Streaming Latency refers to the end-to-end delay experienced by a data event as it travels through a stream processing system. It measures the time taken from the moment an event is generated by a source system (or ingested into the streaming platform) until the moment its processed output (e.g., an updated metric, a triggered alert, a record in a sink system) is available and visible to a downstream consumer or application.
Minimizing latency is a critical goal for most real-time stream processing applications, as it directly impacts the freshness of insights and the responsiveness of systems relying on the processed data.
Streaming latency is an aggregate of several individual delays encountered at different stages of the pipeline:
Latency and throughput are often competing goals. Optimizing solely for minimal latency might involve processing each event individually, which can reduce throughput. Conversely, optimizing for maximum throughput often involves batching or buffering, which can increase latency. A common challenge is to find the right balance for the specific application requirements.
RisingWave is designed to achieve low latency by processing data incrementally and efficiently managing state for continuous computations.