In this paper, we present feedback control techniques for performing adaptive resource management in asynchronous real-time distributed systems. Asynchronous real-time distributed systems are characterized by significant execution-time uncertainties in the application environment and system resource state. Thus, such systems require adaptive resource management that dynamically monitor the system for adherence to the desired real-time requirements and perform run-time adaptation of the application to changing workloads when unacceptable timeliness behavior is observed. We propose adaptive resource management techniques that are based on feedback control theory. The controllers solve resource allocation problems that arise during run-time adaptation using the classical proportional-integral-derivative control functions. We study the performance of the controllers through simulation. The simulation results indicate that the controllers produce low missed deadline ratios and resource utilizations during situations of high workloads.