Best-Effort Scan of Twitch's CDN in Europe
Journal
ACM International Conference Proceeding Series
ISBN
9798400709395
Date Issued
2023-12-12
Author(s)
Abstract
Twitch is a live video service that is a leader in game streaming with 20 billion annual viewing hours and an annual viewer growth rate of +26%. To sustain this load and growth rate, Twitch maintains a content distribution network (CDN) to ensure high service quality and to distribute load. Its CDN is a critical online infrastructure that should be better understood. To supplement recent works attempting to measure Twitch's CDN that crawled few active channels (~2%) and focused on mapping the CDN, we aimed to (1) scan the channels as complete as possible, which we refer to as a best-effort scan and (2) infer the server allocation scheme behind. To contain the crawling traffic, we scope the scan within Europe. We observed 1045 servers in 24 server clusters which are located in 17 cities across 13 countries in Europe. We found that Twitch's server allocation scheme has two phases: In the first phase, a viewer's location (i.e., a vantage point or VP) is determined from their IP prefix and a pool of nearby server cluster(s) is selected. In the second phase, when a new channel is requested, a server cluster is selected and a server in the cluster is randomly selected to handle the load.
Subjects
CDN Mapping | Measurement Tool | Server Allocation | Twitch
Type
conference paper