A WS-Agreement-Based QoS Auditor Negotiation Mechanism for Grids

High performance platforms composed of commodity computing resources, such as grids and peer-to-peer systems, have greatly evolved and assumed an important role in the last decade. Nevertheless, their wide commercial use still depends on the establishment of an effective quality of service (QoS) infrastructure in those environments. For this reason, a variety of proposals have recently emerged in which consumer and provider monitor and control grid resources in order to guarantee previously established service level agreements. However, in many cases there is lack of trust between provider and consumer in relation to monitoring those agreements. In such cases, it becomes necessary to introduce a third entity - an impartial and trustworthy QoS auditor - in order to solve conflicts of interest. Though, as there may be several auditors trusted by provider and consumer, we claim that the QoS auditor needs to be negotiated and established just as the service level agreement is negotiated by the parties. In order to support this issue, the present paper proposes and evaluates a negotiation mechanism for QoS auditors in computational grids. Some of the proposed mechanism's characteristics are low intrusiveness and use of open standards, such as the WS-Agreement. Experimental analysis on a prototype of the proposed negotiation mechanism have shown that the auditor negotiation process took less than a minute to finish, which is far less than the service execution time in most grid computing use cases.