Hello, A new project on the LCRC cluster has been requested. Please forward the information on to the LCRC Allocation sub-committee. Applicant's name: Jay Larson Applicant's institution: ANL Applicant's division: MCS Project Name: CouplingMechOpt Project title: Mechanics and Optimization of Coupling in Multiphysics and Mulitscale Systems Associated funding: DOE Other Systems: ALCF Science: The objectives of this project are to explore Study (and implement) mechanisms generally useful Study, prototype, and (with hope!) implement in production infrastructure useful to coupled systems, including: * Schemes for intercomponent load balance, including load diagnostics, and mechanisms for addressing intercomponent load imbalances through malleability of component cohorts * Studies detailing intercomponent data dependencies in parallel coupled and performance measurement and modeling to inform load balance, component cohort sizing, and * Simulators of large coupled systems to forecast coupled model throughput Project description: Coupled systems--both multiscale and multiphysics--are increasingly relevant to modeling for basic scientific research and for highly applied engineering applications. The advent of ultrascale platforms comprising up to million-way parallelism begs the question: What kind of applications are amenable to this monumental computational capability, and how might we use this unprecedented computational power efficiently? Multiphysics and multiscale models comprising multiple subsystems in mutual interaction are a likely application for these platforms. The challenge then becomes developing infrastructure for managing what are likely to be time-evolving component loads while minimizing processor idle time in components awaiting coupling input from other components. As a first step towards a solution for intercomponent load management for parallel coupled models, we are developing a mechanism for multicomponent load management that includes support for dynamical resizing of component cohorts at runtime. The framework is built to complement and extend the Model Coupling Toolkit (MCT; http://mcs.anl.gov/mct), key coupling middleware used most notably in the Community Climate System Model. The resource requested is for prototyping of the aforementioned intercomponent load management system, and extensive sanity and performance testing of the system in a set of use cases ranging from simple “toy” problems up to (assuming all goes well) a coupled climate model such as CCSM. MCT is highly portable and routinely compiles/runs on fusion. MCT uses MPI and any Fortran compiler available on fusion. We expect we may need only minimal system consulting support to perform the work outlined. We are requesting access to fusion so that we have a medium-sized cluster to test out ideas and code. Typical job sizes would require small numbers of processors (<=64) for periods of 15 minutes or less; larger jobs would run for correspondingly shorter periods. Project URL: http://mcs.anl.gov/mct Requested allocation: 30000 Justification: N/A The requester has used 0 hours of their initial startup project. In addition to approving an initial amount, please specify a Category and Subcategory for this project. For a list of the current selection of approved categories, please see: https://wiki.lcrc.anl.gov/wiki/Processes/Categories Once the Allocation committee has approved the project, please go to the Project Management page to create it: https://accounts.lcrc.anl.gov/projects.php Thank You, The LCRC Accounts System