Identifying Performance Bottlenecks in CDNs Through TCP-Level Monitoring
Content Distribution Networks (CDNs) need to make decisions, such as server selection and routing, to improve performance for their clients. The performance may be limited by various factors such as packet loss in the network, a small receive buffer at the client, or constrained server CPU and disk resources. Conventional measurement techniques are not effective for distinguishing these performance problems: application-layer logs are too coarse-grained, while network-level traces are too expensive to collect all the time. The authors argue that passively monitoring the transport-level statistics in the server's network stack is a better approach.