prometheus-emitter (contrib-extension) - Allow custom bucket ranges for Timer type metrics #17684
Description
In the prometheus-emitter module, Metrics.java creates Timer type metrics with hard coded bucket boundaries. These boundaries make sense for some metrics, but not all. For instance, batch ingestion job times for hadoop ingest are rarely < 5 min at my shop, leading them to be categorized in the inf+ bucket which is not useful for reporting.
I think it will be fairly straightforward to allow the metrics config to override bucket boundaries, or else use these current defaults.
I hope to raise a PR to fix in the near term, but don't have immediate capacity so I am throwing up an issue in the event that someone feels the urge to grab it before me.
code snippet from the aforementioned Metrics.java class
...
} else if (Metric.Type.timer.equals(type)) {
collector = new Histogram.Builder()
.namespace(namespace)
.name(formattedName)
.labelNames(dimensions)
.buckets(.1, .25, .5, .75, 1, 2.5, 5, 7.5, 10, 30, 60, 120, 300) // These are the static bucket ranges
.help(metric.help)
.register();
}
...