Key metric types

The key types involved in tracing are:

• Metric: A kind of event representing a metric sample.
• Source: A producer of metric events that can be sampled.
• Reporter: A set of Sources that are sampled together. A Reporter will normalize timestamps on metric events so they line up. See Reporting sources for more details.
• Sampler: A receiver of metric events. A Sampler will typically forward on to an Emitter.
• Delta: A utility for simplifying the construction of metric events that report deltas instead of cumulative values. See Delta metrics for more details.
• Distribution: A utility for simplifying the construction of exponential histograms. See Diatributions for more details.