Learn How to Lower Heroku Dyno Latency through Persistent Connections (Keep-alive)

The Performance Penalty of Repeated Connections Before the latest improvements to the Heroku Router, every connection between the router and your application dyno risked incurring the latency penalty of a TCP slow start . To understand why this is a performance bottleneck for modern web applications, we must look at the fundamentals of the Transmission Control Protocol (TCP) and its history with HTTP. Maybe you’ve heard of a keep-alive connection, but haven’t thought much about what it is or w...