Functional and Performance testing on applications built on kafka, elastic search and kibana

I am working on a system where stream of data(real time data) is pushed to kafka cluster and then to elastic search and displayed through kibana.

Do i need to testing on the kafka cluster, testing on elastic search cluster separately?. I am confused how to go with exact testing approach for this.

Could someone help me to do testing approach for functional and performance testing on the applications built on this stack and are there are any tools that helps to do.

Thanks in Advance.