Is there any way to change the aggregation temporality according to the metric name (or other label)?

[huange7]

When I set 'otel.exporter.otlp.metrics.temporality.preference=delta', the aggregation temporality is set according to the instrument type. I want to manually specify it according to the metric name or when creating a new metric. Is this allowed?

Any reply is appreciated. Thank you.

[jack-berg]

No there is not. In old old prototypes, the aggregation temporality was configurable at the instrument level, and you could use views to configure it for a single instrument. This feature was pulled before the stable release because we realized that the temporality requirement is really a property of the backend you're sending data to. I.e. backend A supports cumulative, backend B supports delta, backend C supports either. And so we adjusted the design to allow each MetricReader (and associated MetricExporter by extension) to specify the aggregation temporality they require as a function of instrument kind.

MetricExporter extends AggregationTemporalitySelector. To specify a aggergation temporality preference, MetricExporter implementations implement AggregationTemporalitySelector#getAggregationTemporality(InstrumentTYpe).

For the generic OTLP metric exporters, the temporality selector is configurable here: https://github.com/open-telemetry/opentelemetry-java/blob/main/exporters/otlp/all/src/main/java/io/opentelemetry/exporter/otlp/http/metrics/OtlpHttpMetricExporterBuilder.java#L193-L198

[huange7]

Hi, jack. So, an exporter can only support one kind of aggregation temporality, right?

[jack-berg]

One aggregation temporality for each instrument type. For example, you could select delta histograms, and cumulative for all others instrument types.