E ects of Delayed Communication in Dynamic Group Formation

We investigate how delayed communication a ects the dynamic formation of groups in distributed systems, where all decision-making agents join the same group because each expects to improve its own performance. For example, distributed job schedulers may form a group to utilize the idle resources of other members within the group. Forming a group is a search problem and we examine agents which use the feedback mechanism of stochastic learning automata to carry out this search. Although a group formation may have the potential for synergy, the agents must successfully coordinate their actions within the group relevant to the application. For example, job schedulers who form a group must still balance the load among the shared resources; that is, the collective actions of the schedulers need to be coordinated and greedy schedulers who all pick the same processor may not be successful. Agents may nd that working alone is more desirable since their actions need not be coordinated and the results of their own actions are more predictable. An additional challenge to the search problem is to cope with the delay in communication between the agents. The purpose of this study is to model systems where agents adaptively search for compatible co-workers, under the constraint of delayed communication. With insu cient communication, the agents decide to work alone (and receive a modest bene t) but, with su cient communication, the agents make the more advantageous decision to work together.