Stop ignoring long measurements in HistogramExemplarReservoir #5216
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As noted by @dashpole here there's a bug in the
HistogramExemplarReservoir
implementation.HistogramPointData only supports double exemplars. Despite our API supporting both
LongHistogram
andDoubleHistogram
, long values are simply converted to doubles in the aggregator. However, theHistogramExemplarReservoir
didn't get the memo and reports a value of0.0
when any long measurement is recorded as an exemplar.This fixes the issue by casting long measurements to double before storing in the reservoir.