Stitch – IO Library for highly localized simulations
IO libraries typically focus on writing the entire simulation domain for each output. For many computation classes, this is the correct choice. However, there are some cases where this approach is wasteful in time and space.
The Stitch library was developed initially for use with the SPPARKS kinetic monte carlo simulation to handle IO tasks for a welding simulation. This simulation type has a particular feature where there is computational intensity in a small part of the simulation domain with the rest being idle. Given this intensity, only writing the area that changes is far more space efficient than writing the entire simulation domain for each output. Further, the computation can be focused strictly on the area where the data will change rather than the whole domain. This can yield a reduction from 1024 to 16 processes and 1/64th the data written. These combined can lead to a reduction in the computation time with no loss in data quality. If anything, by reducing the amount written each time, more output is possible.
This approach is also applicable for finite element codes that share the same localized physics.
The code is in the final stages of copyright review and will be released on github.com. A work in progress paper was presented at PDSW-DISCS @ SC18 and a full CS conference paper is planned for H1 2019 and a follow-on materials science journal paper.