Enabling Autonomic System Software with Hot-Swapping

Autonomic computing systems are designed to be self-diagnosing and self-modifying, such that they notice performance and correctness problems, pinpoint their causes, and react accordingly. These abilities can increase performance, uptime, and security, while simultaneously reducing the effort and knowledge required of system administrators. One way that systems can support these abilities is by allowing monitoring code, diagnostic code, and function implementations to be dynamically inserted and removed in live systems. This “hot swapping” University of Toronto, Dept of Computer Science Carnegie Mellon University IBM T. J. Watson Research Center SOMA Networks, Inc. IBM Beaverton Univ of Toronto, Dept of Electrical and Computer Engineering approach avoids the requisite prescience and additional complexity inherent in creating systems that have all possible configurations built in ahead of time. For already-complex pieces of code such as operating systems, hot-swapping provides a simpler, higher performance, and more maintainable method of achieving autonomic behavior. This paper describes an aspect of autonomic computing for systems software using hotswapping. We describe its advantages and system structure requisite for hot-swapping. The K42 Operating System (OS) explicitly supports interposition and replacement of active OS code. We describe K42’s infrastructure and give examples from our research work demonstrating autonomic behavior.