Dynamic resource allocation for efficient parallel CFD simulations

TL;DR

This paper introduces an adaptive runtime resource management method for parallel CFD simulations, optimizing resource use based on communication efficiency to improve performance and reduce waste.

Contribution

It proposes a novel elastic computing approach that dynamically adjusts resources during simulation based on communication efficiency metrics.

Findings

Resource allocation adapts in real-time to maintain efficiency

Reduces computational waste by avoiding over-provisioning

Improves overall parallel simulation performance

Abstract

CFD users of supercomputers usually resort to rule-of-thumb methods to select the number of subdomains (partitions) when relying on MPI-based parallelization. One common approach is to set a minimum number of elements or cells per subdomain, under which the parallel efficiency of the code is "known" to fall below a subjective level, say 80%. The situation is even worse when the user is not aware of the "good" practices for the given code and a huge amount of resources can thus be wasted. This work presents an elastic computing methodology to adapt at runtime the resources allocated to a simulation automatically. The criterion to control the required resources is based on a runtime measure of the communication efficiency of the execution. According to some analytical estimates, the resources are then expanded or reduced to fulfil this criterion and eventually execute an efficient simulation.