Database performance testing is an important aspect of JMeter. Not only it offers for RDBMS performance testing but also no sql database like MongoDB.
We have added a JMeter test plan jmx file and other dependent files like database dump in the following git repository.
https://github.com/linuxamination/jmeter-mongodb
Here is the complete tutorial of the process. Follow the steps and you will be able to perform MongoDB Load Testing on your own.