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Status

Current state: "Under Discussion" Accepted (1.0.0)

Discussion thread: here [Change the link from the KIP proposal email archive to your own email thread]

JIRA: KAFKA-5738

Please keep the discussion on the mailing list rather than commenting on the wiki (wiki discussions get unwieldy fast).

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Proposed Changes

A new Stat named org.apache.kafka.common.metrics.stats.RateMeter will be added which will be converted to a CompoundStat similar to Percentiles, with two metrics: rate and total (e.g. request-rate and request-total). For consistency, metrics like io-wait-ratio which specify time ratio will also have two attributes (e.g. io-wait-ratio and io-wait-time-total).

Example:

rateMetricName = metrics.metricName("request-rate", metricGrpName, "The average number of requests sent per second.", metricTags);
totalMetricName = metrics.metricName("request-total", metricGrpName, "The total number of requests sent.", metricTags);
this.bytesSent.add(new Meter(new Count(), rateMetricName, totalMetricName));

Meter would be a CompoundStat that returns both total and the existing rate metrics. This is already handled correctly to support Percentiles. The two metrics appear as two Attributes.

 @Override
 public List<NamedMeasurable> stats() {
    List<NamedMeasurable> stats = new ArrayList<NamedMeasurable>(2);
    stats.add(new NamedMeasurable(totalMetricName, total));
    stats.add(new NamedMeasurable(rateMetricName, rate));
    return stats;
}

Compatibility, Deprecation, and Migration Plan

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