Real-time information dissemination is of increasing importance to our society. Existing work mainly focuses on delivering information from sources to sinks in a timely manner based on established subscriptions, with the assumption that those subscriptions are persistent. However, the bottleneck of many real-time information dissemination systems is actually the matching process to continuously reevaluate such subscriptions between numerous sources and numerous sinks, in response to dynamically varying information attributes at runtime. In this paper, we propose a feedback controller to adaptively meet the response time constraints on metadata matching in an example information dissemination system. Our controller features a rigorous design based on well-established feedback control theory for guaranteed control accuracy and system stability. Empirical results on a physical test-bed demonstrate that our controller outperforms both an open-loop solution and a typical heuristic solution...