Please update changelog as part of any significant pull request. Place short description of your change into "Unreleased" section. As part of release process content of "Unreleased" section content will generate release notes for the release.
ParentBased
sampler is a decorator (not a composite). (#3706)
- Stabilize
ExplicitBucketBoundaries
instrument advisory parameter. (#3694)
- No changes.
- No changes.
- Increase metric name maximum length from 63 to 255 characters. (#3648)
- MetricReader.Collect ignores Resource from MetricProducer.Produce. (#3636)
- Attribute sets not observed during async callbacks are not exported. (#3242)
- Promote MetricProducer specification to feature-freeze. (#3655)
- Add synchronous gauge instrument, clarify temporality selection influence on metric point persistence. (#3540)
- Clarify that advice is non-identifying. (#3661)
- Define the default size of the
SimpleFixedSizeExemplarReservoir
to be1
. (#3670) - Rename "advice" to "advisory parameters". (#3662)
- Clarify the minimal implementation of a
View
'sattribute_keys
is an allow-list. (#3680) - Add "/" to valid characters for instrument names (#3684)
- Stabilize the
MetricProducer
. (#3685)
- Update GCP data model to use
TraceFlags
instead ofgcp.trace_sampled
. (#3629)
- No changes.
- Fix and clarify definition of "transient error" in the OTLP exporter specification. (#3653)
- OpenTracing Shim: Allow invalid but sampled SpanContext to be returned. (#3471)
- Prometheus: Allow changing metric names by default when translating from Prometheus to OpenTelemetry. (#3679)
- No changes.
- No changes.
- No changes.
- No changes.
- No changes.
- Specify how to handle instrument name conflicts. (#3626)
- Add experimental metric attributes advice API. (#3546)
- Revise the exemplar default reservoirs. (#3627)
- Mark the default aggregation cardinality Experimental in MetricReader. (#3619)
- Mark Metric No-Op API as stable. (#3642)
- MetricProducers are provided as config to MetricReaders instead of through a RegisterProducer operation. (#3613)
- Refine
MetricProvider.ForceFlush
and defineForceFlush
for periodic exporting MetricReader. (#3563)
- Clarify how log appender use Scope name and attributes. (#3583)
- Mark No-Op Logs Bridge API as stable. (#3642)
- No changes.
- Prometheus exporters SHOULD provide configuration to disable the addition of
_total
suffixes. (#3590)
- No changes.
- No changes.
- No changes.
- No changes.
- Refine SDK TracerProvider configuration section. (#3559)
- Make SDK Tracer Creation more normative. (#3529)
- Refine SDK MeterProvider configuration section. (#3522)
- Clarify metric view requirements and recommendations. (#3524)
- Change the view name to be the view's stream configuration name. (#3524)
- Make SDK Meter Creation more normative. (#3529)
- Clarify duplicate instrument registration scope to be a MeterProvider. (#3538)
- Clarify identical instrument definition for SDK. (#3585)
- Refine SDK LoggerProvider configuration section. (#3559)
- Make SDK Logger Creation more normative. (#3529)
- No changes.
- NOTICE: Remove the Jaeger Exporter (#3567)
- Prometheus: Do not add
_total
suffix if the metric already ends in_total
. (#3581) - Prometheus type and unit suffixes are not trimmed by default. (#3580)
- Extract Exemplar section and mark it as Experimental. (#3533)
- No changes.
- No changes.
- No changes.
- No changes.
- Make recommendation to reserve aggregator normative. (#3526)
- No changes.
- No changes.
- No changes.
- Move OTLP specification to github.com/open-telemetry/opentelemetry-proto. (#3454)
- No changes.
- No changes.
- Explain why custom attributes are not recommended to be placed in OTel namespaces. (#3507)
- No changes.
- No changes.
- No changes.
- Add experimental histogram advice API. (#3216)
- Recommended non-prefixed units for metric instrument semantic conventions. (#3312)
- Recommended cardinality limits to protect metrics pipelines against excessive data production from a single instrument. (#2960)
- Specify second unit (
s
) and advice bucket boundaries of[]
forprocess.runtime.jvm.gc.duration
. (#3458) - Add links to the JMX APIs that are the JVM runtime metric sources. (#3463)
- Clarify parameters for emitting a log record. (#3345)
- Drop logger include_trace_context parameter. (#3397)
- Clarify how ObservedTimestamp field is set if unspecified (#3385)
- Mark logs bridge API / SDK as stable. (#3376)
- Mark LogRecord Environment Variables as stable. (#3449)
- The Semantic Conventions have moved to a separate repository github.com/open-telemetry/semantic-conventions. There will be no future semantic conventions release from this repository. (#3489)
- Mark OpenCensus compatibility spec as stable (#3425)
- No changes.
- Lay initial groundwork for file configuration (#3360)
- Move file configuration schema to
opentelemetry-configuration
. (#3412) - Move
sdk-configuration.md
andsdk-environment-variables.md
to/specification/configuration/
. (#3434)
- No changes.
- Add log entries to specification README.md contents. (#3435)
- Add guidance to use service-supported propagation formats as default for AWS SDK client calls. (#3212)
- No changes.
- Clarify required parent information in ReadableSpan. Technically a relaxation, but previously it was easy to overlook certain properties were required. #3257
- Remove underspecified and unused Span decorator from Trace SDK. (#3363)
- Clarify that units should use UCUM case sensitive variant. (#3306)
- Remove No-Op instrument and Meter creation requirements. (#3322)
- Fixed attributes requirement level in semantic conventions for hardware metrics (#3258)
- Update log readme "request context" to "trace context". (#3332)
- Remove log readme document status. (#3334)
- Break out compatibility document on recording trace context in non-OTLP Log Format (#3331)
- Ensure Logs Bridge API doesn't contain SDK implementation details (#3275)
- Add Log Bridge API artifact naming guidance (#3346)
- Add log appender / bridge to glossary. (#3335)
- No changes.
- Clarify that attribute requirement levels apply to the instrumentation library (#3289)
- Fix grammatical number of metric units. (#3298)
- Rename
net.app.protocol.(name|version)
tonet.protocol.(name|version)
(#3272) - Replace
http.flavor
withnet.protocol.(name|version)
(#3272) - Metric requirement levels are now stable (#3271)
- BREAKING: remove
messaging.destination.kind
andmessaging.source.kind
. (#3214, #3348) - Define attributes collected for
cosmosdb
by Cosmos DB SDK (#3097) - Clarify stability requirements of semantic conventions (#3225)
- BREAKING: Change span statuses for gRPC server spans. (#3333)
- Stabilize key components of
service.*
andtelemetry.sdk.*
resource semantic conventions. (#3202) - Fixed attributes requirement level in semantic conventions for hardware metrics (#3258)
- Added AWS S3 semantic conventions. (#3251)
- Fix units in the Kafka metric semantic conventions. (#3300)
- Add Trino to Database specific conventions (#3347)
- Change
db.statement
to only be collected if there is sanitization. (#3127) - BREAKING: Remove
http.status_code
attribute from thehttp.server.active_requests
metric. (#3366) - Mark attribute requirement levels as stable (#3368)
- No changes.
- Declare OTLP stable. (#3274)
- No changes.
- No changes.
- No changes.
- No changes.
- No changes.
- Add unit to View's Instrument selection criteria. (#3184)
- Add metric requirement levels "Required", "Recommended", and "Opt-In". (#3237)
- Rename Logs API to Logs Bridge API to prevent confusion. (#3197)
- Move event language from log README to event-api. (#3252)
- Clarify how to collect
host.id
for non-containerized systems. (#3173)
- Move X-Ray Env Variable propagation to span link instead of parent for AWS Lambda. (#3166)
- Add heroku resource semantic conventions. #3075
- BREAKING: Rename faas.execution to faas.invocation_id (#3209)
- BREAKING: Change faas.max_memory units to Bytes instead of MB (#3209)
- BREAKING: Expand scope of faas.id to cloud.resource_id (#3188)
- Add Connect RPC specific conventions (#3116)
- Rename JVM metric attribute value from
nonheap
tonon_heap
(#3250) - Mark the attribute naming guidelines in the specification as stable. (#3220)
- Mark telemetry schema readme stable. (#3221)
- Remove mention of
net.transport
from HTTP semantic conventions (#3244) - Clarifies that if an HTTP client request is explicitly made to an IP address,
e.g.
http://x.x.x.x:8080
, thennet.peer.name
SHOULD be the IP addressx.x.x.x
(#3276) - Mark
net.sock.host.port
as conditionally required. (#3246) - Rename Optional attribute requirement level to Opt-In. (#3228)
- Rename
http.user_agent
touser_agent.original
. (#3190) - Expand the declaration of
pool.name
. (#3050)
- Update Zipkin remoteEndpoint preferences. (#3087)
- Declare OTLP/JSON Stable. (#2930)
- No changes.
- No changes.
- No changes.
- No changes.
- Clarify guidance regarding excessive logging when attributes are dropped or truncated. (#3151)
- No changes.
- Define BatchLogRecordProcessor default configuration values. (#3002)
- Clarify guidance regarding excessive logging when attributes are dropped or truncated. (#3151)
- No changes.
- Add Cloud Spanner and Microsoft SQL Server Compact to db.system semantic conventions (#3105).
- Enable semantic convention tooling for metrics in spec (#3119)
- Rename google openshift platform attribute from
google_cloud_openshift
togcp_openshift
to match the existingcloud.provider
prefix. (#3095) - Changes http server span names from
{http.route}
to{http.method} {http.route}
(when route is available), and fromHTTP {http.method}
to{http.method}
(when route is not available). Changes http client span names fromHTTP {http.method}
to{http.method}
. (#3165) - Mark
http.server.duration
andhttp.client.duration
metrics as required, and mark all other HTTP metrics as optional. #3158 - Add
net.host.port
tohttp.server.active_requests
metrics attributes. #3158 http.route
SHOULD contain the "application root" if there is one. (#3164)
- Add condition with sum and count for Prometheus summaries (3059).
- Clarify prometheus unit conversions (#3066).
- Define conversion mapping from OTel Exponential Histograms to Prometheus Native Histograms. (#3079)
- Fix Prometheus histogram metric suffixes. Bucket series end in
_bucket
(#3018).
- No changes.
- Add log-specific attribute limit configuration and clarify that general attribute limit configuration also apply to log records (#2861).
- No changes.
- No changes.
- No changes.
- Clarify that the BatchSpanProcessor should export batches when the queue reaches the batch size (#3024)
- Deprecate jaeger exporter, scheduled for spec removal in July 2023. #2858
- Rename built-in ExemplarFilters to AlwaysOn, AlwaysOff and TraceBased. (#2919)
- Add
MaxScale
config option to Exponential Bucket Histogram Aggregation. (#3017) - Rename exponential bucket histogram aggregation to base 2 exponential histogram aggregation. Rename "OTEL_EXPORTER_OTLP_METRICS_DEFAULT_HISTOGRAM_AGGREGATION" value from "exponential_bucket_histogram" to "base2_exponential_bucket_histogram". Mark exponential histogram data model and base2 exponential histogram aggregation as stable. (#3041)
- Clarify usage of log body for structured logs (#3023)
- Move appendices from Data Model to new Data Model Appendix document (#3207)
- No changes.
- Clarify common HTTP attributes apply to both clients and servers (#3044)
- Add
code.lineno
source code attribute (#3029) - Add ClickHouse to db.system semantic conventions (#3011)
- Refactor messaging attributes and per-message attributes in batching scenarios.
(#2957).
BREAKING: rename
messaging.consumer_id
tomessaging.consumer.id
,messaging.destination
tomessaging.destination.name
,messaging.temp_destination
tomessaging.destination.temporary
,messaging.destination_kind
tomessaging.destination.kind
,messaging.message_id
tomessaging.message.id
,messaging.protocol
tonet.app.protocol.name
,messaging.protocol_version
,net.app.protocol.version
,messaging.conversation_id
tomessaging.message.conversation_id
,messaging.message_payload_size_bytes
tomessaging.message.payload_size_bytes
,messaging.message_payload_compressed_size_bytes
tomessaging.message.payload_compressed_size_bytes
,messaging.rabbitmq.routing_key
:messaging.rabbitmq.destination.routing_key
,messaging.kafka.message_key
tomessaging.kafka.message.key
,messaging.kafka.consumer_group
tomessaging.kafka.consumer.group
,messaging.kafka.partition
tomessaging.kafka.destination.partition
,messaging.kafka.tombstone
tomessaging.kafka.message.tombstone
,messaging.rocketmq.message_type
tomessaging.rocketmq.message.type
,messaging.rocketmq.message_tag
tomessaging.rocketmq.message.tag
,messaging.rocketmq.message_keys
tomessaging.rocketmq.message.keys
; Removedmessaging.url
; Renamedsend
operation topublish
; Splitdestination
andsource
namespaces and clarify per-message attributes in batching scenarios.
- Add Tracer.Close() to the OpenTracing Shim layer.
- Add OpenCensus migration guide and add BinaryPropagation as an option to gRPC instrumentation for OpenCensus compatibility (#3015).
- Add table for OTLP/HTTP response code and client retry recommendation (#3028)
- Remove spaces from example exporter User-Agent header to conform to RFC7231 & RFC7230. #3052
- Rename knowns values for "OTEL_METRICS_EXEMPLAR_FILTER" to "always_on", "always_off" and "trace_based". (#2919)
- No changes.
- No changes.
- No changes.
- No changes.
- Define Experimental MetricProducer as a third-party provider of metric data to MetricReaders. (#2951)
- Add OTLP exporter temporality preference named "LowMemory" which configures Synchronous Counter and Histogram instruments to use Delta aggregation temporality, which allows them to shed memory following a cardinality explosion, thus use less memory. (#2961)
- Clarification on what an Event is, and what the event.domain and event.name attributes represent (#2848)
- Move
event.domain
from InstrumentationScope attributes to LogRecord attributes. (#2940) - Split out Event API from Log API (#2941)
- Clarify data modification in
LogRecordProcessor
. (#2969) - Make sure it is very clear we are not building a Logging API. (#2966)
- Extend Cloud Platform Enum with OpenShift entry for all supported cloud providers. (#2985)
- Add
process.runtime.jvm.gc.duration
metric to semantic conventions. (#2903) - Make http.status_code metric attribute an int. (#2943)
- Add IBM Cloud as a cloud provider. (#2965)
- Add semantic conventions for Feature Flags (#2529)
- Rename
rpc.request.metadata.<key>
andrpc.response.metadata.<key>
torpc.grpc.request.metadata.<key>
andrpc.grpc.response.metadata.<key>
(#2981) - List the machine-id as potential source for a unique host.id (#2978)
- Add
messaging.kafka.message.offset
attribute. (#2982) - Update hardware metrics to use
direction
as per general semantic conventions (#2942)
- Add OpenCensus metric bridge specification. (#2979)
- No changes.
- Specify handling of invalid numeric environment variables (#2963)
- No changes.
- No changes.
- No changes.
- Rename
http.retry_count
tohttp.resend_count
and clarify its meaning. (#2743)
- Handle duplicate description comments during Prometheus conversion. (#2890)
- Allow to configure min/max recording in the exponential histogram aggregation. (#2904)
- Add table of instrument additive property (#2906)
- Add
Context
as argument toLogRecordProcessor#onEmit
. (#2927)
- No changes.
- Change to messaging.kafka.max.lag from UpDownCounter to Gauge (and rename it) (#2837)
- Add daemon attribute to jvm threads metric (#2828)
- Add gRPC request and response metadata semantic conventions (#2874)
- Add
process.paging.faults
metric to semantic conventions (#2827) - Define semantic conventions yaml for non-otlp conventions (#2850)
- Add more semantic convetion attributes of Apache RocketMQ (#2881)
- Add
process.runtime.jvm.memory.usage_after_last_gc
metric to semantic conventions. (#2901)
- Specify how Prometheus exporters and receivers handle instrumentation scope. (#2703).
- Clarify that lowerCamelCase field names MUST be used for OTLP/JSON (#2829)
- No changes.
- No changes.
- Clarify that Scope is defined at build time (#2878)
- No changes.
- No changes.
- Changed the default buckets for Explicit Bucket Histogram to better match the official Prometheus clients. (#2770).
- Fix OpenMetrics valid label keys, and specify prometheus conversion for metric name. (#2788)
- Add environment variables for configuring the
BatchLogRecordProcessor
. (#2785) - Fix inconsistencies in log README (#2800).
- Add
browser.mobile
andbrowser.language
resource attributes (#2761)
- Add
process.context_switches
, andprocess.open_file_descriptors
, to the metrics semantic conventions (#2706) - Add exceptions to the logs semantic conventions (#2819)
- Make context propagation requirements explicit for messaging semantic conventions (#2750).
- Update http metrics to use
http.route
instead ofhttp.target
for servers, drophttp.url
for clients (#2818).
- No changes.
- Add user agent to OTLP exporter specification (#2684)
- Prohibit usage of enum value name strings in OTLP/JSON (#2758)
- Clarify that unknown fields must be ignored when receiving OTLP/JSON (#2816)
- Add OTLP exporter user agent to the spec compliance matrix (#2842).
- Add the OTEL_SDK_DISABLED environment variable to the SDK configuration. (2679)
- Add the definition of a Boolean environment variable (#2755).
- No changes.
- No changes.
- No changes.
- Clarify the return of
Export(batch)
in the Batch Span Processor and exporter concurrency (#2452) - Clarify that Context should not be mutable when setting a span (#2637)
- Clarify that
ForceFlush
is a required method onSpanExporter
interface (#2654)
- Add experimental
OTEL_EXPORTER_OTLP_DEFAULT_HISTOGRAM_AGGREGATION
variable for configuring default histogram aggregation of OTLP metric exporter (#2619) - Clarify async instrument callback identity (#2538)
- Prometheus export: Only monotonic sum are counters (with
_total
) (#2644) - [OM/OTLP] Use
_created
for StartTimeUnixNano and vice-versa (#2645) - Prometheus compatibility: use target_info metric instead of "target" info MF (#2701)
- Add optional Zero Threshold for Exponential Histograms to the metrics data model (#2665)
- Change the inclusivity of exponential histogram bounds (#2633)
- Add
process.threads
host metric semantic convention. (#2705).
- Update log SDK to allow log processors to mutate log records (#2681).
- Add experimental Events and Logs API specification (#2676)
- Align log SDK and API component naming (#2768).
- Add the signal-specific OTEL_EXPORTER_OTLP_LOGS_* environment variables (#2782).
- Update the version of the W3C Baggage specification used for
OTEL_RESOURCE_ATTRIBUTES
(#2670)
- Add
net.app.protocol.*
attributes (#2602) - Add network metrics to process semantic conventions (#2556)
- Adopt attribute requirement levels in semantic conventions (#2594)
- Add semantic conventions for GraphQL (#2456)
- Change
cloudevents.event_spec_version
andcloudevents.event_type
level fromrequired
torecommended
(#2618) - Change
faas.document.time
andfaas.time
level fromrequired
torecommended
(#2627) - Add
rpc.grpc.status_code
to RPC metric semantic conventions (#2604) - Add
http.*.*.size
metric semantic conventions for tracking size of requests / responses for http servers / clients (#2588) - BREAKING: rename
net.peer.ip
tonet.sock.peer.addr
,net.host.ip
tonet.sock.host.addr
,net.peer.name
tonet.sock.peer.name
for socket-level instrumentation. Define socket-level attributes and clarify logical peer and host attributes meaning (#2594) - Add semantic conventions for JVM buffer pool usage (#2650)
- Improve the definition of
state
attribute for metricsystem.network.connections
(#2663) - Add
process.parent_pid
attribute for use in reporting parent process id (PID) (#2691) - Add OpenSearch to db.system semantic conventions (#2718)
- Clarify when "count" is used instead of pluralization (#2613)
- Add the convention 'type' to the YAML definitions for all existing semantic conventions (#2693)
- Remove alternative attribute sets from HTTP semantic conventions (#2469)
- No changes.
- Add support for partial success in an OTLP export response (#2696)
- Mark
OTEL_METRIC_EXPORT_INTERVAL
,OTEL_METRIC_EXPORT_TIMEOUT
environment variables as Stable (#2658)
- Introduce "split" metric schema transformation (#2653)
- Introduce Instrumentation Scope Attributes
(#2579)
- Define Instrumentation Scope Attributes as non identifiers (#2789)
- No changes.
- No changes.
- Clarify that API support for multi-instrument callbacks is permitted. (#2263).
- Clarify SDK behavior when view conflicts are present (#2462).
- Clarify MetricReader.Collect result (#2495).
- Specify optional support for an Exponential Histogram Aggregation. (#2252)
- Update Prometheus Sums for handling delta counter case (#2570).
- Supplementary guidance for metrics additive property (#2571).
- OTLP Logs are now Stable (#2565)
- No changes.
- Add semantic conventions for JVM CPU metrics (#2292)
- Add details for FaaS conventions for Azure Functions and allow FaaS/Cloud resources as span attributes on incoming FaaS spans (#2502)
- Define attribute requirement levels (#2522)
- Initial addition of Kafka metrics (#2485).
- Add semantic conventions for Kafka consumer metrics (#2536)
- Add database connection pool metrics semantic conventions (#2273).
- Specify how to obtain a Ruby thread's id (#2508).
- Refactor jvm classes semantic conventions (#2550).
- Add browser.* attributes (#2353).
- Change JVM runtime metric
process.runtime.jvm.memory.max
toprocess.runtime.jvm.memory.limit
(#2605). - Add semantic conventions for hardware metrics (#2518).
- No changes.
- No changes.
- No changes.
- No changes.
- Move non-otlp.md to common directory (#2587).
- No changes.
- No changes.
- Clarify that API support for multi-instrument callbacks is permitted. (#2263).
- Drop histogram aggregation, default to explicit bucket histogram (#2429)
- Clarify SDK behavior when view conflicts are present (#2462).
- Add support for exemplars on OpenMetrics counters (#2483)
- Clarify MetricReader.Collect result (#2495).
- Add database connection pool metrics semantic conventions (#2273).
- Update
com.google.*
togcp.*
in logs data model (#2514).
- No changes.
- Note added that
net.peer.name
SHOULD NOT be set if capturing it would require an extra reverse DNS lookup. And movednet.peer.name
from common http attributes to just client http attributes. (#2446) - Add
net.host.name
andnet.host.ip
conventions for rpc server spans. (#2447) - Allow all metric conventions to be either synchronous or asynchronous. (#2458
- Update JVM metrics with JMX Gatherer values (#2478)
- Add HTTP/3 (#2507)
- Map SunOS to solaris for os.type resource attribute (#2509)
- No changes.
- Clarify gRPC insecure option (#2476)
- Specify that OTLP/gRPC clients should retry on
RESOURCE_EXHAUSTED
code only if the server signals backpressure to indicate a possible recovery. (#2480)
- No changes.
- No changes.
- Define semantic conventions and instrumentation stability. (#2180)
- Loosen requirement for a major version bump (#2510).
- No changes.
- Introduce the concept of Instrumentation Scope to replace/extend Instrumentation Library. The Tracer is now associated with Instrumentation Scope (#2276).
- Add
OTEL_EXPORTER_JAEGER_PROTOCOL
environment variable to select the protocol used by the Jaeger exporter. (#2341) - Add documentation REQUIREMENT for adding attributes at span creation. (#2383).
- Initial Prometheus <-> OTLP datamodel specification (#2266)
- Introduce the concept of Instrumentation Scope to replace/extend Instrumentation Library. The Meter is now associated with Instrumentation Scope (#2276).
- Specify the behavior of duplicate instrumentation registration in the API, specify duplicate conflicts in the data model, specify how the SDK is meant to report and assist the user when these conflicts arise. (#2317).
- Clarify that expectations for user callback behavior are documentation REQUIREMENTs. (#2361).
- Specify how to handle prometheus exemplar timestamp and attributes (#2376)
- Clarify that the periodic metric reader is the default metric reader to be paired with push metric exporters (OTLP, stdout, in-memory) (#2379).
- Convert OpenMetrics Info and StateSet metrics to non-monotonic sums (#2380)
- Clarify that MetricReader has one-to-one mapping to MeterProvider. (#2406).
- For prometheus metrics without sums, leave the sum unset (#2413)
- Specify default configuration for a periodic metric reader that is associated with the stdout metric exporter. (#2415).
- Clarify the manner in which aggregation and temporality preferences
are encoded via MetricReader parameters "on the basis of instrument
kind". Rename the environment variable
OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE
used to set the preference to be used when auto-configuring an OTLP Exporter, defaults to CUMULATIVE, with DELTA an option that makes Counter, Asynchronous Counter, and Histogram instruments choose Delta temporality by default. (#2404). - Clarify that instruments are enabled by default, even when Views are configured.
Require support for the match-all View expression having
name=*
to support disabling instruments by default. (#2417). - Mark Metrics SDK spec as Mixed, with most components moving to Stable, while Exemplar remaining Feature-freeze. (#2304)
- Clarify how metric metadata and type suffixes are handled (#2440)
- Add draft logging library SDK specification (#2328)
- Add InstrumentationScope/Logger Name to log data model (#2359)
- Remove
flush
method on LogEmitter (#2405) - Declare Log Data Model Stable (#2387)
- No changes.
- Define span structure for HTTP retries and redirects. (#2078)
- Changed
rpc.system
to an enum (allowing custom values), and changed therpc.system
value for .NET WCF fromwcf
todotnet_wcf
. (#2377) - Define JavaScript runtime semantic conventions. (#2290)
- Add semantic conventions for CloudEvents. (#1978)
- Add
process.cpu.utilization
metric. (#2436) - Add
rpc.system
value for Apache Dubbo. (#2453)
- Mark the OpenTracing compatibility section as stable. (#2327)
- Add experimental JSON serialization format (#2235)
- Parameters for private key and its chain added (#2370)
- No changes.
- No changes.
- Describe how to convert non-string primitives for protocols which only support strings (#2343)
- Add "Mapping Arbitrary Data to OTLP AnyValue" document. (#2385)
- No changes.
- Clarify
StartSpan
returning the parent as a non-recording Span when no SDK is in use. (#2121) - Align Jaeger remote sampler endpoint with OTLP endpoint. (#2246)
- Add JaegerRemoteSampler spec. (#2222)
- Add support for probability sampling in the OpenTelemetry
tracestate
entry and add optional specification for consistent probability sampling. (#2047) - Change description and default value of
OTEL_EXPORTER_JAEGER_ENDPOINT
environment variable to point to the correct HTTP port and correct description ofOTEL_TRACES_EXPORTER
. (#2333)
- Rename None aggregation to Drop. (#2101)
- Add details to the Prometheus Exporter requirements. (#2124)
- Consolidate the aggregation/aggregator term. (#2153)
- Remove the concept of supported temporality, keep preferred. (#2154)
- Rename extra dimensions to extra attributes. (#2162)
- Mark In-memory, OTLP and Stdout exporter specs as Stable. (#2175)
- Remove usage of baggage in View from initial SDK specification. (#2215)
- Add to the supplemental guidelines for metric SDK authors text about implementing attribute-removal Views for asynchronous instruments. (#2208)
- Clarify integer count instrument units. (#2210)
- Use UCUM units in Metrics Semantic Conventions. (#2199)
- Add semantic conventions for process metrics. #2032
- Changed default Prometheus Exporter host from
0.0.0.0
tolocalhost
. (#2282) - Clarified wildcard and predicate support in metrics SDK View API. (#2325)
- Changed the Exemplar wording, exemplar should be turned off by default. (#2414)
- Fix attributes names in Google Cloud Logging mapping. (#2093)
- Add OTEL_LOGS_EXPORTER environment variable. (#2196)
- Added ObservedTimestamp to the Log Data Model. (#2184)
- Change mapping for log_name of Google Cloud Logging. (#2092)
- Drop Log name. field (#2271)
- No changes.
- Align runtime metric and resource namespaces (#2112)
- Prohibit usage of retired names in semantic conventions. (#2191)
- Add
device.manufacturer
to describe mobile device manufacturers. (2100) - Change golang namespace to 'go', rather than 'gc' (#2262)
- Add JVM memory runtime semantic conventions. (#2272)
- Add opentracing.ref_type semantic convention. (#2297)
- Simplify Baggage handling in the OpenTracing Shim layer. (#2194)
- State that ONLY error mapping can happen in the OpenTracing Shim layer. (#2148)
- Define the instrumentation library name for the OpenTracing Shim. (#2227)
- Add a Start Span section to the OpenTracing Shim. (#2228)
- Rename
OTEL_EXPORTER_OTLP_SPAN_INSECURE
toOTEL_EXPORTER_OTLP_TRACES_INSECURE
andOTEL_EXPORTER_OTLP_METRIC_INSECURE
toOTEL_EXPORTER_OTLP_METRICS_INSECURE
so they match the naming of all other OTLP environment variables. (#2240)
- No changes.
- No changes.
- Add a section for OTel specific values in TraceState. (#1852)
- Add
none
as a possible value forOTEL_PROPAGATORS
to disable context propagation. (#2052)
- No changes.
- Add optional min / max fields to histogram data model. (#1915, #1983)
- Add exponential histogram to the metrics data model. (#1935)
- Add clarifications on how to handle numerical limits. (#2007)
- Add environment variables for Periodic exporting MetricReader. (#2038)
- Specify that the SDK must support exporters to access meter information. (#2040)
- Add clarifications on how to determine aggregation temporality. (#2013, #2032)
- Mark Metrics API spec as Stable. (#2104)
- Clarify, fix and expand documentation sections: (#1966), (#1981), (#1995), (#2002), (#2010)
- No changes.
- Add
k8s.container.restart_count
Resource attribute. (#1945) - Add "IBM z/Architecture" (
s390x
) tohost.arch
(#2055) - BREAKING: Remove db.cassandra.keyspace and db.hbase.namespace, and clarify db.name (#1973)
- Add AWS App Runner as a cloud platform (#2004)
- Add Tencent Cloud as a cloud provider. (#2006)
- Don't set Span.Status for 4xx http status codes for SERVER spans. (#1998)
- Add attributes for Apache RocketMQ. (#1904)
- Define http tracing attributes provided at span creation time (#1916)
- Change meaning and discourage use of
faas.trigger
for FaaS clients (outgoing). (#1921) - Clarify difference between container.name and k8s.container.name (#1980)
- No changes.
- Clarify default for OTLP endpoint should, not must, be https (#1997)
- Specify the behavior of the OTLP endpoint variables for OTLP/HTTP more strictly (#1975, #1985)
- Make OTLP/HTTP the recommended default transport (#1969)
- Unset and empty environment variables are equivalent. (#2045)
Added telemetry schemas documents to the specification (#2008)
- No changes.
- Prefer global user defined limits over model-specific default values. (#1893)
- Generalize the "message" event to apply to all RPC systems not just gRPC (#1914)
- Added Experimental Metrics SDK specification. (#1673, #1730, #1840, #1842, #1864, #1828, #1888, #1912, #1913, #1938, #1958)
- Add FaaS metrics semantic conventions (#1736)
- Update env variable values to match other env variables (#1965)
- No changes.
- Exempt Resource from attribute limits. (#1892)
- BREAKING: Change enum member IDs to lowercase without spaces, not starting with numbers.
Change values of
net.host.connection.subtype
to match. (#1863) - Lambda instrumentations should check if X-Ray parent context is valid (#1867)
- Update YAML definitions for events
(#1843):
- Mark exception as semconv type "event".
- Add YAML definitions for grpc events.
- Add
messaging.consumer_id
to differentiate between message consumers. (#1810) - Clarifications for
http.client_ip
andhttp.host
. (#1890) - Add HTTP request and response headers semantic conventions. (#1898)
- No changes.
- Add environment variables for configuring the OTLP exporter protocol (
grpc
,http/protobuf
,http/json
) (#1880) - Allow implementations to use their own default for OTLP compression, with
none
denotating no compression (#1923) - Clarify OTLP server components MUST support none/gzip compression (#1955)
- Change OTLP/HTTP port from 4317 to 4318 (#1970)
- Change default value for OTEL_EXPORTER_JAEGER_AGENT_PORT to 6831. (#1812)
- See also the changes for OTLP configuration listed under "OpenTelemetry Protocol" above.
- No changes.
- Add generalized attribute count and attribute value length limits and relevant environment variables. (#1130)
- Adding environment variables for event and link attribute limits. (#1751)
- Adding SDK configuration for Jaeger remote sampler (#1791)
- Metrics API specification Feature-freeze. (#1833)
- Remove MetricProcessor from the SDK spec (for now) (#1840)
- No changes.
- No changes.
- Add mobile-related network state:
net.host.connection.type
,net.host.connection.subtype
&net.host.carrier.*
#1647 - Adding alibaba cloud as a cloud provider. (#1831)
- No changes.
- Allow for OTLP/gRPC exporters to handle endpoint configuration without a scheme while still requiring them to support an endpoint configuration that includes a scheme of
http
orhttps
. Reintroduce the insecure configuration option for OTLP/gRPC exporters. (#1729) - Adding requirement to implement at least one of two transports:
grpc
orhttp/protobuf
. (#1790)
- No changes.
- No changes.
- Adding environment variables for event and link attribute limits. (#1751)
- Clarify some details about span kind and the meanings of the values. (#1738)
- Clarify meaning of the Certificate File option. (#1803)
- Adding environment variables for event and link attribute limits. (#1751)
- Clarify the limit on the instrument unit. (#1762)
- Declare OTLP Logs Beta. (#1741)
- No changes.
- Clean up FaaS semantic conventions, add
aws.lambda.invoked_arn
. (#1781) - Remove
rpc.jsonrpc.method
, clarify thatrpc.method
should be used instead. (#1748)
- No changes.
- No changes.
- Allow selecting multiple exporters via
OTEL_TRACES_EXPORTER
andOTEL_METRICS_EXPORTER
by using a comma-separated list. (#1758)
- No changes.
- Add schema_url support to
Tracer
. (#1666) - Add Dropped Links Count to non-otlp exporters section (#1697)
- Add note about reporting dropped counts for attributes, events, links. (#1699)
- Add schema_url support to
Meter
. (#1666) - Adds detail about when to use
StartTimeUnixNano
and handling of unknown start-time resets. (#1646) - Expand
Gauge
metric description in the data model (#1661) - Expand
Histogram
metric description in the data model (#1664) - Added Experimental Metrics API specification. (#1401, #1557, #1578, #1590, #1594, #1617, #1645, #1657, #1665, #1672, #1674, #1675, #1703, #1704, #1731, #1733)
- Mark relevant portions of Metrics Data Model stable (#1728)
- No changes.
- Add schema_url support to
Resource
. (#1692) - Clarify result of Resource merging and ResourceDetector aggregation in case of error. (#1726)
- Add JSON RPC specific conventions (#1643).
- Add Memcached to Database specific conventions (#1689).
- Add semantic convention attributes for the host device and added OS name and version (#1596).
- Add CockroachDB to Database specific conventions (#1725).
- No changes.
- No changes.
- Add
OTEL_SERVICE_NAME
environment variable. (#1677)
- No changes.
Get Tracer
should use an empty string if the specifiedname
is null. (#1654)- Clarify how to record dropped attribute count in non-OTLP formats. (#1662)
- Expand description of Event Model and Instruments. (#1614)
- Flesh out metric identity and single-write principle. (#1574)
- Expand
Sum
metric description in the data model and delta-to-cumulative handling. (#1618) - Remove the "Func" name, use "Asynchronous" and "Observable". (#1645)
- Add details to UpDownCounter API. (#1665)
- Add details to Histogram API. (#1657)
- Clarify "key/value pair list" vs "map" in Log Data Model. (#1604)
- Fix the inconsistent formatting of semantic convention enums. (#1598)
- Add details for filling resource for AWS Lambda. (#1610)
- Add already specified
messaging.rabbitmq.routing_key
span attribute key to the respective YAML file. (#1651) - Clarify usage of "otel." attribute namespace. (#1640)
- Add possibility to disable
db.statement
via instrumentation configuration. (#1659)
- No changes.
- Fix incorrect table of transient errors. (#1642)
- Clarify that 64 bit integer numbers are decimal strings in OTLP/JSON. (#1637)
- Add
OTEL_EXPORTER_JAEGER_TIMEOUT
environment variable. (#1612) - Add
OTEL_EXPORTER_ZIPKIN_TIMEOUT
environment variable. (#1636)
- Clarify composite
TextMapPropagator
method required and optional arguments. (#1541) - Clarify B3 requirements and configuration. (#1570)
- Add
ForceFlush
toSpan Exporter
interface (#1467) - Clarify the description for the
TraceIdRatioBased
sampler needs to include the sampler's sampling ratio. (#1536) - Define the fallback tracer name for invalid values. (#1534)
- Clarify non-blocking requirement from span API End. (#1555)
- Remove the Included Propagators section from trace API specification that was a duplicate of the Propagators Distribution of the context specification. (#1556)
- Remove the Baggage API propagator notes that conflict with the API Propagators Operations section and fix #1526. (#1575)
- Adds new metric data model specification (#1512)
- Add semantic conventions for AWS SDK operations and DynamoDB (#1422)
- Add details for filling semantic conventions for AWS Lambda (#1442)
- Update semantic conventions to distinguish between int and double (#1550)
- Add semantic convention for AWS ECS task revision (#1581)
- Add initial OpenTracing compatibility section. (#1101)
- Implementations can ignore links with invalid SpanContext(#1492)
- Add
none
as a possible value for OTEL_TRACES_EXPORTER to disable export (#1439) - Add
ForceFlush
to SDK'sTracerProvider
(#1452)
- Add
none
as a possible value for OTEL_METRICS_EXPORTER to disable export (#1439)
- Add
elasticsearch
todb.system
semantic conventions (#1463) - Add
arch
tohost
semantic conventions (#1483) - Add
runtime
tocontainer
semantic conventions (#1482) - Rename
gcp_gke
togcp_kubernetes_engine
to have consistency with other Google products undercloud.infrastructure_service
(#1496) http.url
MUST NOT contain credentials (#1502)- Add
aws.eks.cluster.arn
to EKS specific semantic conventions (#1484) - Rename
zone
toavailability_zone
incloud
semantic conventions (#1495) - Rename
cloud.infrastructure_service
tocloud.platform
(#1530) - Add section describing that libraries and the collector should autogenerate the semantic convention keys. (#1515)
- Fix rebase issue for span limit default values (#1429)
New:
- Add
cloud.infrastructure_service
resource attribute (#1112) - Add
SpanLimits
as a configuration for the TracerProvider(#1416)
Updates:
- Add
http.server.active_requests
to count in-flight HTTP requests (#1378) - Update default limit for span attributes, events, links to 128(#1419)
- Update OT Trace propagator environment variable to match latest name(#1406)
- Remove Metrics SDK specification to avoid confusion, clarify that Metrics API specification is not recommended for client implementation (#1401)
- Rename OTEL_TRACE_SAMPLER and OTEL_TRACE_SAMPLER_ARG env variables to OTEL_TRACES_SAMPLER and OTEL_TRACES_SAMPLER_ARG (#1382)
- Mark some entries in compliance matrix as optional(#1359) SDKs are free to provide support at their discretion.
- Rename signal-specific variables for
OTLP_EXPORTER_*
toOTLP_EXPORTER_TRACES_*
andOTLP_EXPORTER_METRICS_*
(#1362) - Versioning and stability guarantees for OpenTelemetry clients(#1291)
- Additional Cassandra semantic attributes (#1217)
- OTEL_EXPORTER environment variable replaced with OTEL_TRACES_EXPORTER and OTEL_METRICS_EXPORTER which each accept only a single value, not a list. (#1318)
process.runtime.description
resource convention: Addjava.vm.name
(#1242)- Refine span name guideline for SQL database spans (#1219)
- Add RPC semantic conventions for metrics (#1162)
- Clarify
Description
usage onStatus
API (#1257) - Add/Update
Status
+error
mapping for Jaeger & Zipkin Exporters (#1257) - Resource's service.name MUST have a default value, service.instance.id is not
required.
(#1269)
- Clarified in #1294
- Add requirement that the SDK allow custom generation of Trace IDs and Span IDs (#1006)
- Add default ratio when TraceIdRatioSampler is specified by environment variable but no ratio is. (#1322)
- Require schemed endpoints for OTLP exporters (1234)
- Resource SDK: Reverse (suggested) order of Resource.Merge parameters, remove special case for empty strings (#1345)
- Resource attributes: lowerecased the allowed values of the
aws.ecs.launchtype
attribute (#1339) - Trace Exporters: Fix TODOs in Jaeger exporter spec (#1374)
- Clarify that Jaeger/Zipkin exporters must rely on the default Resource to get service.name if none was specified. (#1386)
- Modify OTLP/Zipkin Exporter format variables for 1.0 (allowing further specification post 1.0) (#1358)
- Add
k8s.node
semantic conventions (#1390) - Clarify stability for both OTLP/HTTP and signals in OTLP. (#1400)
New:
- Document service name mapping for Jaeger exporters (1222)
- Change default OTLP port number (#1221)
- Add performance benchmark specification (#748)
- Enforce that the Baggage API must be fully functional, even without an installed SDK. (#1103)
- Rename "Canonical status code" to "Status code" (#1081)
- Add Metadata for Baggage entries, and clarify W3C Baggage Propagator implementation (#1066)
- Change Status to be consistent with Link and Event (#1067)
- Clarify env variables in otlp exporter (#975)
- Add Prometheus exporter environment variables (#1021)
- Default propagators in un-configured API must be no-op (#930)
- Define resource mapping for Jaeger exporters (#891)
- Add resource semantic conventions for operating systems (#693)
- Add semantic convention for source code attributes (#901)
- Add semantic conventions for outgoing Function as a Service (FaaS) invocations (#862)
- Add resource semantic convention for deployment environment (#606)
- Refine semantic conventions for messaging systems and add specific attributes for Kafka (#1027)
- Clarification of the behavior of the Trace API, re: context propagation, in the absence of an installed SDK
- Add API and semantic conventions for recording exceptions as Span Events (#697)
- Allow samplers to modify tracestate (#988)
- Update the header name for otel baggage, and version date (#981)
- Define PropagationOnly Span to simplify active Span logic in Context (#994)
- Add limits to the number of attributes, events, and links in SDK Spans (#942)
- Add Metric SDK specification (partial): covering terminology and Accumulator component (#626)
- Clarify context interaction for trace module (#1063)
- Add
Shutdown
function to*Provider
SDK (#1074) - Add semantic conventions for system metrics (#937)
- Add
db.sql.table
to semantic conventions, allowdb.operation
for SQL (#1141) - Add OTEL_TRACE_SAMPLER env variable definition (#1136)
- Add guidelines for OpenMetrics interoperability (#1154)
- Add OTEL_TRACE_SAMPLER_ARG env variable definition (#1202)
Updates:
- Clarify null SHOULD NOT be allowed even in arrays (#1214)
- Remove ordering SHOULD-requirement for attributes (#1212)
- Make
process.pid
optional, splitprocess.command_args
fromcommand_line
(#1137) - Renamed
CorrelationContext
toBaggage
: (#857) - Add semantic convention for NGINX custom HTTP 499 status code.
- Adapt semantic conventions for the span name of messaging systems (#690)
- Remove lazy Event and Link API from Span interface
(#840)
- SIGs are recommended to remove any existing implementation of the lazy APIs to avoid conflicts/breaking changes in case they will be reintroduced to the spec in future.
- Provide clear definitions for readable and read/write span interfaces in the
SDK
(#669)
- SpanProcessors must provide read/write access at least in OnStart.
- Specify how
Probability
sampler is used withParentOrElse
sampler. - Clarify event timestamp origin and range (#839)
- Clean up api-propagators.md, by extending documentation and removing redundant sections (#577)
- Rename HTTPText propagator to TextMap (#793)
- Rename ParentOrElse sampler to ParentBased and add multiple delegate samplers (#610)
- Rename ProbabilitySampler to TraceIdRatioBasedSampler and add requirements (#611)
- Version attributes no longer have a prefix such as semver: (#873)
- Add semantic conventions for process runtime (#882, #1137)
- Use hex encoding for trace id and span id fields in OTLP JSON encoding: (#911)
- Explicitly specify the SpanContext APIs IsValid and IsRemote as required (#914)
- A full
Context
is the only way to specify a parent of aSpan
.SpanContext
or evenSpan
are not allowed anymore. (#875) - Remove obsolete
http.status_text
from semantic conventions (#972) - Define
null
as an invalid value for attributes and declare attempts to setnull
as undefined behavior (#992) - SDK: Rename the
Decision
values forSamplingResult
s toDROP
,RECORD_ONLY
andRECORD_AND_SAMPLE
for consistency (#938, #956) - Metrics API: Replace "Additive" with "Adding", "Non-Additive" with "Grouping" (#983
- Move active span interaction in the Trace API to a separate class (#923)
- Metrics SDK: Specify LastValue default aggregation for ValueObserver (#984
- Metrics SDK: Specify TBD default aggregation for ValueRecorder (#984
- Trace SDK: Sampler.ShouldSample gets parent Context instead of SpanContext (#881)
- SDK: Specify known values, as well as basic error handling for OTEL_PROPAGATORS. (#962) (#995)
- SDK: Specify when to generate new IDs with sampling (#1225)
- Remove custom header name for Baggage, use official header (#993)
- Trace API: Clarifications for
Span.End
, e.g. IsRecording becomes false after End (#1011) - Update semantic conventions for gRPC for new Span Status (#1156)
New:
- Add span attribute to indicate cold starts of Function as a Service executions (#650)
- Add conventions for naming of exporter packages (#629)
- Add semantic conventions for container id (#673)
- Add semantic conventions for HTTP content length (#641)
- Add semantic conventions for process resource (#635)
- Add peer.service to provide a user-configured name for a remote service (#652)
Updates:
- Improve root Span description (#645)
- Extend semantic conventions for RPC and allow non-gRPC calls (#604)
- Revise and extend semantic conventions for databases (#575)
- Clarify Tracer vs TracerProvider in tracing API and SDK spec.
(#619)
Most importantly:
- Configuration should be stored not per Tracer but in the TracerProvider.
- Active spans are not per Tracer.
- Do not set any value in Context upon failed extraction (#671)
- Clarify semantic conventions around span start and end time (#592)
- Define Log Data Model.
- Remove SpanId from Sampler input.
- Clarify what it will mean for a vendor to "support OpenTelemetry".
- Clarify Tracers should reference an InstrumentationLibrary rather than a Resource.
- Replace ALWAYS_PARENT sampler with a composite ParentOrElse sampler.
- Incorporate old content on metrics calling conventions, label sets.
- Update api-metrics-user.md and api-metrics-meter.md with the latest metrics API.
- Normalize Instrumentation term for instrumentations.
- Change w3c correlation context to custom header.
- OTEP-83 Introduce the notion of InstrumentationLibrary.
- OTEP-88 Metrics API instrument foundation.
- OTEP-91 Logs vocabulary.
- OTEP-92 Logs Vision.
- OTEP-90 Remove LabelSet from the metrics API.
- OTEP-98 Explain the metric instruments.
- OTEP-99 OTLP/HTTP: HTTP Transport Extension for OTLP.
- Define handling of null and empty attribute values.
- Rename Setter.put to Setter.set
- Add glossary for typically misused terms.
- Clarify that resources are immutable.
- Clarify that SpanContext.IsRemote is false on remote children.
- Move specifications into sub-directories per signal.
- Remove references to obsolete
peer.*
attributes. - Span semantic conventions for for messaging systems.
- Span semantic conventions for function as a service.
- Remove the handling of retries from trace exporters.
- Remove Metrics' default keys.
- Add some clarifying language to the semantics of metric instrument naming.
- Allow injectors and extractors to be separate interfaces.
- Add an explanation on why Context Restore operation is needed.
- Document special Zipkin conversion cases.
- OTEP-0059 Add OTLP Trace Data Format specification.
- OTEP-0066 Separate Layer for Context Propagation.
- OTEP-0070 Rename metric instrument "Handles" to "Bound Instruments".
- OTEP-0072 Metric Observer instrument specification (refinement).
- OTEP-0080 Remove the Metric Gauge instrument, recommend use of other instruments.
- Update 0003-measure-metric-type to match current Specification.
- Update 0009-metric-handles to match current Specification.
- Clarify named tracers and meters.
- Remove SamplingHint from the Sampling OTEP (OTEP-0006).
- Remove component attribute.
- Allow non-string Resource label values.
- Allow array values for attributes.
- Add service version to Resource attributes.
- Add general, general identity, network and VM image attribute conventions.
- Add a section on transformation to Zipkin Spans.
- Add a section on SDK default configuration.
- Enhance semantic conventions for HTTP/RPC.
- Provide guidelines for low-cardinality span names.
- SDK Tracer: Replace TracerFactory with TracerProvider.
- Update Resource to be in the SDK.
- OTEP-0001 Added Auto-Instrumentation.
- OTEP-0002: Removed SpanData interface in favor of Span Start and End options.
- OTEP-0003 Consolidatesd pre-aggregated and raw metrics APIs.
- OTEP-0008 Added Metrics Observers API.
- OTEP-0009 Added Metrics Handle API.
- OTEP-0010 Rename "Cumulative" to "Counter" in the Metrics API.
- OTEP-006 Moved sampling from the API tp the SDK.
- OTEP-0007 Moved support for out-of-band telemetry from the API to the SDK.
- OTEP-0016 Added named providers for Tracers and Meters.
- Added design goals and requirements for a telemetry data exchange protocol.
- Added a Span Processor interface for intercepting span start and end invocations.
- Added a Span Exporter interface for processing batches of spans.
- Replaced DistributedContext.GetIterator with GetEntries.
- Added clarifications and adjustments to improve cross-language applicability.
- Added a specification for SDK configuration.
- Added API proposal for the converged OpenTracing/OpenCensus project is complete.