While trying to add a cassandra monitor, why am i getting "Unable to connect to the host / port" error message?

While trying to add a cassandra monitor, why am i getting "Unable to connect to the host / port" error message?

Solution:
Applications Manager connects to Apache Cassandra via JMX. The "Unable to connect" error typically indicates that the Cassandra JMX port (default: 7199) is unreachable from the Applications Manager server, is bound incorrectly, or requires specific JVM configurations.
  • Check Connectivity: Verify that the Cassandra host and JMX port are accessible from the server where Applications Manager is installed. You can find the configured JMX port in the [CASSANDRA_HOME]/conf/cassandra-env.sh (Linux) or cassandra-env.ps1 (Windows) file.
  • Enable Remote JMX: By default, Cassandra make JMX connections accessible only from localhost. To allow Applications Manager to connect remotely, change the LOCAL_JMX setting to no in cassandra-env.sh or cassandra-env.ps1 file. Refer to Apache Cassandra security and configuration for the same.
  • Authentication Settings: If Cassandra JMX authenticated is enabled, enable the "Is Authentication Required" option in Applications Manager. Ensure that the credentials provided match the user in your jmxremote.password file.