Dynamic config reloading

In large, high-scale systems where it's critical to minimize downtime, changes requiring a restart of services require careful planning. If you have a Software as a Service (SaaS) style platform, having a delay before deploying changes or new customer signups could be quite detrimental to your operations.

System downtime can also be required in load balancing situations, where you need to add and remove application backends on the fly. Thankfully, NGINX Plus allows for the configuration to be reloaded without having to restart the services. In this recipe, we'll go through how to update your configuration with a dynamic reload.

Getting ready

We're using a basic recipe based on our load balancing recipe back in Chapter 8,Load Balancing. With the open source version of NGINX, adding or removing backend servers from an NGINX configuration required a full reload in order to use the new changes. While this only has a minimal impact on lightly loaded systems, this can be...