MINOR: Add security considerations for remote JMX in Kafka docs
Reviewers: Manikumar Reddy
<code>records-consumed-rate</code> has a corresponding metric named <code>records-consumed-total</code>.
<p>
The easiest way to see the available metrics is to fire up jconsole and point it at a running kafka client or server; this will allow browsing all metrics with JMX.
+
+ <h4><a id="remote_jmx" href="#remote_jmx">Security Considerations for Remote Monitoring using JMX</a></h4>
+ Apache Kafka disables remote JMX by default. You can enable remote monitoring using JMX by setting the environment variable
+ <code>JMX_PORT</code> for processes started using the CLI or standard Java system properties to enable remote JMX programmatically.
+ You must enable security when enabling remote JMX in production scenarios to ensure that unauthorized users cannot monitor or
+ control your broker or application as well as the platform on which these are running. Note that authentication is disabled for
+ JMX by default in Kafka and security configs must be overridden for production deployments by setting the environment variable
+ <code>KAFKA_JMX_OPTS</code> for processes started using the CLI or by setting appropriate Java system properties. See
+ <a href=https://docs.oracle.com/javase/8/docs/technotes/guides/management/agent.html">Monitoring and Management Using JMX Technology</a>
+ for details on securing JMX.
<p>
We do graphing and alerting on the following metrics:
<table class="data-table">
