System and method for enabling site failover in an application server environment

• US 20070174660A1
• Filed: 04/03/2006
• Published: 07/26/2007
• Est. Priority Date: 11/29/2005
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: BEA Systems Incorporated (Oracle Corporation)
• Inventors: Peddada, Prasad
• Granted Patent: US 7,702,947 B2
• Time in Patent Office: Days
• US Class Current: 714/4
• CPC Class Codes: H04L 41/0663 Performing the actions predefined by failover planning, e.g. switching to standby network elements
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1027 Persistence of sessions during load balancing
• CPC Class Codes: H04L 67/1034 Reaction to server failures by a load balancer
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• 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
• CPC Class Codes: Y04S 40/00 Systems for electrical power generation, transmission, distribution or end-user application management characterised by the use of communication or information technologies, or communication or information technology specific aspects supporting them

Abstract

A system and method for enabling site failover in an application server or clustered environment. In addition to providing HTTP session state replication across servers within a cluster, the invention provides the ability to replicate HTTP session state across multiple clusters. This improves high-availability and fault tolerance by allowing clusters to be spread across multiple geographic regions, power grids, and Internet service providers.

Claims

1. A system for enabling site failover in an application server or clustered environment, comprising:

a first cluster, including a first plurality of servers executing therein that processes requests, and having a first local load balancer associated therewith;

a second cluster, including a second plurality of servers executing therein that processes requests, and having a second local load balancer associated therewith; and

wherein a primary server selected from the first plurality of servers in the first cluster replicates http session information to a secondary server selected from the second plurality of servers in the second cluster, via a replication channel between the first cluster and the second cluster, for use in enabling site failover between the plurality of clusters.

2. The system of claim 1, further comprising a global load balancer for distributing http session requests to a plurality of clusters, said plurality of clusters comprising the first cluster and the second cluster.

3. The system of claim 1, wherein the system is configured for use in a metropolitan area network (MAN), and wherein the plurality of clusters are distributed on a MAN.

4. The system of claim 3, wherein the replication channel includes an in-memory replication that operates between the first cluster and the second cluster, and allows session state to be replicated synchronously from the first cluster to the second cluster.

5. The system of claim 3, wherein, once a request reaches a particular one of the servers in either the first cluster or the second cluster, the particular server becomes the primary server for that HTTP session, and the particular server handles subsequent requests assuming there are no failures, and wherein, after the server establishes the HTTP session, the current session state is replicated to a designated secondary server in another cluster.

6. The system of claim 3, wherein, once a client establishes a connection to a cluster, then the client maintains stickiness to that cluster, using information stored in a cookie at the client.

7. The system of claim 1, wherein the system is configured for use in a wide area network (WAN), and wherein the plurality of clusters are distributed on a WAN.

8. The system of claim 7, wherein each of the plurality of clusters has a database associated therewith, that includes HTTP session information stored therein, which the replication channel then uses to provide failover across the plurality of clusters using asynchronous data replication.

9. The system of claim 7, wherein during WAN replication, once the request a particular one of the servers in either the first cluster or the second cluster, the particular server becomes the primary server for that HTTP session, and the particular server handles subsequent requests assuming there are no failures, and wherein, after the server establishes the HTTP session, the current session state is replicated to a designated secondary server.

10. The system of claim 7, wherein the asynchronous data replication uses in-memory replication within a first cluster and periodically makes a remote request to the second cluster to persist the session state to the database at the second cluster.

11. A method enabling site failover in an application server or clustered environment, comprising the steps of:

providing a first cluster, including a first plurality of servers executing therein for processing requests, and having a first local load balancer associated therewith;

providing a second cluster, including a second plurality of servers executing therein for processing requests, and having a second local load balancer associated therewith; and

replicating information across the clusters, wherein a primary server selected from the first plurality of servers in the first cluster replicates http session information to a secondary server selected from the second plurality of servers in the second cluster, via a replication channel between the first cluster and the second cluster, for use in enabling site failover between the plurality of clusters.

12. The method of claim 11, further comprising receiving http session requests by a global load balancer for distributing of the requests to a plurality of clusters, said plurality of clusters comprising the first cluster and the second cluster.

13. The method of claim 11, wherein the system is configured for use in a metropolitan area network (MAN), and wherein the plurality of clusters are distributed on a MAN.

14. The method of claim 13, wherein the replication channel includes an in-memory replication that operates between the first cluster and the second cluster, and allows session state to be replicated synchronously from the first cluster to the second cluster.

15. The method of claim 13, wherein, once a request reaches a particular one of the servers in either the first cluster or the second cluster, the particular server becomes the primary server for that HTTP session, and the particular server handles subsequent requests assuming there are no failures, and wherein, after the server establishes the HTTP session, the current session state is replicated to a designated secondary server in another cluster.

16. The method of claim 13, wherein, once a client establishes a connection to a cluster, then the client maintains stickiness to that cluster, using information stored in a cookie at the client.

17. The method of claim 11, wherein the system is configured for use in a wide area network (WAN), and wherein the plurality of clusters are distributed on a WAN.

18. The method of claim 17, wherein each of the plurality of clusters has a database associated therewith, that includes HTTP session information stored therein, which the replication channel then uses to provide failover across the plurality of clusters using asynchronous data replication.

19. The method of claim 17, wherein during WAN replication, once the request a particular one of the servers in either the first cluster or the second cluster, the particular server becomes the primary server for that HTTP session, and the particular server handles subsequent requests assuming there are no failures, and wherein, after the server establishes the HTTP session, the current session state is replicated to a designated secondary server.

20. The method of claim 17, wherein the asynchronous data replication uses in-memory replication within a first cluster and periodically makes a remote request to the second cluster to persist the session state to the database at the second cluster.