Truthful algorithms for scheduling selfish tasks on parallel machines
نویسندگان
چکیده
We consider the problem of designing truthful mechanisms for scheduling selfish tasks (or agents)—whose objective is the minimization of their completion times—on parallel identical machines in order to minimize the makespan. A truthful mechanism can be easily obtained in this context (if we, of course, assume that the tasks cannot shrink their lengths) by scheduling the tasks following the increasing order of their lengths. The quality of a mechanism is measured by its approximation factor (price of anarchy, in a distributed system) w.r.t. the social optimum. The previous mechanism, known as SPT, produces a (2 − 1/m)-approximate schedule, wherem is the number ofmachines. The central question in this paper is the following: “Are there other truthful mechanisms with better approximation guarantee (price of anarchy) for the considered scheduling problem?” This question has been raised by Christodoulou et al. [Coordination mechanisms, in: Proc. of ICALP 2004, Lecture Notes in Computer Science,Vol. 3142, 345–357.] in the context of coordination mechanisms, but it is also relevant in centrally controlled systems. We present (randomized) truthful mechanisms for both the centralized and the distributed settings that improve the (expected) approximation guarantee (price of anarchy) of the SPT mechanism. Our centralized mechanism holds for any number of machines and arbitrary task lengths, while the coordination mechanism holds only for two machines and task lengths that are powers of a certain constant. © 2006 Elsevier B.V. All rights reserved.
منابع مشابه
Scheduling Selfish Tasks: About the Performance of Truthful Algorithms
This paper deals with problems which fall into the domain of selfish scheduling: a protocol is in charge of building a schedule for a set of tasks without directly knowing their length. The protocol gets these informations from agents who control the tasks. The aim of each agent is to minimize the completion time of her task while the protocol tries to minimize the maximal completion time. When...
متن کاملTruthfulness for the Sum of Weighted Completion Times
We consider the problem of designing truthful mechanisms for scheduling selfish tasks on a single machine or on a set of m parallel machines. The objective of every selfish task is the minimization of its completion time while the aim of the mechanism is the minimization of the sum of weighted completion times. For the model without payments, we prove that there is no (2 − )-approximate determi...
متن کاملTruthful Mechanisms for Scheduling Selfish Related Machines Using ACO
Task scheduling is a major challenge in parallel and distributed systems. Task scheduling techniques in distributed systems are usually based on trusting the Accuracy of the information about the status of resources. In a commercial multiCloud environment, individual providers are focused towards increasing their own profits and do not care about the utility of users and other providers. In suc...
متن کاملOn Designing Truthful Mechanisms for Online Scheduling
We study the online version of the scheduling problem Q||Cmax involving selfish agents, considered by Archer and Tardos in [FOCS 2001], where jobs must be scheduled on m related machines, each of them owned by a different selfish agent. We present a general technique for transforming competitive online algorithms for Q||Cmax into truthful online mechanisms with a small loss of competitiveness. ...
متن کامل