Compliance of Implementations with Specification

The following tables show which features are implemented by the Haskell OpenTelemetry implementation.

+ means the feature is supported, - means it is not supported, N/A means the feature is not applicable to the particular language, blank cell means the status of the feature is not known.

For the Optional column, X means the feature is optional, blank means the feature is required, and columns marked with * mean that for each type of exporter (OTLP, Zipkin, and Jaeger), implementing at least one of the supported formats is required. Implementing more than one format is optional.

Traces

Feature	Optional	Haskell
TracerProvider		+
Create TracerProvider		+
Get a Tracer		+
Get a Tracer with schema_url		(partial)
Safe for concurrent calls		+
Shutdown (SDK only required)		+
ForceFlush (SDK only required)		+
Trace / Context interaction		+
Get active Span		+
Set active Span		+
Tracer		+
Create a new Span		+
Get active Span		+
Mark Span active		+
Safe for concurrent calls		+
SpanContext		+
IsValid		+
IsRemote		+
Conforms to the W3C TraceContext spec		(partial)
Span		+
Create root span		+
Create with default parent (active span)		+
Create with parent from Context		+
No explicit parent Span/SpanContext allowed		+
Processor.OnStart receives parent Context		+
UpdateName		+
User-defined start timestamp		+
End		+
End with timestamp		+
IsRecording		+
IsRecording becomes false after End		+
Set status with StatusCode (Unset, Ok, Error)		+
Safe for concurrent calls		+
events collection size limit		+
attribute collection size limit		+
links collection size limit		+
Span attributes		+
SetAttribute		+
Set order preserved	X
String type		+
Boolean type		+
Double floating-point type		+
Signed int64 type		+
Array of primitives (homogeneous)		+
null values documented as invalid/undefined		N/A
Unicode support for keys and string values		+
Span linking		+
Links can be recorded on span creation		+
Links order is preserved		+
Span events		+
AddEvent		+
Add order preserved		+
Safe for concurrent calls		+
Span exceptions		+
RecordException		+
RecordException with extra parameters		+
Sampling		+
Allow samplers to modify tracestate		+
ShouldSample gets full parent Context		+
ShouldSample gets InstrumentationLibrary		+
New Span ID created also for non-recording Spans		+
IdGenerators		+
SpanLimits	X	+
Built-in Processors implement ForceFlush spec		+
Attribute Limits	X	+

Baggage

Feature	Optional	Haskell
Basic support		+
Use official header name baggage		+

Metrics

Feature	Optional	Haskell
TBD

Resource

Feature	Optional	Haskell
Create from Attributes		+
Create empty		+
Merge (v2)		?
Retrieve attributes		+
Default value for service.name		+

Context Propagation

Feature	Optional	Haskell
Create Context Key		+
Get value from Context		+
Set value for Context		+
Attach Context		+
Detach Context		+
Get current Context		+
Composite Propagator		+ (monoid instance)
Global Propagator		+
TraceContext Propagator		(partial support)
B3 Propagator
Jaeger Propagator
TextMapPropagator		+
Fields
Setter argument	X
Getter argument	X
Getter argument returning Keys	X

Environment Variables

Note: Support for environment variables is optional.

Feature	Haskell
OTEL_SDK_DISABLED	+
OTEL_RESOURCE_ATTRIBUTES	+
OTEL_SERVICE_NAME	+
OTEL_LOG_LEVEL
OTEL_PROPAGATORS	+
OTEL_BSP_*	+
OTEL_EXPORTER_OTLP_*	(partial support)
OTEL_EXPORTER_JAEGER_*
OTEL_EXPORTER_ZIPKIN_*
OTEL_TRACES_EXPORTER	(partial support)
OTEL_METRICS_EXPORTER
OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT	+
OTEL_SPAN_ATTRIBUTE_VALUE_LENGTH_LIMIT	+
OTEL_SPAN_EVENT_COUNT_LIMIT	+
OTEL_SPAN_LINK_COUNT_LIMIT	+
OTEL_EVENT_ATTRIBUTE_COUNT_LIMIT	+
OTEL_LINK_ATTRIBUTE_COUNT_LIMIT	+
OTEL_TRACES_SAMPLER	+
OTEL_TRACES_SAMPLER_ARG	+
OTEL_ATTRIBUTE_VALUE_LENGTH_LIMIT	+
OTEL_ATTRIBUTE_COUNT_LIMIT	+

Exporters

Feature	Optional	Haskell
Exporter interface		+
Exporter interface has ForceFlush		+
Standard output (logging)
In-memory (mock exporter)		+
OTLP		+
OTLP/gRPC Exporter	*
OTLP/HTTP binary Protobuf Exporter	*	+
OTLP/HTTP JSON Protobuf Exporter
OTLP/HTTP gzip Content-Encoding support	X	+
Concurrent sending
Honors retryable responses with backoff	X	+
Honors non-retryable responses	X	+
Honors throttling response	X	(partial support)
Multi-destination spec compliance	X
Zipkin
Zipkin V1 JSON	X
Zipkin V1 Thrift	X
Zipkin V2 JSON	*
Zipkin V2 Protobuf	*
Service name mapping
SpanKind mapping
InstrumentationLibrary mapping
Boolean attributes
Array attributes
Status mapping
Error Status mapping
Event attributes mapping to Annotations
Integer microseconds in timestamps
Jaeger
Jaeger Thrift over UDP	*
Jaeger Protobuf via gRPC	*
Jaeger Thrift over HTTP	*
Service name mapping
Resource to Process mapping
InstrumentationLibrary mapping
Status mapping
Error Status mapping
Events converted to Logs
OpenCensus
TBD
Prometheus
TBD