Specificationv1.61.0

14 Sept 2026since v1.60.0

5 breaking24 notable30 editorial

From the upstream release notes

Recommend instead of require global propagators.
Add view_matching_mode parameter to MeterProvider to support composable View matching.
Clarify maxExportBatchSize behavior, timeouts, and error handling for
Mark maxExportBatchSize on Periodic exporting MetricReader as stable.
Allow the named service resource detector (used via declarative config or explicit detector configuration) to fall back to
Add AttributeValueDepthLimit for nested array and map attribute values.
Remove requirement for attribute ordering from compliance matrix.
Stabilize content negotiation section for the Prometheus exporter.
Update the OpenTelemetry Exponential Histogram to Prometheus Native Histogram
Stabilize resource_constant_labels configuration for the Prometheus exporter.

Read the full release notes

Breaking5

Requirements added to, removed from, or restrengthened in a document marked Stable.

strengthrequirementcontext/api-propagators.md#get-global-propagatorMUST relaxed to SHOULD: This method SHOULD exist for each supported Propagator type.
strengthrequirementcontext/api-propagators.md#set-global-propagatorMUST relaxed to SHOULD: This method SHOULD exist for each supported Propagator type.
new rulerequirementcommon/README.md#attribute-limitsMUST added: the SDK MUST start counting depth at 1 for the top-level attribute value, and increment depth when descending into arrays (both homogeneous and heterogeneous) or maps;
new rulerequirementcommon/README.md#attribute-limitsMUST added: arrays or map at a depth greater than the limit MUST be replaced with an empty value;
new rulerequirementcommon/README.md#attribute-limitsMUST NOT added: otherwise a value MUST NOT be changed due to the depth limit.

Notable24

rule droppedrequirementspecification/document-status.md#maturity-levelsMUST removed: They also MUST communicate in which version they will be removed. | | Unmaintained | A component identified as unmaintained does not have an active code owner.
strengthrequirementsdk_exporters/prometheus.md#resource-attributes-as-metric-labelsSHOULD relaxed to MAY: The option MAY be named resourceconstant_labels.
strengthrequirementmetrics/sdk.md#forceflush-1SHOULD relaxed to MAY: Language implementations MAY decide how to model ERROR and NO ERROR.
new rulerequirementcompatibility/prometheus_and_openmetrics.md#exponential-histogramsMUST added: The flavor of the Native Histogram MUST be of the integer and counter flavor.
new rulerequirementcompatibility/prometheus_and_openmetrics.md#exponential-histogramsMUST added: The ResetHint (or CounterResetHint) in the Native Histogram MUST be set to UNKNOWN.
new rulerequirementcompatibility/prometheus_and_openmetrics.md#exponential-histogramsMUST added: If Scale is < -4, the data point MUST be dropped.
new rulerequirementcompatibility/prometheus_and_openmetrics.md#exponential-histogramsMUST added: All fields of the Native Histogram that are not explicitly referenced here MUST be set to their zero value, such as custom values.
new rulerequirementcompatibility/prometheus_and_openmetrics.md#exponential-histogramsMUST added: If the NoRecordedValue flag is set to true, the Native Histogram MUST be marked as stale:
new rulerequirementcompatibility/prometheus_and_openmetrics.md#exponential-histogramsMUST added: The Native Histogram Sum MUST be set to the Stale NaN value.
new rulerequirementcompatibility/prometheus_and_openmetrics.md#exponential-histogramsMUST added: The Native Histogram Count MUST be set to zero.
new rulerequirementcompatibility/prometheus_and_openmetrics.md#exponential-histogramsMUST added: ZeroCount, PositiveSpans, PositiveDeltas, NegativeSpans, and NegativeDeltas MUST be left empty.
new rulerequirementcompatibility/prometheus_and_openmetrics.md#exponential-histogramsMUST added: Sum, if set, is converted to the Native Histogram Sum; otherwise, the metric point MUST be dropped.
new rulerequirementcompatibility/prometheus_and_openmetrics.md#exponential-histogramsMUST added: Non-zero bucket counts MUST be converted into PositiveDeltas (or NegativeDeltas).
new rulerequirementcompatibility/prometheus_and_openmetrics.md#exponential-histogramsMUST added: OpenTelemetry Exponential Histograms with a delta aggregation temporality MAY be aggregated into a cumulative aggregation temporality and follow the logic above, or MUST be dropped.
new rulerequirementspecification/maturity-levels.md#deprecatedMUST added: They also MUST communicate in which version they will be removed, either in terms of a concrete version number or the date of a release, like: "the first release after 2023-08-01".
new rulerequirementspecification/maturity-levels.md#maturity-levelsMUST added: Deliverables of a SIG MUST have a declared maturity level, established by SIG maintainers, likely with the input of the code owners.
new rulerequirementsdk_exporters/prometheus.md#content-negotiationMUST added: If no Accept header is provided and no fallback protocol is configured, the exporter MUST use Prometheus text format 0.0.4 (text/plain; version=0.0.4) and apply underscores escaping.
new rulerequirementmetrics/sdk.md#measurement-processingMUST added: If both the matching Views and Instrument advisory parameters specify the same aspect of the Stream configuration, the setting defined by the Views MUST take precedence over the advisory parameters.
new rulerequirementmetrics/sdk.md#periodic-exporting-metricreaderMUST added: If an export is still in progress when the next scheduled interval occurs, the reader MUST either delay the subsequent collection and export until the in-progress export finishes, or skip the scheduled collection for th...
new rulerequirementmetrics/sdk.md#view-matching-modeMUST added: A MeterProvider that accepts this parameter MUST support the following values:
new rulerequirementmetrics/sdk.md#view-matching-modeMUST added: If viewmatchingmode is not specified, the SDK MUST use independent.
new rulerequirementmetrics/sdk.md#view-matching-modeMUST added: Any other value MUST be treated as unsupported.
new rulerequirementmetrics/sdk.md#view-matching-modeMUST added: If an unsupported value is provided, the SDK MUST either fail fast during initialization in accordance with the error handling principles, or emit a warning, ignore the value, and use independent.
new rulerequirementresource/sdk.md#resource-detector-nameSHOULD added: service: Populates service.name from the OTELSERVICENAME environment variable and SHOULD fall back to language- or platform-specific sources (for example spring.application.name, a JAR manifest, or a Composer/pack...

Editorial30

rule droppedrequirementspecification/document-status.md#maturity-levelsSHOULD NOT removed: The component SHOULD NOT be used in production.
rule droppedrequirementspecification/document-status.md#maturity-levelsMAY removed: The component MAY be removed without prior notice. | | Alpha | The component is ready to be used for limited non-critical production workloads, and the authors of this component welcome user feedback.
rule droppedrequirementspecification/document-status.md#maturity-levelsSHOULD removed: Issues and pull requests for unmaintained components SHOULD be labeled as such.
rule droppedrequirementspecification/document-status.md#maturity-levelsMAY removed: After 6 months of being unmaintained, these components MAY be deprecated.
new rulerequirementcompatibility/prometheus_and_openmetrics.md#exponential-histogramsSHOULD added: If set, StartTimeUnixNano SHOULD be transformed into Prometheus StartTime, following the appropriate format used by each Prometheus protocol.
new rulerequirementcompatibility/prometheus_and_openmetrics.md#exponential-histogramsMAY added: Zero-count buckets MAY also be included to extend an enclosing span (rather than creating a gap between spans) and reduce the number of PositiveSpans (or NegativeSpans).
new rulerequirementspecification/maturity-levels.md#developmentSHOULD NOT added: The component SHOULD NOT be used in production.
new rulerequirementspecification/maturity-levels.md#developmentMAY added: The component MAY be removed without prior notice.
new rulerequirementspecification/maturity-levels.md#maturity-levelsSHOULD NOT added: Components SHOULD NOT be marked as [Stable][] if their user-visible interfaces are not [Stable][].
new rulerequirementspecification/maturity-levels.md#unmaintainedSHOULD added: Issues and pull requests for Unmaintained components SHOULD be labeled as such.
new rulerequirementspecification/maturity-levels.md#unmaintainedMAY added: After 6 months of being Unmaintained, these components MAY be [Deprecated][].
new rulerequirementmetrics/sdk.md#forceflush-1SHOULD added: If any Export(batch) call fails or times out, or if the configured exporter's ForceFlush() fails or times out, ForceFlush SHOULD return some ERROR status.
new rulerequirementmetrics/sdk.md#forceflush-1SHOULD added: If all calls succeed, ForceFlush SHOULD return some NO ERROR status.
new rulerequirementmetrics/sdk.md#measurement-processingSHOULD added: If applying the View would produce semantic errors (for example, configuring an asynchronous instrument to use the Explicit bucket histogram aggregation), the implementation SHOULD emit a warning and proceed as if that ...
new rulerequirementmetrics/sdk.md#measurement-processingSHOULD added: If a setting selected for the stream would produce semantic errors, the implementation SHOULD emit a warning and use the next valid setting for that aspect from a preceding View in the same group, or the Instrument defa...
new rulerequirementmetrics/sdk.md#view-matching-modeMAY added: A MeterProvider MAY accept a viewmatchingmode parameter which controls how multiple matching Views are applied to an Instrument.
rewordedrequirementcommon/README.md#attribute-limitsMAY reworded: There MAY be a log emitted to indicate to the user that an attribute was truncated, discarded, or replaced due to a limit.
rewordedrequirementcompatibility/prometheus_and_openmetrics.md#exponential-histogramsMUST reworded: An OpenTelemetry Exponential Histogram with a cumulative aggregation temporality MUST be converted to a Prometheus Native Histogram with standard (exponential) schema as follows:
rewordedrequirementcompatibility/prometheus_and_openmetrics.md#exponential-histogramsSHOULD reworded: If Scale is > 8 then Exponential Histogram data points SHOULD be downscaled to a scale accepted by Prometheus.
rewordedrequirementmetrics/sdk.md#configurationMUST reworded: Configuration ( i.e. MetricExporters, MetricReaders, Views, and (Development) MeterConfigurator and (Development) viewmatchingmode) MUST be owned by the MeterProvider.
rewordedrequirementmetrics/sdk.md#forceflush-1SHOULD reworded: ForceFlush SHOULD collect metrics, split into batches if necessary, call Export(batch) on each batch serially, and call ForceFlush() on the configured Push Metric Exporter.
rewordedrequirementmetrics/sdk.md#measurement-processingMUST reworded: If both the View and Instrument advisory parameters specify the same aspect of the Stream configuration, the setting defined by the View MUST take precedence over the advisory parameters.
rewordedrequirementmetrics/sdk.md#periodic-exporting-metricreaderMUST reworded: When maxExportBatchSize is configured, the reader MUST ensure no batch provided to Export exceeds the maxExportBatchSize by splitting the batch of metric data points into smaller batches.
rewordedrequirementmetrics/sdk.md#periodic-exporting-metricreaderMUST reworded: The reader MUST ensure all batches produced from a single Collect() are provided to Export serially and in-order before metric data points from a subsequent Collect() are provided.
rewordedrequirementresource/sdk.md#mergeMUST reworded: If either resource contains Entities then merge behavior with Entities MUST be used, otherwise merge behavior without Entities MUST be used.
addeddocumentspecification/maturity-levels.mdNew document: Maturity levels (Unspecified).
addedsectionmetrics/sdk.md#view-matching-modeNew section "View matching mode".
rewrittensectioncompatibility/prometheus_and_openmetrics.md#exponential-histograms"Exponential Histograms" substantially rewritten (2189 to 4940 characters).
rewrittensectionspecification/document-status.md#maturity-levels"Maturity levels" substantially rewritten (3838 to 116 characters).
rewrittensectionmetrics/sdk.md#measurement-processing"Measurement processing" substantially rewritten (2179 to 4308 characters).