Asynchronous Provisioning Strategy for Heterogeneous Grids

Following upon the infrastructure and architecture discussed in the former chapters, this chapter proposes a distributed and asynchronous model in our Guardian maintenance system for dynamic provisioning that is well-suited to such an intricate setting. The solution introduces multiple maintaining layers so that all the maintenance instructions can be done in an asynchronous way. Experimenting with the new model, in which maintenances are executed in an interlaced time sequence, the downtime of the global system during service maintenance can be effectively reduced by preventing a Weakest Link Effect usually arising from individual heterogeneity or emergent faults. Thus, the consistency of alien nodes and the execution of new requests (after maintenance) can be guaranteed simultaneously. In particular, the implications of maintenance due to heterogeneous dependencies can be detected and resolved automatically in this framework. The practical evaluations prove that the Guardian system equipped with this model can improve the availability and reduce downtime effectively.