In this recipe, we will learn some performance tuning configurations that may help to squeeze out the last bit of performance from the available hardware. Before diving into performance tuning, we need to evaluate our servers and set a benchmark which can be used to measure improvements after any changes. We will be using a well known HTTP benchmarking tool, Apache Bench (ab). Various other benchmarking tools are available and each one has its own feature set. You can choose the one that best suits your needs.
You will need two systems: one with the web server software installed and another to run Apache Bench. You will need root access or access to an account with similar privileges.
You will also need to modify a few network parameters to handle a large network load. You will also need to set a higher open files limit, in limits.conf, on both systems. Check the Tuning TCP Stack recipe in Chapter 2, Networking.