streaming - 99% 延迟和吞吐量的含义是什么

Question

我读过一些文章，对 Spark 流、Storm 和 Flink 等流处理引擎的性能进行基准测试。在评估部分，标准是第 99 个百分位数和吞吐量。例如，Apache Kafka 以每秒大约 100.000 个事件的速度发送数据，这三个引擎充当流处理器，它们的性能使用 99% 的延迟和吞吐量来描述。

任何人都可以为我澄清这两个标准吗？

Answer 1

流作业中 X 毫秒的第 99 个百分位延迟意味着 99% 的项目在不到 X 毫秒内到达管道末端。阅读this reference了解更多详情。

When application developers expect a certain latency, they often need a latency bound. We measure several latency bounds for the stream record grouping job which shuffles data over the network. The following figure shows the median latency observed, as well as the 90-th, 95-th, and 99-th percentiles (a 99-th percentile of latency of 50 milliseconds, for example, means that 99% of the elements arrive at the end of the pipeline in less than 50 milliseconds).