Port Exhaustion, Context Switching, and Why "HttpClientFactory" Exists (.NET)

Hello there!👋🧔‍♂️ When .NET apps call other HTTP APIs under load, production often teaches the same lesson in two different voices: cryptic socket errors such as “Only one usage of each socket address is normally permitted,” and slowdowns or instability that feel like “the network” but trace back to threads waiting on I/O the expensive way. The first story is mostly connection lifecycle (ports, pooling, TIME_WAIT ). The second is mostly scheduling (blocking async work, thread-pool pressure, co