This paper presents DynBench, a benchmark suite that is representative of the emerging generation of dynamic real-time distributed systems. The characteristics and architecture of the benchmark application suite are described. Additionally, the paper discusses the DynBench environment, which includes: (1) a technique for specification of "repeatable" dynamic execution scenarios, (2) mechanisms for control (start, stop, replicate and move) of the benchmark applications, (3) interfaces for collection of QoS metrics from the benchmark applications, and (4) an infrastructure for collection of metrics for assessment of adaptive resource management algorithms. The effectiveness of the benchmark for discriminating between good and bad QoS and resource management algorithms is shown via extensive experimentation.