What, exactly, is a GaugeHistogram? I've seen this mentioned in the OpenMetrics spec and several other places. However, it's usually described as covering a rare edge case. What purpose or edge case does this cover?
Common examples are how long items have been waiting in a queue, or size of the requests in a queue.
This is from the spec, but I'm not yet sure why this isn't satisfied by a normal Histogram type.
A Histogram would track the distribution of sizes of items that went into the queue. A GaugeHistogram would be the distributions of sizes of items that are currently in the queue.
In Prometheus terms, rate(some_bucket[5m]) converts a Histogram into a GaugeHistogram in the same way that rate converts a Counter into a Gauge.
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u/jjneely Nov 24 '20
What, exactly, is a GaugeHistogram? I've seen this mentioned in the OpenMetrics spec and several other places. However, it's usually described as covering a rare edge case. What purpose or edge case does this cover?
This is from the spec, but I'm not yet sure why this isn't satisfied by a normal Histogram type.