Abstract: Systems and methods for run-time monitoring, tuning and optimization of distributed systems are provided. In various aspects, a system or method may include measuring run-time values for one or more performance metrics of the distributed system, such as, for example, task-latencies, process-throughputs, and the degree of utilization of various physical resources of the system. The system or method may further include comparing the measured run-time values with one or more target values assigned to the performance metrics, and, based on the comparison, adjusting one or more tunable run-time control variables of the distributed system, such as the number of the tasks, processes, and nodes executing in the distributed system.