|Monday, June 2|
|2:00 pm - 3:30 pm|
Dynamic Service Level Agreements (2/2)
Karim Djemame (University of Leeds, UK), Omer Rana (Cardiff University, UK), Wolfgang Ziegler (Fraunhofer SCAI, Germany), Phillip Wieder (University of Dortmund, Germany)
Grid computing systems need to achieve levels of Quality of Service (QoS) necessary for enterprise applications in science and industry. A Service Level Agreement (SLA) specification provides a formal method for describing QoS requirements. This workshop seeks to bring together researchers and engineers whose organisations are actively addressing SLAs concerns, for example through WS-Agreement standardisation, to share experiences and describe their research in order to facilitate better understanding of Grid QoS issues and requirements. SLAs become particularly important in the context of emerging computing infrastructure such as Cloud Computing. Within such infrastructure, it is necessary for providers to establish SLAs within a Cloud to ensure that some acceptable level of quality can be offered to an external user. Examples of this can be seen in the Amazon S3 and EC2 Cloud services, where Amazon offers SLAs defined in terms of uptime and availability for their Cloud services, even though the Cloud itself is implemented through a distributed data center managed by Amazon. We believe therefore that as Grids evolve towards the Cloud and "ensemble" computing concept (from Irvin Wladawsky-Berger's talk at OGF22), SLAs will gain greater significance, especially the focus on negotiation mechanisms to support SLA formation and subsequent use.
In recent years, it has become clear that there is considerable overlap between the goals of Grid computing and the benefits of an SOA based on Web services; the rapid advances in Web services technology and standards have thus provided an evolutionary path from the architecture of current Grids to the standardised, service-oriented, enterprise-class Grid of the future.
Grid Service Level management contains QoS descriptions for Web services in the form of SLAs and support infrastructures and tools for service design, design validation and run-time verification. SLAs are formal contracts negotiated between end-users and service providers. WS-Agreement is a language and protocol designed for advertising the capabilities of providers and creating agreements based on initial offers, and for monitoring agreement compliance at runtime. The motivations for the design of WS-Agreement stem out of QoS concerns. The definition of the protocol is totally general and allows for the negotiation of QoS in any Web service enabled distributed system. However, the WS-Agreement specification does not contemplate the possibility of changing an agreement at runtime. Therefore the challenge is to provide extensions of WS-Agreement and of its semantics in order to make agreements robust and more long-lived to individual term violations.
This workshop will seek to bring together researchers and engineers working on SLA issues in order to facilitate better understanding of requirements for QoS provision of Grid systems. Two considerations will merit special attention. First, Grid SLA management is complicated by the inherent composition of the Grid. Second, commercial Grids are identified as an emerging specialisation of Grid technology, therefore a fundamental requirement is the need to define and satisfy SLAs. An important focus of this workshop will be on how SLA management systems and Grid standards currently being developed can specify, negotiate, monitor and adapt SLAs to provide a level of QoS needed for scientific and industrial purposes. The workshop will address techniques and mechanisms employed by, or being considered for, current Grid systems to manage SLAs to ensure QoS provision. These include, but are not limited to, SLA specification, SLA negotiation, SLA re-negotiation, WS-Agreement extensions, QoS monitoring. Of special interest is the relationship of these mechanisms to, and interactions with, specifications being developed within OGF (GRAAP) and related organisations, for example for Grid middleware services.
2:00 - 2:05 Opening
2:05 - 2:25 BREIN
2:25 - 2:45 SLA@SOI
2:45 - 3:05 AssessGrid
3:05 - 3:25 RESERVOIR (to be confirmed)
3:25 - 3:30 Closing
Location: Barcelona B
| Slides: On the Use of Service Level Agreements in AssessGrid|
| Slides: SLA@SOI: Research Perspectives for Dynamic SLA Management|
| Slides: Workshop Programme|