Thesis Defense - Griff

Many of today's software applications are of a distributed nature and are being designed and implemented by general programmers. Distributed object models are well suited to these applications and provide a layer of abstraction to the developer. By creating an object interface layer to the applications distribution layer, developers can use a framework for creating distributed systems without needing detailed knowledge of the distribution layer mechanisms.

Many distributed object systems are designed with location and update transparency as a means of sheltering the developer from implementation details. In this dissertation, mechanisms have been identified, designed, implemented, and analyzed that enable transparent distributed object subsystems to utilize application level hints in order to dynamically customize object location and caching policies. A distributed object management system has been built as a proof of concept system to study the performance of explicit location and caching policies.

The methodology for tailoring object location and caching policies in the subsystem is performed at an abstract level using Gryphon agents, which provide an auxiliary interface to existing distributed object subsystems, thereby eliminating the developers need to tune performance at the low-level distribution layer. In the best case, applications using a Gryphon enhanced subsystem reduce the message traffic down to a fraction of a percent compared to unenhanced subsystems and eliminate access latencies to objects existing or cached locally, and in the worst case the performance is no worse than with the unenhanced subsystem.