SUMMARYOver the last decade, grid computing has paved the way for a new level of large scale distributed systems where thousands or even millions of heterogeneous, geographically distributed resources can join to provide vast cuantities of integrated computational resources. This powerful capabilities can be used to address computationally challenging scientific problems that could not be faced before, but also provide a new environment where more commercially-oriented ideas could be deployed, such as utility computing or the more recent cloud computing. The grid computing technology developed in the last fifteen years is the natural solution for the developing of these initiatives.But this new step in distributed computing presents also a completely new level of complexity. Management mechanisms play a key role in making grid computing possible, and the correct analysis and understanding of the grid behavior is needed to assure its optimal performance. Usual distributed computing management mechanisms analyze * Correspondence to: jmontes@cesvima.upm.es
FINDING ORDER IN CHAOS: A BEHAVIOR MODEL OF THE WHOLE GRID1 each resource as part of the system and improve global performance by adjusting specific parameters of all of them. Nevertheless, when trying to adapt the same procedures to grid computing the vast heterogeneity and complexity of the system complicates this task.On the other hand, grid heterogeneity and complexity could only be a matter of perspective. Maybe it is possible to analyze and understand the grid behavior as a single system, instead of a set of thousands of them. This abstraction could provide a deeper understanding of the system, describing large scale patterns and global events that could not be detected (or it would be very difficult to) analyzing each resource in a separate way. The subsequent synergy could play the key role in taking grid performance to its peak.In this paper a specific set of techniques is presented and described in order to create a global behavior model of the grid, analyzing it as a single entity. Several real and simulated study cases are also presented, in order to provide a proper validation and illustrate the benefits of this approach.