Kais Klai | Searcharxiv

arXiv2015

Time Petri Net Models for a New Queuless and Uncentralized Resource Discovery System

In this report, we detail the model using Petri Nets of a new fully distributed resource reservation system. The basic idea of the considered distributed system is to let a user reserve a set of resources on a local network and to use them, without any specific, central administration component such as a front-end node. Resources can be, for instance, computing resources (cores, nodes, GPUs...) or some memory on a server. In order to verify some qualitative and quantitative properties provided by this system, we need to model it. We detail the algorithms used by this system and the Petri Net models we made of it.

cs.DC↗

arXiv2011

Combining Explicit and Symbolic Approaches for Better On-the-Fly LTL Model Checking

We present two new hybrid techniques that replace the synchronized product used in the automata-theoretic approach for LTL model checking. The proposed products are explicit graphs of aggregates (symbolic sets of states) that can be interpreted as Büchi automata. These hybrid approaches allow on the one hand to use classical emptiness-check algorithms and build the graph on-the-fly, and on the other hand, to have a compact encoding of the state space thanks to the symbolic representation of the aggregates. The Symbolic Observation Product assumes a globally stuttering property (e.g., LTL \ X) to aggregate states. The Self-Loop Aggregation Product} does not require the property to be globally stuttering (i.e., it can tackle full LTL), but dynamically detects and exploits a form of stuttering where possible. Our experiments show that these two variants, while incomparable with each other, can outperform other existing approaches.

cs.LO↗