Scheduling periodic I/O access with bi-colored chains: models and algorithms

Ordonnancement d'entrées/sorties périodiques avec des chaînes bicolores: modèles et algorithmes

Emmanuel Jeannot (1) , Guillaume Pallez (1) , Nicolas Vidal (1)

1 TADAAM - Topology-Aware System-Scale Data Management for High-Performance Computing

Observations show that some HPC applications periodically alternate between (i) operations (computations, local data-accesses) executed on the compute nodes, and (ii) I/O transfers of data and this behavior can be predicted beforehand. While the compute nodes are allocated separately to each application, the storage is shared and thus I/O access can be a bottleneck leading to contention. To tackle this issue, we design new static I/O scheduling algorithms that prescribe when each application can access the storage. To design a static algorithm, we emphasize on the periodic behavior of most applications. Scheduling the I/O volume of the different applications is repeated over time. This is critical since often the number of application runs is very high. In the following report, we develop a formal background for I/O scheduling. First, we define a model, bi-colored chain scheduling, then we go through related results existing in the literature and explore the complexity of this problem variants. Finally, to match the HPC context, we perform experiments based on use-cases matching highly parallel applications or distributed learning framework

Mots clés: High performance computing; complexity; algorithmics; approximations

Domaines: Calcul parallèle, distribué et partagé [cs.DC]; Algorithme et structure de données [cs.DS]; Complexité [cs.CC]

Emmanuel Jeannot, Guillaume Pallez, Nicolas Vidal. Scheduling periodic I/O access with bi-colored chains: models and algorithms. Journal of Scheduling, inPress, ⟨10.1007/s10951-021-00685-8⟩. ⟨hal-03216844⟩