MetricDigest

The value-version this producer last delivered for each metric series.

Metrics differ from spans and logs: a series' value moves (a MetricKind.SUM climbs, a MetricKind.GAUGE overwrites), so identity (MetricKey) is not enough — the digest also carries a hash of the last-delivered value (MetricPoint.valueHash). A series is re-sent only when its current value-hash differs from versions.

Producer-local, same as LogDigest and SpanDigest: it records what this producer has already delivered to this endpoint, not what the collector holds.

Parameters