Level-2 Milestone 4468: Lorenz Simulation Interface Beta Release

Abstract

The goal of Lorenz is to develop a sophisticated web-based framework as a front end to Livermore Computing Center resources. The primary features include: a personalized dashboard for each user, giving an at-a-glace overview of all computing center resources; a front-end to job submission and management; and a software framework to extend the convenience of web interfaces into simulation codes, including support for setting up, launching, steering, and monitoring simulations. Because the breadth of desktop operating systems in use both inside and outside LLNL spans all flavors of Linux, Mac, and Windows, the decision was made to use exclusively web-based technologies in Lorenz. Recent advancements in AJAX and Javascript programming, along with coming advances in the form of HTML5 and CSS3, made the browser the preferred development platform. The goal is to provide the user with a robust application interface that requires nothing more than a modern, standards-based web browser. This approach not only provides convenient access to Lorenz for internal and external users, but also has significant advantages over conventional applications in terms of rapid deployment and updates. The first phase of the Lorenz project is a system “dashboard”, known as MyLC, that gives LC users a rich set of portal applications, or “portlets”, from which to choose. Information that previously required knowledge of dozens of different commands, files, and web pages is now available in one convenient location. This includes account information, bank and disk usage, quotas, cluster utilization, news items, active jobs on LC systems, and more. The extensible software design of the dashboard allows users and staff members to develop their own portlets, and for them to be shared with all users or just within work groups. The second major phase of Lorenz was built on the idea that HPC centers are managed around batch processing, and “jobs” (or “runs”) progress through several discrete stages: setup, submission, queuing/waiting, running, completion, analysis, and archiving. Lorenz aims to ultimately tie all of these pieces together, including integration with the dashboard and application portals. In addition to helping guide users through the process of defining batch parameters, monitoring job progress, and interacting with jobs and job output, Lorenz also aims to promote access to additional tools and capabilities which to this point have been limited to use by power users. Ultimately Lorenz will assist users in choosing the appropriate resources, such as cluster and file system, given the requirements of a job. The third major phase of Lorenz, the subject of this milestone, is the development of an application portal. This involves teaming with application codes to provide a simple graphical interface to the simulations, which in turn seamlessly ties into job submission and monitoring. This will allow users to directly define simulation parameters and launch applications using a simple but powerful web front-end. Because many complex multi-physics codes can have thousands of inputs, providing a general GUI for building an input deck from scratch is impractical. However, most users of large applications start with an existing input file, and make some number of small changes to it. The application portal will feature a process that combines trusted and validated input files with a GUI that guides the user toward making the relatively minor changes needed for their particular problem. The input files will be in the form of templates, containing most of the data needed for a particular problem along with parameterization of changeable inputs. For expert users, there ultimately will be a way to edit the final input file directly - in the event that there are input changes needed that were not captured in the GUI.