In this chapter, we covered the essential mechanisms to troubleshoot the problems that may occur as part of a RabbitMQ instance. We discussed a general approach towards troubleshooting, along with an overview of some common problems that may occur during startup or shutdown of the message broker. For more detailed troublshooting, we introduced the fundamentals of the Erlang programming language and we will reuse that knowledge when we discuss how to extend RabbitMQ. In the next chapter, we will further expand on the concepts that are covered in this chapter by discussing how to troubleshoot security-related issues.