In this chapter, we explored the OpenStack projects at a high level. You learned a little about each of the core projects and some of the optional projects that are deployed. We looked at the main supporting technologies that OpenStack leverages to provide things like, data persistence, and messaging. Finally, we introduced the troubleshooting methodology that we will use throughout this book and a few of the troubleshooting tools that we will take advantage of while working with OpenStack. In the next chapter, we will dive into troubleshooting OpenStack Keystone, the identity service.