Upgrade note for cumulative count metric
Author: Rajini Sivaram
Reviewers: Ismael Juma
Closes from rajinisivaram/MINOR-upgrade-KIP-187
will return <code>0.0</code> in such cases to minimise the probability of breaking users who read the value of every client
metric (via a <code>MetricsReporter</code> implementation or by calling the <code>metrics()</code> method).
<code>org.apache.kafka.common.Metric#metricValue()</code> can be used to retrieve numeric and non-numeric metric values.</li>
+ <li>Every Kafka rate metric now has a corresponding cumulative count metric with the suffix <code>-total</code>
+ to simplify downstream processing. For example, <code>records-consumed-rate</code> has a corresponding
+ metric named <code>records-consumed-total</code>.</li>
<li>Mx4j will only be enabled if the system property <code>kafka_mx4jenable</code> is set to <code>true</code>. Due to a logic
inversion bug, it was previously enabled by default and disabled if <code>kafka_mx4jenable</code> was set to <code>true</code>.</li>
</ul>
