Method and system for servicing requests in a dynamic cluster

• US 20070124380A1
• Filed: 11/22/2006
• Published: 05/31/2007
• Est. Priority Date: 11/23/2005
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Carr, Harold, Cavanaugh, Ken
• Granted Patent: US 7,743,167 B2
• Time in Patent Office: Days
• US Class Current: 709/204
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/61 taking into account QoS or priority requirements
• CPC Class Codes: H04L 67/63 Routing a service request depending on the request content or context

Abstract

A method for servicing requests in a dynamic cluster that includes receiving, by a first replica of the dynamic cluster, a first request that includes a first membership label from a client, wherein the client stores the first membership label and a first cluster list, determining whether the first membership label is obsolete, and sending a second membership label and a second cluster list to the client when the first membership label is obsolete, wherein the client updates the first cluster list with the second cluster list.

Claims

1. A method for servicing requests in a dynamic cluster comprising:

receiving, by a first replica of the dynamic cluster, a first request comprising a first membership label from a client,

wherein the client stores the first membership label and a first cluster list;

determining whether the first membership label is obsolete; and

sending a second membership label and a second cluster list to the client when the first membership label is obsolete,

wherein the client updates the first cluster list with the second cluster list.

2. The method of claim 1, further comprising:

receiving a second request comprising the second membership label from the client,

wherein receiving the second membership label and the second request is performed by a second replica of the dynamic cluster, and

wherein the second replica is in the second cluster list; and

sending a response based on the second request to the client.

3. The method of claim 1, wherein a header of the first request comprises an object key and a service context, and wherein the service context comprises the first membership label.

4. The method of claim 1, wherein determining whether the first membership label is obsolete comprises:

intercepting the first request by an interceptor executing on the first replica; and

comparing the first membership label with a stored membership label.

5. The method of claim 1, wherein the sending the second membership label and the cluster list comprises:

intercepting a response based on the first request to the client;

adding an updated object reference to the response, wherein the updated object reference comprises the second membership label and the second cluster list; and

sending the response to the client.

6. The method of claim 5, wherein the first request comprises an object key and the object key comprises an obsolete object reference, and the method further comprises:

identifying a reference factory from the object key;

obtaining an object reference template from the reference factory; and

updating the obsolete object reference using the object reference template to create the updated object reference.

7. The method of claim 6, wherein the object reference template comprises the second membership label and the second cluster list.

8. The method of claim 1, further comprising:

receiving notification of a cluster list change; and

updating a reference factory to create an updated reference factory, wherein the updated reference factory comprises an object reference template with the second membership label and the second cluster list.

9. The method of claim 8, further comprising:

destroying an obsolete object adaptor maintained by the reference factory in response to the notification;

creating a new object adaptor by the updated reference factory when the first request is received; and

creating an object reference using the new object adaptor.

10. The method of claim 9, wherein creating a new object adaptor is performed using an adaptor activator.

11. The method of claim 1, further comprising:

receiving a notification of a cluster list change;

generating the second membership label by the first replica in response to the notification; and

generating a third membership label by a second replica in response to the notification,

wherein the second membership label and the third membership label are distinct.

12. The method of claim 2, wherein the second replica is chosen to receive the second request based on a priority in the second cluster list.

13. The method of claim 1, further comprising:

storing a last replica identifier by the client, wherein requests are transmitted only to a last replica identified by the last replica identifier until the last replica fails.

14. A system comprising:

a first replica that;

receives a first request comprising a first membership label from a client,

determines whether the first membership label is obsolete; and

sends a second membership label and a cluster list to the client when the first membership label is obsolete,

wherein the client updates a client cluster list with the cluster list; and

a second replica that;

receives a second request comprising the second membership label from the client; and

sends a response based on the second request to the client, wherein the second replica is in the cluster list.

15. The system of claim 14, wherein a header of the first request comprises an object key and a service context, and wherein the service context comprises the first membership label.

16. The system of claim 15, further comprising:

a server group manager configured to execute on the first replica,

wherein the server group manager determines whether the first membership label is obsolete, wherein determining whether the first membership label is obsolete comprises;

intercepting the first request by an interceptor executing on the first replica;

accessing the service context of the first request by the interceptor; and

comparing the first membership label with a stored membership label.

17. The system of claim 14, further comprising:

a server group manager configured to execute on the first replica,

wherein the server group manager sends the second membership label and the cluster list, wherein sending the second membership label and the cluster list comprises;

intercepting a response to the client based on the first request;

adding an updated object reference to the response, wherein the updated object reference comprises the second membership label and the cluster list; and

sending the response to the client.

18. The system of claim 17, wherein the server group manager further:

identifies a reference factory from an object key, wherein the first request comprises the object key and the object key comprises an obsolete object reference; and

creates the updated object reference using an object reference template, wherein the object reference template is obtained from the reference factory.

19. The system of claim 14, wherein the client stores a last replica identifier, and wherein requests are transmitted only to a last replica identified by the last replica identifier until the last replica fails.

20. A computer usable medium comprising computer readable program code embodied therein for causing a replica in a dynamic cluster to:

receive a request comprising a first membership label from a client, wherein the client stores the first membership label and a first cluster list;

determine whether the first membership label is obsolete; and

send a second membership label and a second cluster list to the client when the first membership label is obsolete,

wherein the client updates the first cluster list with the second cluster list.