language: en

Spheres of Control: An Approach to Advanced Recovery

C. Wallace N. Soparkar
Electrical Engineering & Computer Science The University of Michigan
Ann Arbor, MI 48109-2122 USA
fwallace,soparkarg@eecs.umich.edu

Abstract Recovery from failures and erroneous executions is a crucial but complicated issue for concurrently accessed data systems. Increasingly sophisticated techniques are being developed to improve performance and functionality of recovery protocols. To better understand and analyze recovery schemes, we reexamine the concept of spheres of control [Dav78], using it as a unifying framework for specifying diverse recovery models simply and precisely. We constrain sphere-of-control formulations appropriately to capture transaction-oriented recovery in both centralized and distributed environments and with different types of schedules, as well as semantics-based recovery and compensation. In addition, we discuss how the operational semantics methodology of evolving algebras [Gur95] can model spheres of control formally and refine them to lower levels of abstraction.

1 Introduction