Enabling scientific workflow and gateways using the standards-based XSEDE architecture

The XSEDE project seeks to provide “a single virtual system that scientists can use to interactively share computing resources, data and experience.” The potential compute resources in XSEDE are diverse in many dimensions, node architectures, interconnects, memory, local queue management systems, and authentication policies to name a few. The diversity is particularly rich when one considers the NSF funded service providers and the many campuses that wish to participate via campus bridging activities. Resource diversity presents challenges to both application developers and application platform developers (e.g., developers of gateways, portals, and workflow engines). The XSEDE Execution Management Services (EMS) architecture is an instance of the Open Grid Services Architecture EMS and is used by higher level services such as gateways and workflow engines to provide end users with execution services that meet their needs. The contribution of this paper is to provide a concise explanation and concrete examples of how the EMS works, how it can be used to support scientific gateways and workflow engines, and how the XSEDE EMS and other OGSA EMS architectures can be used by applications developers to securely access heterogeneous distributed computing and data resources.