Imagine a live streaming viewer wants to know the delay of their live video, or a live infrastructure engineer wants to capture the latency performance of the pipeline, how could you have the latency systematically measured nearline at scale?

In this talk, we will present a latency measurement framework we developed for Linkedin live video. It supports capturing per stream latency from ingestion to playback, leveraging technologies including media signaling, header manipulation, and streaming processing. We’ll be covering four major latency contributing factors in the live pipeline: ingestion to storage, origin server processing, origin to CDN, and CDN to client player latency. We will discuss how we work across the stack with Azure Media Service to capture each latency component per client in nearline fashion. We’ll also share some “glitches” we caught while building the flow. Presented at Demuxed 2021.