Why can't I increase session.timeout.ms?

These conditions needed to be keep in mind to change session.timeout.ms:

1. group.max.session.timeout.ms in the server.properties > session.timeout.ms in the consumer.properties.
2. group.min.session.timeout.ms in the server.properties < session.timeout.ms in the consumer.properties.
3. request.timeout.ms > session.timeout.ms + fetch.wait.max.ms
4. (session.timeout.ms)/3 > heartbeat.interval.ms
5. session.timeout.ms > Worst case processing time of Consumer Records per consumer poll(ms).

The range of consumer session timeout is controlled by broker group.max.session.timeout.ms(default 30s) and group.min.session.timeout.ms(default 6s).

You should increase group.max.session.timeout.ms first in broker side, otherwise you will get "The session timeout is not within an acceptable range.".