No matter how we tune our Docker applications, we will reach our application's performance limits. Using the benchmarking techniques we discussed in the previous chapter, we should be able to identify the capacity of our application. In the near future, our Docker application's users will exceed this limit. We cannot turn these users away just because our Docker application cannot handle their requests anymore. We need to scale out our application so that it can serve our growing number of users.
In this chapter, we will talk about how to scale out our Docker applications to increase our capacity. We will use load balancers, which are a key component in the architecture of various web scale applications. Load balancers distribute our application's users to multiple Docker applications deployed in our farm of Docker hosts. The following steps covered in this chapter will help us to accomplish this:
- Preparing application backends
- Balancing load with NGINX
- Scaling out...