title: What does it mean for TCP connections to churn?
body: <p>In the context of webservices, I've seen the term "TCP connection churn" used. Specifically <a href="http://engineering.twitter.com/2011/08/finagle-protocol-agnostic-rpc-system.html" rel="noreferrer">Twitter finagle</a> has ways to avoid it happening. How does it happen? What does it mean?</p>