Server tuning refers to the art of adjusting server, JVM, and system configuration to meet the service level performance requirements of directory clients. In the optimal case you achieve service level performance requirements without much tuning at all, perhaps only setting JVM runtime options when installing OpenDJ. If you are reading this chapter, however, you are probably not facing an optimal situation. Instead you are looking for trade offs that maximize performance for clients given the constraints of your deployment. This chapter therefore aims to provide suggestions on how to measure and to improve directory service performance for better trade offs.