Nogood-based asynchronous forward checking algorithms

We propose two new algorithms for solving Distributed Constraint Satisfaction Problems (DisCSPs). The first algorithm, AFC-ng, is a nogood-based version of Asynchronous Forward Checking (AFC). Besides its use of nogoods as justification of value removals, AFC-ng allows simultaneous backtracks going from different agents to different destinations. The second algorithm, Asynchronous Forward Checking Tree (AFC-tree), is based on the AFC-ng algorithm and is performed on a pseudo-tree ordering of the constraint graph. AFC-tree runs simultaneous search processes in disjoint problem subtrees and exploits the parallelism inherent in the problem. We prove that AFC-ng and AFC-tree only need polynomial space. We compare the performance of these algorithms with other DisCSP algorithms on random DisCSPs and instances from real benchmarks: sensor networks and distributed meeting scheduling. Our experiments show that AFC-ng improves on AFC and that AFC-tree outperforms all compared algorithms, particularly on sparse problems.

[1]  C. Yangt,et al.  Constraint Networks: A Survey , 2004 .

[2]  To-Yat Cheung,et al.  Graph Traversal Techniques and the Maximum Flow Problem in Distributed Computation , 1983, IEEE Transactions on Software Engineering.

[3]  Amnon Meisels,et al.  Asynchronous Forward-checking for DisCSPs , 2007, Constraints.

[4]  Katia P. Sycara,et al.  A decentralized variable ordering method for distributed constraint optimization , 2005, AAMAS '05.

[5]  Rina Dechter,et al.  Enhancement Schemes for Constraint Processing: Backjumping, Learning, and Cutset Decomposition , 1990, Artif. Intell..

[6]  Francesca Rossi,et al.  Recent Advances in Constraints (vol. # 3419) : Joint ERCIM/CoLogNET International Workshop on Constraint Solving and Constraint Logic Programming, CSCLP 2004, Lausanne, Switzerland, June 23-25, 2004, Revised Selected and , 2005 .

[7]  Patrick Prosser,et al.  HYBRID ALGORITHMS FOR THE CONSTRAINT SATISFACTION PROBLEM , 1993, Comput. Intell..

[8]  Francesca Rossi,et al.  Recent Advances in Constraints, 12th Annual ERCIM International Workshop on Constraint Solving and Constraint Logic Programming, CSCLP 2007, Rocquencourt, France, June 7-8, 2007, Revised Selected Papers , 2008, CSCLP.

[9]  Milind Tambe,et al.  Argumentation as distributed constraint satisfaction: applications and results , 2001, AGENTS '01.

[10]  Amnon Meisels,et al.  Synchronous vs Asynchronous search on DisCSPs , 2003 .

[11]  Michael J. Quinn,et al.  Taking Advantage of Stable Sets of Variables in Constraint Satisfaction Problems , 1985, IJCAI.

[12]  Boi Faltings,et al.  Asynchronous aggregation and consistency in distributed constraint satisfaction , 2005, Artif. Intell..

[13]  Barr and Feigenbaum Edward A. Avron,et al.  The Handbook of Artificial Intelligence , 1981 .

[14]  Robert M. Haralick,et al.  Increasing Tree Search Efficiency for Constraint Satisfaction Problems , 1979, Artif. Intell..

[15]  Sven Koenig,et al.  BnB-ADOPT: an asynchronous branch-and-bound DCOP algorithm , 2008, AAMAS.

[16]  Ismel Brito.  Synchronous, Asynchronous and Hybrid Algorithms for DisCSP , 2004, CP.

[17]  Makoto Yokoo,et al.  The effect of nogood learning in distributed constraint satisfaction , 2000, Proceedings 20th IEEE International Conference on Distributed Computing Systems.

[18]  Matthew L. Ginsberg,et al.  Dynamic Backtracking , 1993, J. Artif. Intell. Res..

[19]  Youssef Hamadi.  Interleaved backtracking in distributed constraint networks , 2001, Proceedings 13th IEEE International Conference on Tools with Artificial Intelligence. ICTAI 2001.

[20]  Christian Bessiere,et al.  MAC and Combined Heuristics: Two Reasons to Forsake FC (and CBJ?) on Hard Problems , 1996, CP.

[21]  Makoto Yokoo,et al.  An Asynchronous Complete Method for General Distributed Constraint Optimization , 2002 .

[22]  Boi Faltings,et al.  A Scalable Method for Multiagent Constraint Optimization , 2005, IJCAI.

[23]  Makoto Yokoo,et al.  The Distributed Constraint Satisfaction Problem: Formalization and Algorithms , 1998, IEEE Trans. Knowl. Data Eng..

[24]  Boi Faltings,et al.  ODPOP: An Algorithm for Open/Distributed Constraint Optimization , 2006, AAAI.

[25]  Makoto Yokoo,et al.  An asynchronous complete method for distributed constraint optimization , 2003, AAMAS '03.

[26]  Boi Faltings,et al.  Dynamic Distributed BackJumping , 2004, CSCLP.

[27]  M. Silaghi,et al.  Generalized Dynamic Ordering for Asynchronous Backtracking on DisCSPs , 2006 .

[28]  Amnon Meisels,et al.  Message delay and DisCSP search algorithms , 2006, Annals of Mathematics and Artificial Intelligence.

[29]  Leslie Lamport,et al.  Distributed snapshots: determining global states of distributed systems , 1985, TOCS.

[30]  Youssef Hamadi,et al.  Distributed Log-Based Reconciliation , 2006, ECAI.

[31]  Makoto Yokoo,et al.  Algorithms for Distributed Constraint Satisfaction: A Review , 2000, Autonomous Agents and Multi-Agent Systems.

[32]  Milind Tambe,et al.  Taking DCOP to the real world: efficient complete solutions for distributed multi-event scheduling , 2004, Proceedings of the Third International Joint Conference on Autonomous Agents and Multiagent Systems, 2004. AAMAS 2004..

[33]  Eugene C. Freuder,et al.  Constraint - based multi - agent meeting scheduling: Effects of agent heterogeneity on performance a , 2002 .

[34]  Katia P. Sycara,et al.  No-commitment branch and bound search for distributed constraint optimization , 2006, AAMAS '06.

[35]  Christian Bessiere,et al.  Asynchronous backtracking without adding links: a new member in the ABT family , 2005, Artif. Intell..

[36]  Amnon Meisels,et al.  Dynamic Ordering for Asynchronous Backtracking on DisCSPs , 2005, Constraints.

[37]  Carmel Domshlak,et al.  Sensor networks and distributed CSP: communication, computation and complexity , 2005, Artif. Intell..

[38]  Boi Faltings,et al.  Coordinating Logistics Operations with Privacy Guarantees , 2011, IJCAI.

[39]  Shmuel Katz,et al.  On the Feasibility of Distributed Constraint Satisfaction , 1991, IJCAI.

[40]  Christian Bessiere,et al.  DisChoco 2: A Platform for Distributed Constraint Reasoning , 2011 .

[41]  Seif Haridi,et al.  Distributed Algorithms , 1992, Lecture Notes in Computer Science.

[42]  Hosame Abu-Amara.  Fault-Tolerant Distributed Algorithm for Election in Complete Networks , 1988, IEEE Trans. Computers.

[43]  Pedro Meseguer,et al.  Improving ABT Performance by Adding Synchronization Points , 2008, CSCLP.

[44]  Makoto Yokoo,et al.  Distributed constraint satisfaction for formalizing distributed problem solving , 1992, [1992] Proceedings of the 12th International Conference on Distributed Computing Systems.

[45]  Amnon Meisels,et al.  Using additional information in DisCSPs search , 2004 .

[46]  Boi Faltings,et al.  A Value Ordering Heuristic for Local Search in Distributed Resource Allocation , 2004, CSCLP.