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Flexible lease policies for networked services/resources

IP.com Disclosure Number: IPCOM000015435D
Original Publication Date: 2002-Jun-13
Included in the Prior Art Database: 2003-Jun-20
Document File: 6 page(s) / 113K

Publishing Venue

IBM

Abstract

This concept concerns a new system for monitoring leases in a networked environment. Some network services, such as databases, backup, video-on-demand, etc., involve the allocation of resources. These resources include disk space in the case of the database and backup services, network QoS in the case of video-on-demand, and the control of camera in the of face detection services. The implementation of these services can be greatly simplified if it is based on a generic lease service, which controls the allocation of the resources and negotiates the leasing parameters (eg 5 GB of disk for X minutes, the total control of the camera for Y seconds, transmission of video V with a bit rate B, etc). This generic lease service can be registered in a service lookup database, such as UDDI (http://www.uddi.org), so that services that require the allocation of resources can find and use it. In this way the same generic lease service can be reused among several applications. Figure 1 illustrates this architecture.

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Flexible lease policies for networked services/resources

  This concept concerns a new system for monitoring leases in a networked environment. Some network services, such as databases, backup, video-on-demand, etc., involve the allocation of resources. These resources include disk space in the case of the database and backup services, network QoS in the case of video-on-demand, and the control of camera in the of face detection services. The implementation of these services can be greatly simplified if it is based on a generic lease service, which controls the allocation of the resources and negotiates the leasing parameters (eg 5 GB of disk for X minutes, the total control of the camera for Y seconds, transmission of video V with a bit rate B, etc). This generic lease service can be registered in a service lookup database, such as UDDI (http://www.uddi.org), so that services that require the allocation of resources can find and use it. In this way the same generic lease service can be reused among several applications. Figure 1 illustrates this architecture.

1. FindDatabase

lease service

Backup

UDDI registry

 Face detection

2. Use the lease service as a component

Lease service

Figure 1. Lease service as a component of several networked applications

Application Scenarios

The generic lease service is based on a lease manager, which controls the lease for several applications/Web services. Let us consider the example of a database service that leases its resources (disk space) to clients. Instead of implementing the leasing mechanism by itself, it can register with the generic lease service and let it handle this task. After that, when clients want to start using the database they have to contact the lease service first and negotiate the lease contract. At this point the lease service passes the contract information to the database, which can either accepted or deny it. Once the client and the database agree on the lease contract they can start interacting. When the lease expires, if it is not renewed, the lease manager notifies the database, which can then take the appropriate action (eg remove all the information that client has written). Figure 2 illustrates this sequence of interaction.

1

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Client

Lease Databaseservice

lease

negotiate lease

accept

accept

Sequence of database operations

When lease notifyexpires Database

Updates database

Deletes client information

Figure 2. Interactions between clients, the lease service, and a database service

One of the key aspects here is that the lease contract is not based only on time, like in the Sun Jini model where a resource can only be exclusively leased for a period of time. Here, the lease can be based on several parameters, therefore resources can be leased partially, such as in the case of the database where it can lease X GB of space for Y hours. However, the lease manager only controls the leasing time. All the othe...