Monitoring Types

This section describes the data types used in monitoring:

Counter

Cumulative metric for a numerical value that only increases.

Gauge

Metric for a numerical value that can increase or decrease.

Summary

Metric that samples observations, providing a count of observations, sum total of observed amounts, average rate of events, and moving average rates across a sliding time window.

The Prometheus view does not provide time-based statistics, as rates can be calculated from the time-series data. Instead, the Prometheus view includes summary metrics whose names have the following suffixes or labels:

  • _count: number of events recorded

  • _total: sum of the amounts of events recorded

  • {quantile="0.5"}: 50% at or below this value

  • {quantile="0.75"}: 75% at or below this value

  • {quantile="0.95"}: 95% at or below this value

  • {quantile="0.98"}: 98% at or below this value

  • {quantile="0.99"}: 99% at or below this value

  • {quantile="0.999"}: 99.9% at or below this value

Timer

Metric combining time-series summary statistics.

Common REST views show summaries as JSON objects. JSON summaries have the following fields:

{
 "count": number,           // events recorded for this metric
 "max": number,             // maximum duration recorded
 "mean": number,            // total/count, or 0 if count is 0
 "min": number,             // minimum duration recorded for this metric
 "mean_rate": number,       // average rate
 "p50": number,             // 50% at or below this value
 "p75": number,             // 75% at or below this value
 "p95": number,             // 95% at or below this value
 "p98": number,             // 98% at or below this value
 "p99": number,             // 99% at or below this value
 "p999": number,            // 99.9% at or below this value
 "stddev": number,          // standard deviation of recorded durations
 "m15_rate": number,        // fifteen-minute average rate
 "m5_rate": number,         // five-minute average rate
 "m1_rate": number,         // one-minute average rate
 "duration_units": string,  // time unit used in durations
 "rate_units": string,      // event count unit and time unit used in rate
 "total": number            // sum of the durations of events recorded
}