic includes a service access;

if the network traffic includes the service access, causing the network traffic to be selectively provided to the second service, such that the second service responds to the service access.

6. The apparatus of claim 5, wherein the third service is provided by a third server, and wherein the instructions for synchronizing the third service with the second service further comprise instructions for:

(a) causing initiation of a first data transfer of service data from the second server to the third server at a first time, wherein the first data transfer comprises service data stored by the second server prior to the first time;

(b) upon completion of the first data transfer, causing initiation of an additional data transfer of service data from the second server to the third server at a subsequent time, wherein the second data transfer comprises service data created by the second server between the first time and the subsequent time;

(c) determining if the second server has created additional service data following a previous data transfer;

(d) in response to a determination that the second server has created additional service data following a previous data transfer, repeating (b), (c) and (d) for at least one additional data transfer.

7. The apparatus of claim 1, wherein the instructions for synchronizing the second service with the first service comprise instructions for:

determining a configuration of the first service;

configuring the second service to be compatible with the configuration;

replicating service data of the first service for the second service.

8. The apparatus of claim 7, wherein the instructions for replicating service data comprise instructions for:

(a) causing initiation of a first data transfer of the service data from the first server to the second server at a first time, the first data transfer comprising the service data created by the first server prior to the first time;

(b) upon completion of the first data transfer, causing initiation of an additional data transfer of the service data from the first server at a subsequent time, the second data transfer comprising the service data created by the first server between the first time and the subsequent time;

(c) repeating (b) a number of times.

9. The apparatus of claim 8, the instructions of the program further for:

(d) upon completion of (a), (b), and (c), initiating a wait state of the second server;

(e) during the wait state of the second server, causing initiation of a further data transfer of the service data from the first server to the second server following a time interval, wherein the further data transfers comprise the service data created by the first server during the time interval.

10. The apparatus of claim 8, the instructions of the program further for:

continually receiving network traffic directed to the first server;

caching at least a portion of the network traffic directed to the first server;

upon completion of (a), (b), and (c), initiating a wait state of the second server;

during the wait state of the second server, causing the cached network traffic to be provided to the second service.

11. The apparatus of claim 8 wherein the instructions for repeating (b) a number of times comprises instructions for detecting whether new service data is available and repeating (b) for the new service data.

12. The apparatus of claim 7 wherein the instructions for replicating service data comprise instructions for:

(a) causing initiation of a first data transfer of the service data from the first server to the second server at a first time, wherein the first data comprises the service data created by the first server prior to the first time;

(b) upon completion of the first data transfer, causing initiation of an additional data transfer of the service data from the first server at a subsequent time, wherein the second data comprises the service data created by the first server between the first time and the subsequent time;

(c) determining if the first server created additional service data following a previous data transfer;

(d) in response to a determination that the first server has created additional service data following a previous data transfer, repeating (b), (c) and (d) for at least one additional data transfer.

13. The apparatus of claim 12, the instructions of the program further for:

(e) upon completion of (a), (b), (c), and (d), initiating a wait state of the second server;

(f) during the wait state of the second server, causing initiation of a further data transfer of the service data from the first server to the second server following a time interval, wherein the further data transfers comprise the service data created by the first server during the time interval.

14. The apparatus of claim 12, the instructions of the program further for:

continually receiving network traffic directed to the first server;

caching at least a portion of the network traffic directed to the first server;

upon completion of (a), (b), and (c), initiating a wait state of the second server;

during the wait state of the second server, causing the cached network traffic to be provided to the second service.

15. The apparatus of claim 1, the instructions of the program further for causing the second server to enter a locked state which limits user administration of and operational control of the second server.

16. The apparatus of claim 15 wherein the locked state prevents running of additional applications other than those provided for prior to entering the locked state.

17. The apparatus of claim 1, the instructions of the program further for monitoring applications and components executing on the second server, and for terminating running applications and components if absent from a list of valid applications and components.

18. The apparatus of claim 1 the instructions of the program further for configuring the first data to be compatible with the second service data.

19. Apparatus comprising a storage medium storing a program for maintaining availability of a first service on a first server, the instructions of the program for:

synchronizing a second service provided by a second server with the first service provided by the first server;

monitoring at least one of the first server and availability of the first service;

if monitoring indicates that the first server is in a failure condition or the first service is unavailable, causing the second service to be substituted in place of the first service.

20. The apparatus of claim 19 further comprising the second server, the second server comprising a service appliance having a processor and a memory, wherein the processor and the memory comprise circuits and software for performing the instructions on the storage medium.

21. The apparatus of claim 19, the instructions of the program further for:

monitoring synchronization of the second service with the first service;

wherein monitoring availability of the first service comprises determining whether the first service is unresponsive to communications from the client systems.

22. The apparatus of claim 19, wherein the instructions for causing the second service to be substituted in place of the first service further comprise instructions for:

receiving network traffic directed to the first server;

determining if the network traffic includes a service access;

if the network traffic includes the service access, causing the network traffic to be selectively provided to the second service, such that the second service responds to the service access.

23. The apparatus of claim 19 wherein the instructions for synchronizing the second service with the first service comprise instructions for:

determining a configuration of the first service;

configuring the second service to be compatible with the configuration;

replicating service data of the first service.

24. The apparatus of claim 23 wherein the instructions for replicating service data comprise instructions for:

(a) causing initiation of a first data transfer of the service data from the first server to the second server at a first time, the first data transfer comprising the service data created by the first server prior to the first time;

(b) upon completion of the first data transfer, causing initiation of an additional data transfer of the service data from the first server at a subsequent time, the second data transfer comprising the service data created by the first server between the first time and the subsequent time;

(c) repeating (b) a number of times.

25. The apparatus of claim 24, the instructions of the program further for:

(d) upon completion of (a), (b), and (c), initiating a wait state of the second server;

(e) during the wait state of the second server, causing initiation of a further data transfer of the service data from the first server to the second server following a time interval, wherein the further data transfers comprise the service data created by the first server during the time interval.

26. The apparatus of claim 24 wherein the instructions for repeating (b) a number of times comprises instructions for detecting whether new service data is available and repeating (b) for the new service data.

27. The apparatus of claim 24, the instructions of the program further for:

continually receiving network traffic directed to the first server;

caching at least a portion of the network traffic directed to the first server; and

upon completion of (a), (b), and (c), initiating a wait state of the second server;

during the wait state of the second server, causing the cached network traffic to be provided to the second service.

28. The apparatus of claim 23 wherein the instructions for replicating service data comprise instructions for:

(a) causing initiation of a first data transfer of the service data from the first server to the second server at a first time, wherein the first data comprises the service data created by the first server prior to the first time;

(b) upon completion of the first data transfer, causing initiation of an additional data transfer of the service data from the first server at a subsequent time, wherein the second data comprises the service data created by the first server between the first time and the subsequent time;

(c) determining if the first server created additional service data following a previous data transfer;

(d) in response to a determination that the first server has created additional service data following a previous data transfer, repeating (b), (c) and (d) for at least one additional data transfer.

29. The apparatus of claim 28, the instructions of the program further for:

(e) upon completion of (a), (b), (c), and (d), initiating a wait state of the second server;

(f) during the wait state of the second server, causing initiation of a further data transfer of the service data from the first server to the second server following a time interval, wherein the further data transfers comprise the service data created by the first server during the time interval.

30. The apparatus of claim 28, the instructions of the program further for:

continually receiving network traffic directed to the first server;

caching at least a portion of the network traffic directed to the first server;

upon completion of (a), (b), and (c), initiating a wait state of the second server;

during the wait state of the second server, causing the cached network traffic to be provided to the second service;

during the wait state of the second server, causing at least a portion of the cached network traffic to be provided to the first server to enable the first service to respond to the network traffic.

31. The apparatus of claim 19, the instructions of the program further for, after causing the second service to be substituted in place of the first service:

monitoring at least one of the first server and availability of the first service;

if monitoring indicates that the first server is available in an operational condition or the first service is available, causing the first service of the first server to be synchronized with the second service of the second server;

after completion of synchronization of the first service with the second service, causing the first service to be substituted in place of the second service.

32. The apparatus of claim 19 wherein the instructions for causing the second service to be substituted in place of the first service further comprise instructions for:

receiving network traffic directed to the first server;

determining if the received network traffic includes a service access;

if the network traffic includes the service access, providing the network traffic to the second service, such that the second service responds to the service access.

33. The apparatus of claim 32 wherein the instructions for causing the second service to be substituted in place of the first service further comprise instructions for, if the network traffic includes the service access, blocking at least a portion of the network traffic from the first server.

34. Apparatus comprising a storage medium storing a program for maintaining availability of a first service on a first server;

the instructions of the program for moving a second server between states comprising;

an initialization state, wherein following the installation of the second server, the second server is configured and automatically replicates e-mail, calendaring and relevant configuration information from the first server onto itself;

a transparent wait state, wherein the second server passively stays in sync with the first server and is ready to take over servicing of e-mail and calendaring requests in case the first server fails;

a failover state, wherein the second server detects the first server failure and takes over the servicing of e-mail and calendaring requests from systems and users connected to the first server;

a prepare to failback state, wherein the second server determines that the first server is capable of providing the first service, and the second server auto-replicates the e-mail and calendar data back to the first server so that the first server can get e-mails received and handled by the second server while the first server was down;

a failback state, wherein the second server has completed replication of e-mail and calendaring data to the first server, and the second server hands over servicing e-mail and calendaring requests back to the first server.

35. The apparatus of claim 34 wherein replication includes data from databases internal and external to the first server.

36. The apparatus of claim 34 wherein the failback state comprises the second server returning control of the first service to the first server for specific users as associated service data becomes synchronized on the second server and the first server, while the second server continues to control the first service for users with unsynchronized data.

37. The apparatus of claim 34 wherein the program comprises a service application executed in one or more virtual machines running on one or more CPUs of the second server.