Bart Oles - Severalnines AB Database performance affects organizational performance, and we tend to look for quick fixes when under stress. But how can we better understand our database workload and factors that may cause harm to it? What are the limitations in MongoDB that could potentially impact cluster performance? In this talk, we will show you how to identify the factors that limit database performance. We will start with the free MongoDB Cloud monitoring tools. Then we will move on to log files and queries. To be able to achieve optimal use of hardware resources, we will take a look into kernel optimization and other crucial OS settings. Finally, we will look into how to examine performance of MongoDB replication.