Dash0 provides synthetic metrics to help you analyze logs, spans, and related telemetry data dynamically without requiring predefined metric aggregations.

Synthetic metrics are calculated on-the-fly from other telemetry ingested by Dash0. They can query only data that exists within your organization's retention period and are not charged on your bill.

Key Use Cases

Count and alert on logs, spans, span events, metric data points, and resources dynamically.
Avoid upfront metric definitions, making observability more flexible.
No additional charges on telemetry already sent to Dash0.
Enable advanced query-building for performance monitoring, anomaly detection, and billing analysis.

Retention and Availability

Synthetic metrics rely on retained telemetry:

Logs, spans, and span events: 30-day retention period.
Metric data points: 13-month retention period.

Cost

Synthetic metrics do not incur extra costs. You already pay for them by ingesting the raw telemetry (spans, span events, log records, metric data points) they are computed from.

Querying Synthetic Metrics

Synthetic metrics do not carry pre-computed attribute dimensions. Instead, attributes are materialised on query by grouping in PromQL:

promql

1
sum by (service_name) ({otel_metric_name="dash0.spans"})

This yields one time series per distinct value of service.name.

Available attributes

Two categories of attributes are available for grouping, depending on the metric:

Resource attributes — attributes set at the resource level (e.g. service.name, service.version, k8s.namespace.name, k8s.deployment.name, cloud.provider). These are available on metrics derived from logs, spans, metric data points, and Gen AI signals. They are not available on synthetic check metrics (dash0.synthetic_check.*) or web metrics (dash0.web.*).

Signal attributes — attributes set at the individual signal level, specific to each metric type:

Logs (dash0.logs): otel.log.severity.range, otel.log.severity.text, otel.event.name, dash0.log.pattern, and others from the Log Attributes registry.
Spans (dash0.spans, dash0.spans.duration, dash0.spans.red): dash0.operation.name, dash0.operation.type, otel.span.kind, otel.span.status.code, http.response.status_code, http.route, and others from the Span Attributes registry.
Span events (dash0.span.events): all span attributes above, plus otel.span.event.name.
Metric data points (dash0.metrics.datapoints): otel.metric.name, otel.metric.type, otel.metric.unit, otel.scope.name.
Resources (dash0.resources): dash0.resource.id, dash0.resource.name, dash0.resource.type, plus any resource attribute.
Synthetic checks (dash0.synthetic_check.*): dash0.check.id, dash0.check.name, dash0.check.type, dash0.synthetic_check.location, dash0.synthetic_check.outcome, http.response.status_code.
Web (dash0.web.*): page.url.path, page.url.domain, user_agent.name, user_agent.os.name, geo.country_iso_code, session.id, and many others from the Web Event Attributes registry.
Gen AI (dash0.gen_ai.*): gen_ai.operation.name, gen_ai.conversation.id, plus all span attributes.

Synthetic Metric Reference

Namespace	Metric	Instrument	Unit
Gen AI	dash0.gen_ai.cache_tokens.input	Counter	`{token}`
	dash0.gen_ai.cache_tokens.output	Counter	`{token}`
	dash0.gen_ai.chats	Counter	`{chat}`
	dash0.gen_ai.chats.duration	Histogram	`s`
	dash0.gen_ai.conversations	Counter	`{conversation}`
	dash0.gen_ai.conversations.duration	Histogram	`s`
	dash0.gen_ai.conversations.info	Gauge	`1`
	dash0.gen_ai.subagents	Counter	`{subagent}`
	dash0.gen_ai.subagents.duration	Histogram	`s`
	dash0.gen_ai.tokens.input	Counter	`{token}`
	dash0.gen_ai.tokens.output	Counter	`{token}`
	dash0.gen_ai.tool_calls	Counter	`{tool_call}`
	dash0.gen_ai.tool_calls.duration	Histogram	`s`
	dash0.gen_ai.usage.cost	Counter	`USD`
Logs	dash0.logs	Counter	`{log}`
Metrics	dash0.metrics.datapoints	Counter	`{metric_datapoint}`
Resources	dash0.resources	Gauge	`{resource}`
Span	dash0.span.events	Counter	`{span_event}`
Spans	dash0.spans	Counter	`{span}`
	dash0.spans.duration	Histogram	`s`
Synthetic Check	dash0.synthetic_check.http.connection.duration	Histogram	`s`
	dash0.synthetic_check.http.dns.duration	Histogram	`s`
	dash0.synthetic_check.http.request.duration	Histogram	`s`
	dash0.synthetic_check.http.response.duration	Histogram	`s`
	dash0.synthetic_check.http.ssl.duration	Histogram	`s`
	dash0.synthetic_check.http.total.duration	Histogram	`s`
	dash0.synthetic_check.runs	Counter	`{run}`
Web	dash0.web.bounces	Counter	`{bounce}`
	dash0.web.errors	Counter	`{error}`
	dash0.web.events	Counter	`{web_event}`
	dash0.web.page_views	Counter	`{page_view}`
	dash0.web.requests	Counter	`{request}`
	dash0.web.requests.duration	Histogram	`s`
	dash0.web.sessions	Counter	`{session}`
	dash0.web.sessions.duration	Histogram	`s`
	dash0.web.users	Counter	`{user}`
	dash0.web.vitals.cls	Histogram	`1`
	dash0.web.vitals.inp	Histogram	`s`
	dash0.web.vitals.lcp	Histogram	`s`