I have Kafka cluster wkth 3 server and 3 broker each. I already able to monitor 1 broker using jmx. But I noticed data tranfered by jmx is only related to specified broker to which we connect.
How can I monitor "cluster"in general (e.g. I want to know a messages-in-throughput of a topic)?
A single brokers JMX data won't know about other brokers. You'd have to install metrics collectors on each server and aggregate the data into a metrics database.
Prometheus + JMX exporter + Grafana is a popular combination. Then PromQL would be responsible for querying data over each host.