API Traffic Management 101

Chapter 2. Managing Traffic

In this chapter, we look at how you can model your traffic patterns and how those patterns can help you to focus on what’s important.

The two approaches covered here are controlling external traffic (also known as the North–South model) and optimizing for internal traffic (called the East–West model). Both of these approaches have their place, and most companies need a mix of North–South and East–West configuration and controls in place in order to both protect your network from external problems and support your internal service ecosystem as it grows and changes over time.

The North–South approach is typically associated with traditional monolithic implementations. However, as more and more microservices are entering company IT operations, the North–South model may not always be the best options. Let’s start by exploring the North–South model first, and then we can deal with the alternative.

According to the “Cisco Global Cloud Index” (updated in late 2018), the East–West (server-to-server) traffic was estimated to reach 85% of total datacenter traffic by 2021. The total portion of North–South traffic (traffic exiting the datacenter) is expected to amount to about 15% of the total traffic. Despite this lopsided distribution, North–South traffic has received the bulk of traffic management’s attention in recent years due to the increased vulnerabilities and lack of predictability when dealing with traffic that originates (or terminates) outside your ...