Exploring Phantom Jams in your Data Flow
Blog post from ScyllaDB
The concept of "phantom jams" in data flow is explored through a comparison to traffic waves, where data slowdowns occur for no apparent reason, despite the absence of bottlenecks. This phenomenon is examined using the Producer-Dispatcher-Consumer model, where a Dispatcher manages message flow between a Producer and a Consumer, potentially causing delays if not optimally configured. Through simulation, it is shown that jitter in the Dispatcher has the most significant impact on system performance, compared to jitter in the Producer or Consumer, affecting both message latency and throughput. The study emphasizes the importance of understanding and monitoring system components to mitigate these effects, especially highlighting the role of the Dispatcher’s effective dispatch rate, which is influenced by dispatch frequency and over-dispatching multiplier. This research underscores the need for careful system architecture and monitoring to prevent inefficiencies in data-intensive applications like those managed by ScyllaDB, a highly performant NoSQL database.