Dynamic program modification in the non-stop software extensible system (NOSES)

Abstract

This paper presents a mechanism for partially modifying programs written in a high-level language without interrupting service of a switching or communication system. This mechanism is developed as a part of our plan for establishing the non-stop software extensible system (NOSES). This dynamic program modification method covers 100% of bug fixes and most minor feature additions. By considering the relationship of the modification mechanism and the characteristics of the modified program, we clarify conditions for preventing inconsistencies. We also examine the off-line system, the on-line OS kernel, and simple operation interface. Our mechanism is expected to be used widely in switching or communications systems.<>