Grid resource management with service level agreements

With Grid computing adopting Service Oriented Architecture (SOA), resources are represented by services with standardized interfaces and the management of resources converges to the more general management of services (i.e. the Service Level Management). The key to Service Level Management is the management of Service Level Agreement (SLA), a formal contract between the provider and consumer of a service which stipulates and commits the provided service to a required level of service. We concentrate in our research on designing and establishing an infrastructure for SLA management. It consists of a site-local infrastructure for managing SLAs and local resources, and a global infrastructure for advertising and brokering of resources. From the client’s point of view, a typical session of service usage includes the following activities: the client sends job parameters and SLA parameters (such as deadline, price etc.) to the broker, the broker contacts the service sites to get available SLA templates, the broker selects the appropriate template and sends it to the client for verification and an acknowledgement is represented by the return of a signed SLA offer. The SLA offer is then forwarded by the broker to the corresponding service site to create the SLA. With the negotiated SLA, the client invokes the service and gets an id (endpoint reference) of the job. According to the negotiated SLA, the job is scheduled at appropriate time and as soon as the job finishes, a notification is sent to the client so that the result can be retrieved. On the service site, a service has an associated management infrastructure that handles the management of SLAs and resources. The WS-Agreement services provide interfaces for requests for SLA templates, SLA creation and termination, notification of SLA status changes etc. The performance predictor estimates resource demands for specific values of job parameters, and the resource manager keeps track of resource capabilities and job schedules. Based on the information provided by both, the agreement decision maker decides on the acceptance or rejection of a specific SLA offer. The resource manager (together with the underlying scheduler) is also responsible for the scheduling of jobs with resource reservation and service invocation at scheduled time. Targeting to the SLA-based resource management infrastructure, we focus on the fundamental issues for the establishment of such an infrastructure, including the specification of SLAs with WS-Agreement and the design and implementation of a generic and extensible support infrastructure for WS-Agreement specification, the evaluation of various techniques for application performance prediction and the establishment of a generic infrastructure for non-intrusive monitoring and adaptive prediction of the execution time of