Multi-trials technique

The Multi-Trials technique by Schneider et al. is employed for distributed algorithms and allows to break symmetries efficiently. Many message passing algorithms typically employ one attempt to break symmetry per message exchange. The Multi-Trials transcends this approach through employing more attempts with every message exchange.

For example, in a simple algorithm for computing an O(Δ) vertex coloring, where Δ denotes the maximum degree in the graph, every uncolored node randomly picks an available color and keeps it if no neighbor (concurrently) chose the same color. For the Multi-Trials technique, a node gradually increases the number of chosen colors in every communication rounds. The technique can yield more than an exponential reduction in the required communication rounds.

References

• Schneider, J. (2010), "A new technique for distributed symmetry breaking", Proceedings of the [[Symposium on Principles of Distributed Computing]] (PDF) {{citation}}: URL–wikilink conflict (help)
• Schneider, J. (2008), "A log-star distributed maximal independent set algorithm for growth-bounded graphs", Proceedings of the [[Symposium on Principles of Distributed Computing]] (PDF) {{citation}}: URL–wikilink conflict (help)