Dynamic lookup service in a distributed system

• US 8,713,089 B2
• Filed: 04/08/2003
• Issued: 04/29/2014
• Est. Priority Date: 02/26/1998
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Oracle America, Inc. (Oracle Corporation)
• Inventors: Murphy, Brian T., Scheifler, Robert W., Pan, Zane, Waldo, James H., Wollrath, Ann M., Arnold, Kenneth C. R. C.
• Primary Examiner(s): Blair, Douglas
• Assistant Examiner(s): AILES, BENJAMIN A
• Application Number:
  US10/408,365
• Publication Number:
  US 20030191842A1
• Time in Patent Office: 4,039 Days
• Field of Search: 709/203, 709/224, 709/250, 707/1
• US Class Current: 709/203
• CPC Class Codes: G06F 12/0261 using reference counting
• CPC Class Codes: G06F 16/289 Object oriented databases
• CPC Class Codes: G06F 21/54 by adding security routines or objects to programs
• CPC Class Codes: G06F 2209/462 Lookup
• CPC Class Codes: G06F 2209/5015 Service provider selection
• CPC Class Codes: G06F 9/465 Distributed object oriented systems remote method invocation [RMI] G06F9/548
• CPC Class Codes: G06F 9/505 considering the load
• CPC Class Codes: G06F 9/5055 considering software capabilities, i.e. software resources associated or available to the machine
• CPC Class Codes: G06F 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores
• CPC Class Codes: G06F 9/542 Event management; Broadcasting; Multicasting; Notifications
• CPC Class Codes: G06F 9/547 Remote procedure calls [RPC]; Web services
• CPC Class Codes: G06F 9/548 Object oriented; Remote method invocation [RMI] non-remote method invocation G06F9/449
• CPC Class Codes: H04L 12/2803 Home automation networks
• CPC Class Codes: H04L 12/2805 Home Audio Video Interoperability [HAVI] networks
• CPC Class Codes: H04L 12/2807 Exchanging configuration information on appliance services in a home automation network arrangements for maintenance or administration involving network analysis for automatically determining the actual topology of a network H04L41/12; hardware or software tools for network management using graphical user interfaces H04L41/22; address allocation H04L61/50
• CPC Class Codes: H04L 12/2809 indicating that an appliance service is present in a home automation network monitoring functionality H04L43/0817; discovery or management thereof, e.g. service location protocol [SLP] or web services, H04L67/51
• CPC Class Codes: H04L 12/40032 Details regarding a bus interface enhancer
• CPC Class Codes: H04L 12/40169 Flexible bus arrangements arrangements for maintenance or administration involving management of faults; events, alarms H04L41/06; automatic restoration of network faults H04L41/0654
• CPC Class Codes: H04L 12/403 with centralised control, e.g. polling
• CPC Class Codes: H04L 12/417 with deterministic access, e.g. token passing
• CPC Class Codes: H04L 67/01 : Protocols
• CPC Class Codes: H04L 67/10 : in which an application is distributed across nodes in the network software deployment G06F8/60; multiprogramming arrangements G06F9/46
• CPC Class Codes: H04L 67/133 : Protocols for remote procedure calls [RPC]
• CPC Class Codes: H04L 67/51 : Discovery or management thereof, e.g. service location protocol [SLP] or web services
• CPC Class Codes: H04L 67/55 : Push-based network services
• CPC Class Codes: H04L 67/561 : Adding application-functional data or data for application control, e.g. adding metadata
• CPC Class Codes: H04L 67/568 : Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: H04L 69/24 : Negotiation of communication capabilities
• CPC Class Codes: H04L 69/329 : in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 : Network security protocols

Abstract

An improved lookup service is provided that allows for the dynamic addition and deletion of services. This lookup service allows for the addition and deletion of services automatically, without user intervention. As a result, clients of the lookup service may continue using the lookup service and its associated services while the updates occur. Additionally, the lookup service provides a notification mechanism that can be used by clients to receive a notification when the lookup service is updated. By receiving such a notification, clients can avoid attempting to access a service that is no longer available and can make use of new services as soon as they are added to the lookup service.

Claims

1. A method in a distributed system having a lookup service with associated network services and a client lookup manager with an associated cache, the method comprising the steps of:

transmitting a request for discovery of at least one lookup service by the client lookup manager;

receiving said request by a discovery server;

transmitting an object, responsive to the request, to the client lookup manager, wherein the object provides a reference to at least one lookup service;

receiving said object by the client lookup manager;

using the reference to register a callback routine with the at least one lookup service by the client lookup manager;

observing, by the at least one lookup service, a change to one of the associated network services;

determining that the callback routine has been registered with the lookup service;

transmitting, based on the observing and determining, an event by the at least one lookup service that identifies the observed change;

receiving said event by the client lookup manager; and

updating the associated cache to reflect the observed change.

2. The method of claim 1, further comprising the step of transmitting the event to the client.

3. The method of claim 1, wherein the transmitting an event comprises invoking the callback routine by the lookup service.

4. The method of claim 1, further comprising:

determining that the received event necessitates an update to the associated cache.

5. The method of claim 4, wherein the received event necessitates an update to the associated cache when the associated cache is free of a previously stored instance of the received event.

6. The method of claim 1, wherein the cache is updated to remove all service references to network services that are unique to the lookup service.

7. A non-transitory computer-readable medium containing instructions for controlling a data processing system having a lookup service with associated network services available in a distributed system and having a client computer comprising memory including a client, a client lookup manager and a cache that is locally stored within the memory, the instructions further causing the data processing system to perform a method comprising:

transmitting a request for discovery of at least one lookup service by the client lookup manager;

receiving said request by a discovery server;

transmitting a first object, responsive to the request, to the client lookup manager, wherein the first object provides a reference to at least one lookup service;

receiving said first object by the client lookup manager;

storing the lookup service reference in the cache for subsequent access of the lookup service;

using the reference to register a callback routine with the at least one lookup service;

observing at least one update to the at least one lookup service;

determining that the callback routine has been registered with the lookup service;

transmitting, based on the observing and determining, a second object by the at least one lookup service that identifies the at least one update; and

receiving said second object by at least one of the client and the client lookup manager.

8. The computer-readable medium of claim 7, wherein the method further comprises:

using the lookup service reference to extract a reference to at least one network service; and

storing the extracted network service reference in the cache.

9. The computer-readable medium of claim 8, further comprising before the storing the extracted network service reference in the cache:

determining that the extracted network service is of interest.

10. The computer-readable medium of claim 7, wherein the step of transmitting the first object includes the step of transmitting a null reference to the client lookup manager.

11. The computer-readable medium of claim 10, wherein the method further comprises the step of transmitting a null reference from the client lookup manager to the client.

12. The computer-readable medium of claim 7, wherein the using further includes requesting that the lookup service notify the client lookup manager of a change to its associated network services.

13. The computer-readable medium of claim 12, wherein the method further includes the steps of:

waiting a predetermined period of time until a predetermined quantity of network services are stored in the cache; and

transmitting a plurality of service references to the client.

14. The computer-readable medium of claim 7, wherein the request includes a request to discover new network services.

15. The computer-readable medium of claim 7, wherein the method further comprises:

transmitting a request to the client lookup manager for access to a network service reference; and

searching, in response to the transmitting a request step, the cache to determine if an instance of the requested network service reference is resident within the cache.

16. The computer-readable medium of claim 15, wherein the method further comprises:

returning an instance of the requested network service reference responsive to the instance being resident within the cache, otherwise;

transmitting a request by the client lookup manager to the lookup service for the requested network service reference.

17. The computer-readable medium of claim 7, wherein the request is a multi-cast packet.

18. A non-transitory computer-readable medium containing instructions for controlling a data processing system having a lookup service with associated network services available in a distributed system and having a client lookup manager with an associated cache, the instructions further causing the data processing system to perform a method comprising:

transmitting a request for discovery of at least one lookup service by the client lookup manager;

receiving said request by a discovery server;

transmitting an object, responsive to the request, to the client lookup manager, wherein the object provides a reference to at least one lookup service;

receiving said object by the client lookup manager;

using the reference to register a callback routine with the lookup service by the client lookup manager;

observing, by the at least one lookup service, a change to one of the associated network services;

determining that the callback routine has been registered with the lookup service;

transmitting, based on the observing and determining, an event by the at least one lookup service, said event notifies the client lookup manager of the observed change;

receiving said event by the client lookup manager; and

updating the cache to reflect the observed change.

19. The computer-readable medium of claim 18, wherein the observed change is an addition of a new network service to the lookup service.

20. The computer-readable medium of claim 18, wherein the observed change is a deletion of a network service from the lookup service.

21. The computer-readable medium of claim 18, wherein the observed change is a modification to an attribute of a network service stored on the lookup service.

22. The computer-readable medium of claim 18, wherein the observed change is the removal of a lookup service from the distributed network.