Any reason why Polly create histogram metrics with units as milliseconds and type as double?

[lvxiaoxin]

Hi Polly expert:

I noticed that Polly is creating resilience.polly.strategy.attempt.duration and resilience.polly.pipeline.duration with units as ms, histogram type as double. Any reason for that? Per my understanding, usually we would use double when unit is seconds, or use long as type when unit is milliseconds.

[martincostello]

The type is the same as the type of the value we report:

Polly/src/Polly.Extensions/Telemetry/TelemetryListenerImpl.cs

Line 143 in 12fe569

AttemptDuration.Record(executionAttempt.Duration.TotalMilliseconds, tags.TagsSpan);

Duration is a TimeSpan:

Polly/src/Polly.Core/Telemetry/ExecutionAttemptArguments.cs

Lines 31 to 34 in 12fe569

	/// <summary>
	/// Gets the execution duration of the attempt.
	/// </summary>
	public TimeSpan Duration { get; }

TimeSpan.TotalMilliseconds is a double.