HUBzero’s Variations of Sustainability: From Simulation/Modeling Tools to Communities

Sustainability of science gateways and continuous funding for their developer teams is a major concern that many projects face. The HUBzero® project and its science gateway framework have evolved to be self-sustained via diversifying funding resources, extending outreach measures to further communities and targeting sustainability from different angles in concrete instances. nanoHUB, PURR and OneSciencePlace are examples of how the HUBzero® team and platform build science gateways and take their specific services into account to address sustainability beyond securing funding and outreach activities. They have been integrating additional procedures and concepts for sustainability: nanoHUB invests into reliability of the over 500 simulation tools and high quality lecture and tutorial content to keep the trust of the large community with over 1.5 million users; PURR developed policies and methods for preserving research output in a sensible and sustainable way and OneSciencePlace addresses the concern of projects that have a lack of continuous funding for maintaining a science gateway by offering a solution to keep science gateways available to their communities. The paper goes into detail for measures for sustainability for HUBzero® and especially for nanoHUB, PURR and OneSciencePlace. Keywords—HUBzero®; nanoHUB; PURR; OneSciencePlace; science gateways; sustainability; research content; research frameworks INTRODUCTION The importance of sustainability of research software in general and thus of science gateways as subgroup has been recognized by various researchers, funding bodies and organizations evident in funded projects such as the Science Gateways Community Institute (SGCI) [1] and the UK Software Sustainability Institute (SSI) [2] as well as initiatives such as the Research Software Engineer (RSE) Association in the UK [3] and the RSE Communities in Germany and in the US [4]. There are many definitions for sustainability of software available, i.e. SSI states in their manifesto “Sustainability means that the software you use today will be available and continue to be improved and supported in the future.” [5]. C.C. Venters et al. [6] define software sustainability as a composite, nonfunctional requirement which is “a measure of a systems extensibility, interoperability, maintainability, portability, reusability, scalability, and usability”. Most definitions consider maintainability, fulfilling its purpose over time and surviving uncertainty as essential characteristics for sustainable software. Achieving sustainability based on these three characteristics requires continuous effort and a variety of actions by a project and/or group developing software or a science gateway, respectively. In the remainder of the paper we focus on science gateways and the science gateway landscape to define the variations of actionable items. Science gateways are created for specific communities and are embedded in the science gateway landscape with similar Copyright © 2021 for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0). 11 International Workshop on Science Gateways (IWSG 2019), 12-14 June 2019 and/or competing science gateways. Existing mature frameworks and APIs such as HUBzero® [7], Galaxy [8] and the Agave Platform [9] allow for creating science gateways more efficiently and support developers on focusing on a specific gateway while offering features such as connecting to distributed computing out of the box. The services of science gateways vary from offering simulations tools to data collections to computational workflows with different requirements on the user interface and the underlying research infrastructure. The services and the target communities of various science gateways might be very different from each other, but actionable items can be determined in a similar way. We distinguish four key variations for actionable items: 1. a technical area, 2. a community area, 3. a science gateway landscape area and 4. a stakeholder or funding area. Examples for action items for the areas include 1. Use of well-defined software engineering practices to support extensibility, interoperability, maintainability, portability, reusability, scalability, usability, reliability and security 2. Support measures and extension of features and/or technologies in a science gateway driven by the needs of a community 3. Outreach and expansion to new communities 4. Diversifying funding The areas are not isolated from each other but influence and overlap with each other. For example, after analyzing the science gateway landscape and reaching out to a new promising community, the development of a novel science gateway necessitates the technical implementation based on gathering requirements from the community. The definition of concrete actionable items is a mixture of performing analyses and tasks in all four areas. The HUBzero® project has been achieving sustainability for its science gateway framework and the team via multiple measures. The science gateway framework started in 1996 as online platform PUNCH [10] for nanoelectronic research and teaching. It was horizontally expanded for more simulation tools to nanoHUB [11] and vertically to HUBzero® to serve as generic science gateway framework for a variety of communities. These expansions led to novel developments on technical side. Reaching out to communities includes the participation in conferences and workshops as presenters and/or sponsor, social media such as Twitter and a yearly event that offers the opportunity to clients to interact with the HUBzero® team face-to-face. The financial independence of the developer team from funding provided by the Purdue University was a major step. It has been attained by diversifying funding resources with participation in grants, offering hosting services and offering memberships in the HUBzero® foundation, which allow supporting instances with a limited number of development time and consultancy for usability and community outreach measures specifically for the instance. Examples for action items in nanoHUB, PURR, and OneSciencePlace are described in detail in the sections III – V after presenting the background for activities to reach sustainability for science gateways.