Protocol Buffers

Component

Field	Type	Label	Description
type	string
app	string
name	string
hash	string
id	string
broker_id	string

Event

Field	Type	Label	Description
id	string
parent_id	string
parent_span	SpanContext
type	string
category	Category
create_time	int64		Unix time in nanosecond
ttl	int64		TTL in nanosecond
context	EventContext
source	Component
target	Component
params	Event.ParamsEntry	repeated
values	Event.ValuesEntry	repeated
content_type	string
content	bytes

Event.ParamsEntry

Field	Type	Label	Description
key	string
value	google.protobuf.Value

Event.ValuesEntry

Field	Type	Label	Description
key	string
value	google.protobuf.Value

EventContext

Field	Type	Label	Description
platform	string
virtual_environment	string
app_deployment	string
release_manifest	string

MatchedEvent

Field	Type	Label	Description
event	Event
route_id	int64
env	MatchedEvent.EnvEntry	repeated

MatchedEvent.EnvEntry

Field	Type	Label	Description
key	string
value	google.protobuf.Value

SpanContext

Field	Type	Label	Description
trace_id	bytes
span_id	bytes
trace_state	string
flags	fixed32

Telemetry

Field	Type	Label	Description
trace_id	bytes
log_records	opentelemetry.proto.logs.v1.LogRecord	repeated
metrics	opentelemetry.proto.metrics.v1.Metric	repeated
spans	opentelemetry.proto.trace.v1.Span	repeated

Category

Name	Number	Description
UNKNOWN	0
MESSAGE	1
REQUEST	2
RESPONSE	3

Broker

Method Name	Request Type	Response Type	Description
Subscribe	Event stream	MatchedEvent stream

ListValue

ListValue is a wrapper around a repeated field of values.

The JSON representation for ListValue is JSON array.

Field	Type	Label	Description
values	Value	repeated	Repeated field of dynamically typed values.

Struct

Struct represents a structured data value, consisting of fields which map to dynamically typed values. In some languages, Struct might be supported by a native representation. For example, in scripting languages like JS a struct is represented as an object. The details of that representation are described together with the proto support for the language.

The JSON representation for Struct is JSON object.

Field	Type	Label	Description
fields	Struct.FieldsEntry	repeated	Unordered map of dynamically typed values.

Struct.FieldsEntry

Field	Type	Label	Description
key	string
value	Value

Value

Value represents a dynamically typed value which can be either null, a number, a string, a boolean, a recursive struct value, or a list of values. A producer of value is expected to set one of these variants. Absence of any variant indicates an error.

The JSON representation for Value is JSON value.

Field	Type	Label	Description
null_value	NullValue		Represents a null value.
number_value	double		Represents a double value.
string_value	string		Represents a string value.
bool_value	bool		Represents a boolean value.
struct_value	Struct		Represents a structured value.
list_value	ListValue		Represents a repeated Value.

NullValue

NullValue is a singleton enumeration to represent the null value for the Value type union.

The JSON representation for NullValue is JSON null.

Name	Number	Description
NULL_VALUE	0	Null value.

AnyValue

AnyValue is used to represent any type of attribute value. AnyValue may contain a primitive value such as a string or integer or it may contain an arbitrary nested object containing arrays, key-value lists and primitives.

Field	Type	Label	Description
string_value	string
bool_value	bool
int_value	int64
double_value	double
array_value	ArrayValue
kvlist_value	KeyValueList
bytes_value	bytes

ArrayValue

ArrayValue is a list of AnyValue messages. We need ArrayValue as a message since oneof in AnyValue does not allow repeated fields.

Field	Type	Label	Description
values	AnyValue	repeated	Array of values. The array may be empty (contain 0 elements).

InstrumentationScope

InstrumentationScope is a message representing the instrumentation scope information such as the fully qualified name and version.

Field	Type	Label	Description
name	string		An empty instrumentation scope name means the name is unknown.
version	string
attributes	KeyValue	repeated	Additional attributes that describe the scope. [Optional]. Attribute keys MUST be unique (it is not allowed to have more than one attribute with the same key).
dropped_attributes_count	uint32

KeyValue

KeyValue is a key-value pair that is used to store Span attributes, Link attributes, etc.

Field	Type	Label	Description
key	string
value	AnyValue

KeyValueList

KeyValueList is a list of KeyValue messages. We need KeyValueList as a message since oneof in AnyValue does not allow repeated fields. Everywhere else where we need a list of KeyValue messages (e.g. in Span) we use repeated KeyValue directly to avoid unnecessary extra wrapping (which slows down the protocol). The 2 approaches are semantically equivalent.

Field	Type	Label	Description
values	KeyValue	repeated	A collection of key/value pairs of key-value pairs. The list may be empty (may contain 0 elements). The keys MUST be unique (it is not allowed to have more than one value with the same key).

LogRecord

A log record according to OpenTelemetry Log Data Model: https://github.com/open-telemetry/oteps/blob/main/text/logs/0097-log-data-model.md

Field	Type	Label	Description
time_unix_nano	fixed64		time_unix_nano is the time when the event occurred. Value is UNIX Epoch time in nanoseconds since 00:00:00 UTC on 1 January 1970. Value of 0 indicates unknown or missing timestamp.
observed_time_unix_nano	fixed64		Time when the event was observed by the collection system. For events that originate in OpenTelemetry (e.g. using OpenTelemetry Logging SDK) this timestamp is typically set at the generation time and is equal to Timestamp. For events originating externally and collected by OpenTelemetry (e.g. using Collector) this is the time when OpenTelemetry's code observed the event measured by the clock of the OpenTelemetry code. This field MUST be set once the event is observed by OpenTelemetry. For converting OpenTelemetry log data to formats that support only one timestamp or when receiving OpenTelemetry log data by recipients that support only one timestamp internally the following logic is recommended: - Use time_unix_nano if it is present, otherwise use observed_time_unix_nano. Value is UNIX Epoch time in nanoseconds since 00:00:00 UTC on 1 January 1970. Value of 0 indicates unknown or missing timestamp.
severity_number	SeverityNumber		Numerical value of the severity, normalized to values described in Log Data Model. [Optional].
severity_text	string		The severity text (also known as log level). The original string representation as it is known at the source. [Optional].
body	opentelemetry.proto.common.v1.AnyValue		A value containing the body of the log record. Can be for example a human-readable string message (including multi-line) describing the event in a free form or it can be a structured data composed of arrays and maps of other values. [Optional].
attributes	opentelemetry.proto.common.v1.KeyValue	repeated	Additional attributes that describe the specific event occurrence. [Optional]. Attribute keys MUST be unique (it is not allowed to have more than one attribute with the same key).
dropped_attributes_count	uint32
flags	fixed32		Flags, a bit field. 8 least significant bits are the trace flags as defined in W3C Trace Context specification. 24 most significant bits are reserved and must be set to 0. Readers must not assume that 24 most significant bits will be zero and must correctly mask the bits when reading 8-bit trace flag (use flags & LOG_RECORD_FLAGS_TRACE_FLAGS_MASK). [Optional].
trace_id	bytes		A unique identifier for a trace. All logs from the same trace share the same trace_id. The ID is a 16-byte array. An ID with all zeroes OR of length other than 16 bytes is considered invalid (empty string in OTLP/JSON is zero-length and thus is also invalid). This field is optional. The receivers SHOULD assume that the log record is not associated with a trace if any of the following is true: - the field is not present, - the field contains an invalid value.
span_id	bytes		A unique identifier for a span within a trace, assigned when the span is created. The ID is an 8-byte array. An ID with all zeroes OR of length other than 8 bytes is considered invalid (empty string in OTLP/JSON is zero-length and thus is also invalid). This field is optional. If the sender specifies a valid span_id then it SHOULD also specify a valid trace_id. The receivers SHOULD assume that the log record is not associated with a span if any of the following is true: - the field is not present, - the field contains an invalid value.

LogsData

LogsData represents the logs data that can be stored in a persistent storage, OR can be embedded by other protocols that transfer OTLP logs data but do not implement the OTLP protocol.

The main difference between this message and collector protocol is that in this message there will not be any "control" or "metadata" specific to OTLP protocol.

When new fields are added into this message, the OTLP request MUST be updated as well.

Field	Type	Label	Description
resource_logs	ResourceLogs	repeated	An array of ResourceLogs. For data coming from a single resource this array will typically contain one element. Intermediary nodes that receive data from multiple origins typically batch the data before forwarding further and in that case this array will contain multiple elements.

ResourceLogs

A collection of ScopeLogs from a Resource.

Field	Type	Label	Description
resource	opentelemetry.proto.resource.v1.Resource		The resource for the logs in this message. If this field is not set then resource info is unknown.
scope_logs	ScopeLogs	repeated	A list of ScopeLogs that originate from a resource.
schema_url	string		The Schema URL, if known. This is the identifier of the Schema that the resource data is recorded in. To learn more about Schema URL see https://opentelemetry.io/docs/specs/otel/schemas/#schema-url This schema_url applies to the data in the "resource" field. It does not apply to the data in the "scope_logs" field which have their own schema_url field.

ScopeLogs

A collection of Logs produced by a Scope.

Field	Type	Label	Description
scope	opentelemetry.proto.common.v1.InstrumentationScope		The instrumentation scope information for the logs in this message. Semantically when InstrumentationScope isn't set, it is equivalent with an empty instrumentation scope name (unknown).
log_records	LogRecord	repeated	A list of log records.
schema_url	string		The Schema URL, if known. This is the identifier of the Schema that the log data is recorded in. To learn more about Schema URL see https://opentelemetry.io/docs/specs/otel/schemas/#schema-url This schema_url applies to all logs in the "logs" field.

LogRecordFlags

LogRecordFlags represents constants used to interpret the LogRecord.flags field, which is protobuf 'fixed32' type and is to be used as bit-fields. Each non-zero value defined in this enum is a bit-mask. To extract the bit-field, for example, use an expression like:

(logRecord.flags & LOG_RECORD_FLAGS_TRACE_FLAGS_MASK)

Name	Number	Description
LOG_RECORD_FLAGS_DO_NOT_USE	0	The zero value for the enum. Should not be used for comparisons. Instead use bitwise "and" with the appropriate mask as shown above.
LOG_RECORD_FLAGS_TRACE_FLAGS_MASK	255	Bits 0-7 are used for trace flags.

SeverityNumber

Possible values for LogRecord.SeverityNumber.

Name	Number	Description
SEVERITY_NUMBER_UNSPECIFIED	0	UNSPECIFIED is the default SeverityNumber, it MUST NOT be used.
SEVERITY_NUMBER_TRACE	1
SEVERITY_NUMBER_TRACE2	2
SEVERITY_NUMBER_TRACE3	3
SEVERITY_NUMBER_TRACE4	4
SEVERITY_NUMBER_DEBUG	5
SEVERITY_NUMBER_DEBUG2	6
SEVERITY_NUMBER_DEBUG3	7
SEVERITY_NUMBER_DEBUG4	8
SEVERITY_NUMBER_INFO	9
SEVERITY_NUMBER_INFO2	10
SEVERITY_NUMBER_INFO3	11
SEVERITY_NUMBER_INFO4	12
SEVERITY_NUMBER_WARN	13
SEVERITY_NUMBER_WARN2	14
SEVERITY_NUMBER_WARN3	15
SEVERITY_NUMBER_WARN4	16
SEVERITY_NUMBER_ERROR	17
SEVERITY_NUMBER_ERROR2	18
SEVERITY_NUMBER_ERROR3	19
SEVERITY_NUMBER_ERROR4	20
SEVERITY_NUMBER_FATAL	21
SEVERITY_NUMBER_FATAL2	22
SEVERITY_NUMBER_FATAL3	23
SEVERITY_NUMBER_FATAL4	24

Exemplar

A representation of an exemplar, which is a sample input measurement. Exemplars also hold information about the environment when the measurement was recorded, for example the span and trace ID of the active span when the exemplar was recorded.

Field	Type	Label	Description
filtered_attributes	opentelemetry.proto.common.v1.KeyValue	repeated	The set of key/value pairs that were filtered out by the aggregator, but recorded alongside the original measurement. Only key/value pairs that were filtered out by the aggregator should be included
time_unix_nano	fixed64		time_unix_nano is the exact time when this exemplar was recorded Value is UNIX Epoch time in nanoseconds since 00:00:00 UTC on 1 January 1970.
as_double	double
as_int	sfixed64
span_id	bytes		(Optional) Span ID of the exemplar trace. span_id may be missing if the measurement is not recorded inside a trace or if the trace is not sampled.
trace_id	bytes		(Optional) Trace ID of the exemplar trace. trace_id may be missing if the measurement is not recorded inside a trace or if the trace is not sampled.

ExponentialHistogram

ExponentialHistogram represents the type of a metric that is calculated by aggregating as a ExponentialHistogram of all reported double measurements over a time interval.

Field	Type	Label	Description
data_points	ExponentialHistogramDataPoint	repeated
aggregation_temporality	AggregationTemporality		aggregation_temporality describes if the aggregator reports delta changes since last report time, or cumulative changes since a fixed start time.

ExponentialHistogramDataPoint

ExponentialHistogramDataPoint is a single data point in a timeseries that describes the time-varying values of a ExponentialHistogram of double values. A ExponentialHistogram contains summary statistics for a population of values, it may optionally contain the distribution of those values across a set of buckets.

Field	Type	Label	Description
attributes	opentelemetry.proto.common.v1.KeyValue	repeated	The set of key/value pairs that uniquely identify the timeseries from where this point belongs. The list may be empty (may contain 0 elements). Attribute keys MUST be unique (it is not allowed to have more than one attribute with the same key).
start_time_unix_nano	fixed64		StartTimeUnixNano is optional but strongly encouraged, see the the detailed comments above Metric. Value is UNIX Epoch time in nanoseconds since 00:00:00 UTC on 1 January 1970.
time_unix_nano	fixed64		TimeUnixNano is required, see the detailed comments above Metric. Value is UNIX Epoch time in nanoseconds since 00:00:00 UTC on 1 January 1970.
count	fixed64		count is the number of values in the population. Must be non-negative. This value must be equal to the sum of the "bucket_counts" values in the positive and negative Buckets plus the "zero_count" field.
sum	double	optional	sum of the values in the population. If count is zero then this field must be zero. Note: Sum should only be filled out when measuring non-negative discrete events, and is assumed to be monotonic over the values of these events. Negative events can be recorded, but sum should not be filled out when doing so. This is specifically to enforce compatibility w/ OpenMetrics, see: https://github.com/OpenObservability/OpenMetrics/blob/main/specification/OpenMetrics.md#histogram
scale	sint32		scale describes the resolution of the histogram. Boundaries are located at powers of the base, where: base = (2(2-scale)) The histogram bucket identified by index, a signed integer, contains values that are greater than (base^index) and less than or equal to (base^(index+1)). The positive and negative ranges of the histogram are expressed separately. Negative values are mapped by their absolute value into the negative range using the same scale as the positive range. scale is not restricted by the protocol, as the permissible values depend on the range of the data.
zero_count	fixed64		zero_count is the count of values that are either exactly zero or within the region considered zero by the instrumentation at the tolerated degree of precision. This bucket stores values that cannot be expressed using the standard exponential formula as well as values that have been rounded to zero. Implementations MAY consider the zero bucket to have probability mass equal to (zero_count / count).
positive	ExponentialHistogramDataPoint.Buckets		positive carries the positive range of exponential bucket counts.
negative	ExponentialHistogramDataPoint.Buckets		negative carries the negative range of exponential bucket counts.
flags	uint32		Flags that apply to this specific data point. See DataPointFlags for the available flags and their meaning.
exemplars	Exemplar	repeated	(Optional) List of exemplars collected from measurements that were used to form the data point
min	double	optional	min is the minimum value over (start_time, end_time].
max	double	optional	max is the maximum value over (start_time, end_time].
zero_threshold	double		ZeroThreshold may be optionally set to convey the width of the zero region. Where the zero region is defined as the closed interval [-ZeroThreshold, ZeroThreshold]. When ZeroThreshold is 0, zero count bucket stores values that cannot be expressed using the standard exponential formula as well as values that have been rounded to zero.

ExponentialHistogramDataPoint.Buckets

Buckets are a set of bucket counts, encoded in a contiguous array of counts.

Field	Type	Label	Description
offset	sint32		Offset is the bucket index of the first entry in the bucket_counts array. Note: This uses a varint encoding as a simple form of compression.
bucket_counts	uint64	repeated	bucket_counts is an array of count values, where bucket_counts[i] carries the count of the bucket at index (offset+i). bucket_counts[i] is the count of values greater than base^(offset+i) and less than or equal to base^(offset+i+1). Note: By contrast, the explicit HistogramDataPoint uses fixed64. This field is expected to have many buckets, especially zeros, so uint64 has been selected to ensure varint encoding.

Gauge

Gauge represents the type of a scalar metric that always exports the "current value" for every data point. It should be used for an "unknown" aggregation.

A Gauge does not support different aggregation temporalities. Given the aggregation is unknown, points cannot be combined using the same aggregation, regardless of aggregation temporalities. Therefore, AggregationTemporality is not included. Consequently, this also means "StartTimeUnixNano" is ignored for all data points.

Field	Type	Label	Description
data_points	NumberDataPoint	repeated

Histogram

Histogram represents the type of a metric that is calculated by aggregating as a Histogram of all reported measurements over a time interval.

Field	Type	Label	Description
data_points	HistogramDataPoint	repeated
aggregation_temporality	AggregationTemporality		aggregation_temporality describes if the aggregator reports delta changes since last report time, or cumulative changes since a fixed start time.

HistogramDataPoint

HistogramDataPoint is a single data point in a timeseries that describes the time-varying values of a Histogram. A Histogram contains summary statistics for a population of values, it may optionally contain the distribution of those values across a set of buckets.

If the histogram contains the distribution of values, then both "explicit_bounds" and "bucket counts" fields must be defined. If the histogram does not contain the distribution of values, then both "explicit_bounds" and "bucket_counts" must be omitted and only "count" and "sum" are known.

Field	Type	Label	Description
attributes	opentelemetry.proto.common.v1.KeyValue	repeated	The set of key/value pairs that uniquely identify the timeseries from where this point belongs. The list may be empty (may contain 0 elements). Attribute keys MUST be unique (it is not allowed to have more than one attribute with the same key).
start_time_unix_nano	fixed64		StartTimeUnixNano is optional but strongly encouraged, see the the detailed comments above Metric. Value is UNIX Epoch time in nanoseconds since 00:00:00 UTC on 1 January 1970.
time_unix_nano	fixed64		TimeUnixNano is required, see the detailed comments above Metric. Value is UNIX Epoch time in nanoseconds since 00:00:00 UTC on 1 January 1970.
count	fixed64		count is the number of values in the population. Must be non-negative. This value must be equal to the sum of the "count" fields in buckets if a histogram is provided.
sum	double	optional	sum of the values in the population. If count is zero then this field must be zero. Note: Sum should only be filled out when measuring non-negative discrete events, and is assumed to be monotonic over the values of these events. Negative events can be recorded, but sum should not be filled out when doing so. This is specifically to enforce compatibility w/ OpenMetrics, see: https://github.com/OpenObservability/OpenMetrics/blob/main/specification/OpenMetrics.md#histogram
bucket_counts	fixed64	repeated	bucket_counts is an optional field contains the count values of histogram for each bucket. The sum of the bucket_counts must equal the value in the count field. The number of elements in bucket_counts array must be by one greater than the number of elements in explicit_bounds array.
explicit_bounds	double	repeated	explicit_bounds specifies buckets with explicitly defined bounds for values. The boundaries for bucket at index i are: (-infinity, explicit_bounds[i]] for i == 0 (explicit_bounds[i-1], explicit_bounds[i]] for 0 < i < size(explicit_bounds) (explicit_bounds[i-1], +infinity) for i == size(explicit_bounds) The values in the explicit_bounds array must be strictly increasing. Histogram buckets are inclusive of their upper boundary, except the last bucket where the boundary is at infinity. This format is intentionally compatible with the OpenMetrics histogram definition.
exemplars	Exemplar	repeated	(Optional) List of exemplars collected from measurements that were used to form the data point
flags	uint32		Flags that apply to this specific data point. See DataPointFlags for the available flags and their meaning.
min	double	optional	min is the minimum value over (start_time, end_time].
max	double	optional	max is the maximum value over (start_time, end_time].

Metric

Defines a Metric which has one or more timeseries. The following is a brief summary of the Metric data model. For more details, see:

https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/data-model.md

The data model and relation between entities is shown in the diagram below. Here, "DataPoint" is the term used to refer to any one of the specific data point value types, and "points" is the term used to refer to any one of the lists of points contained in the Metric.

• Metric is composed of a metadata and data.
• Metadata part contains a name, description, unit.
• Data is one of the possible types (Sum, Gauge, Histogram, Summary).

• DataPoint contains timestamps, attributes, and one of the possible value type fields.

  Metric +------------+ |name | |description | |unit | +------------------------------------+ |data |---> |Gauge, Sum, Histogram, Summary, ... | +------------+ +------------------------------------+

Data [One of Gauge, Sum, Histogram, Summary, ...] +-----------+ |... | // Metadata about the Data. |points |--+ +-----------+ | | +---------------------------+ | |DataPoint 1 | v |+------+------+ +------+ | +-----+ ||label |label |...|label | | | 1 |-->||value1|value2|...|valueN| | +-----+ |+------+------+ +------+ | | . | |+-----+ | | . | ||value| | | . | |+-----+ | | . | +---------------------------+ | . | . | . | . | . | . | . | +---------------------------+ | . | |DataPoint M | +-----+ |+------+------+ +------+ | | M |-->||label |label |...|label | | +-----+ ||value1|value2|...|valueN| | |+------+------+ +------+ | |+-----+ | ||value| | |+-----+ | +---------------------------+

Each distinct type of DataPoint represents the output of a specific aggregation function, the result of applying the DataPoint's associated function of to one or more measurements.

All DataPoint types have three common fields: - Attributes includes key-value pairs associated with the data point - TimeUnixNano is required, set to the end time of the aggregation - StartTimeUnixNano is optional, but strongly encouraged for DataPoints having an AggregationTemporality field, as discussed below.

Both TimeUnixNano and StartTimeUnixNano values are expressed as UNIX Epoch time in nanoseconds since 00:00:00 UTC on 1 January 1970.

TimeUnixNano

This field is required, having consistent interpretation across DataPoint types. TimeUnixNano is the moment corresponding to when the data point's aggregate value was captured.

Data points with the 0 value for TimeUnixNano SHOULD be rejected by consumers.

StartTimeUnixNano

StartTimeUnixNano in general allows detecting when a sequence of observations is unbroken. This field indicates to consumers the start time for points with cumulative and delta AggregationTemporality, and it should be included whenever possible to support correct rate calculation. Although it may be omitted when the start time is truly unknown, setting StartTimeUnixNano is strongly encouraged.

Field	Type	Label	Description
name	string		name of the metric.
description	string		description of the metric, which can be used in documentation.
unit	string		unit in which the metric value is reported. Follows the format described by http://unitsofmeasure.org/ucum.html.
gauge	Gauge
sum	Sum
histogram	Histogram
exponential_histogram	ExponentialHistogram
summary	Summary
metadata	opentelemetry.proto.common.v1.KeyValue	repeated	Additional metadata attributes that describe the metric. [Optional]. Attributes are non-identifying. Consumers SHOULD NOT need to be aware of these attributes. These attributes MAY be used to encode information allowing for lossless roundtrip translation to / from another data model. Attribute keys MUST be unique (it is not allowed to have more than one attribute with the same key).

MetricsData

MetricsData represents the metrics data that can be stored in a persistent storage, OR can be embedded by other protocols that transfer OTLP metrics data but do not implement the OTLP protocol.

The main difference between this message and collector protocol is that in this message there will not be any "control" or "metadata" specific to OTLP protocol.

When new fields are added into this message, the OTLP request MUST be updated as well.

Field	Type	Label	Description
resource_metrics	ResourceMetrics	repeated	An array of ResourceMetrics. For data coming from a single resource this array will typically contain one element. Intermediary nodes that receive data from multiple origins typically batch the data before forwarding further and in that case this array will contain multiple elements.

NumberDataPoint

NumberDataPoint is a single data point in a timeseries that describes the time-varying scalar value of a metric.

Field	Type	Label	Description
attributes	opentelemetry.proto.common.v1.KeyValue	repeated	The set of key/value pairs that uniquely identify the timeseries from where this point belongs. The list may be empty (may contain 0 elements). Attribute keys MUST be unique (it is not allowed to have more than one attribute with the same key).
start_time_unix_nano	fixed64		StartTimeUnixNano is optional but strongly encouraged, see the the detailed comments above Metric. Value is UNIX Epoch time in nanoseconds since 00:00:00 UTC on 1 January 1970.
time_unix_nano	fixed64		TimeUnixNano is required, see the detailed comments above Metric. Value is UNIX Epoch time in nanoseconds since 00:00:00 UTC on 1 January 1970.
as_double	double
as_int	sfixed64
exemplars	Exemplar	repeated	(Optional) List of exemplars collected from measurements that were used to form the data point
flags	uint32		Flags that apply to this specific data point. See DataPointFlags for the available flags and their meaning.

ResourceMetrics

A collection of ScopeMetrics from a Resource.

Field	Type	Label	Description
resource	opentelemetry.proto.resource.v1.Resource		The resource for the metrics in this message. If this field is not set then no resource info is known.
scope_metrics	ScopeMetrics	repeated	A list of metrics that originate from a resource.
schema_url	string		The Schema URL, if known. This is the identifier of the Schema that the resource data is recorded in. To learn more about Schema URL see https://opentelemetry.io/docs/specs/otel/schemas/#schema-url This schema_url applies to the data in the "resource" field. It does not apply to the data in the "scope_metrics" field which have their own schema_url field.

ScopeMetrics

A collection of Metrics produced by an Scope.

Field	Type	Label	Description
scope	opentelemetry.proto.common.v1.InstrumentationScope		The instrumentation scope information for the metrics in this message. Semantically when InstrumentationScope isn't set, it is equivalent with an empty instrumentation scope name (unknown).
metrics	Metric	repeated	A list of metrics that originate from an instrumentation library.
schema_url	string		The Schema URL, if known. This is the identifier of the Schema that the metric data is recorded in. To learn more about Schema URL see https://opentelemetry.io/docs/specs/otel/schemas/#schema-url This schema_url applies to all metrics in the "metrics" field.

Sum

Sum represents the type of a scalar metric that is calculated as a sum of all reported measurements over a time interval.

Field	Type	Label	Description
data_points	NumberDataPoint	repeated
aggregation_temporality	AggregationTemporality		aggregation_temporality describes if the aggregator reports delta changes since last report time, or cumulative changes since a fixed start time.
is_monotonic	bool		If "true" means that the sum is monotonic.

Summary

Summary metric data are used to convey quantile summaries, a Prometheus (see: https://prometheus.io/docs/concepts/metric_types/#summary) and OpenMetrics (see: https://github.com/OpenObservability/OpenMetrics/blob/4dbf6075567ab43296eed941037c12951faafb92/protos/prometheus.proto#L45) data type. These data points cannot always be merged in a meaningful way. While they can be useful in some applications, histogram data points are recommended for new applications.

Field	Type	Label	Description
data_points	SummaryDataPoint	repeated

SummaryDataPoint

SummaryDataPoint is a single data point in a timeseries that describes the time-varying values of a Summary metric.

Field	Type	Label	Description
attributes	opentelemetry.proto.common.v1.KeyValue	repeated	The set of key/value pairs that uniquely identify the timeseries from where this point belongs. The list may be empty (may contain 0 elements). Attribute keys MUST be unique (it is not allowed to have more than one attribute with the same key).
start_time_unix_nano	fixed64		StartTimeUnixNano is optional but strongly encouraged, see the the detailed comments above Metric. Value is UNIX Epoch time in nanoseconds since 00:00:00 UTC on 1 January 1970.
time_unix_nano	fixed64		TimeUnixNano is required, see the detailed comments above Metric. Value is UNIX Epoch time in nanoseconds since 00:00:00 UTC on 1 January 1970.
count	fixed64		count is the number of values in the population. Must be non-negative.
sum	double		sum of the values in the population. If count is zero then this field must be zero. Note: Sum should only be filled out when measuring non-negative discrete events, and is assumed to be monotonic over the values of these events. Negative events can be recorded, but sum should not be filled out when doing so. This is specifically to enforce compatibility w/ OpenMetrics, see: https://github.com/OpenObservability/OpenMetrics/blob/main/specification/OpenMetrics.md#summary
quantile_values	SummaryDataPoint.ValueAtQuantile	repeated	(Optional) list of values at different quantiles of the distribution calculated from the current snapshot. The quantiles must be strictly increasing.
flags	uint32		Flags that apply to this specific data point. See DataPointFlags for the available flags and their meaning.

SummaryDataPoint.ValueAtQuantile

Represents the value at a given quantile of a distribution.

To record Min and Max values following conventions are used: - The 1.0 quantile is equivalent to the maximum value observed. - The 0.0 quantile is equivalent to the minimum value observed.

See the following issue for more context: https://github.com/open-telemetry/opentelemetry-proto/issues/125

Field	Type	Label	Description
quantile	double		The quantile of a distribution. Must be in the interval [0.0, 1.0].
value	double		The value at the given quantile of a distribution. Quantile values must NOT be negative.

AggregationTemporality

AggregationTemporality defines how a metric aggregator reports aggregated values. It describes how those values relate to the time interval over which they are aggregated.

Name	Number	Description
AGGREGATION_TEMPORALITY_UNSPECIFIED	0	UNSPECIFIED is the default AggregationTemporality, it MUST not be used.
AGGREGATION_TEMPORALITY_DELTA	1	DELTA is an AggregationTemporality for a metric aggregator which reports changes since last report time. Successive metrics contain aggregation of values from continuous and non-overlapping intervals. The values for a DELTA metric are based only on the time interval associated with one measurement cycle. There is no dependency on previous measurements like is the case for CUMULATIVE metrics. For example, consider a system measuring the number of requests that it receives and reports the sum of these requests every second as a DELTA metric: 1. The system starts receiving at time=t_0. 2. A request is received, the system measures 1 request. 3. A request is received, the system measures 1 request. 4. A request is received, the system measures 1 request. 5. The 1 second collection cycle ends. A metric is exported for the number of requests received over the interval of time t_0 to t_0+1 with a value of 3. 6. A request is received, the system measures 1 request. 7. A request is received, the system measures 1 request. 8. The 1 second collection cycle ends. A metric is exported for the number of requests received over the interval of time t_0+1 to t_0+2 with a value of 2.
AGGREGATION_TEMPORALITY_CUMULATIVE	2	CUMULATIVE is an AggregationTemporality for a metric aggregator which reports changes since a fixed start time. This means that current values of a CUMULATIVE metric depend on all previous measurements since the start time. Because of this, the sender is required to retain this state in some form. If this state is lost or invalidated, the CUMULATIVE metric values MUST be reset and a new fixed start time following the last reported measurement time sent MUST be used. For example, consider a system measuring the number of requests that it receives and reports the sum of these requests every second as a CUMULATIVE metric: 1. The system starts receiving at time=t_0. 2. A request is received, the system measures 1 request. 3. A request is received, the system measures 1 request. 4. A request is received, the system measures 1 request. 5. The 1 second collection cycle ends. A metric is exported for the number of requests received over the interval of time t_0 to t_0+1 with a value of 3. 6. A request is received, the system measures 1 request. 7. A request is received, the system measures 1 request. 8. The 1 second collection cycle ends. A metric is exported for the number of requests received over the interval of time t_0 to t_0+2 with a value of 5. 9. The system experiences a fault and loses state. 10. The system recovers and resumes receiving at time=t_1. 11. A request is received, the system measures 1 request. 12. The 1 second collection cycle ends. A metric is exported for the number of requests received over the interval of time t_1 to t_0+1 with a value of 1. Note: Even though, when reporting changes since last report time, using CUMULATIVE is valid, it is not recommended. This may cause problems for systems that do not use start_time to determine when the aggregation value was reset (e.g. Prometheus).

DataPointFlags

DataPointFlags is defined as a protobuf 'uint32' type and is to be used as a bit-field representing 32 distinct boolean flags. Each flag defined in this enum is a bit-mask. To test the presence of a single flag in the flags of a data point, for example, use an expression like:

(point.flags & DATA_POINT_FLAGS_NO_RECORDED_VALUE_MASK) == DATA_POINT_FLAGS_NO_RECORDED_VALUE_MASK

Name	Number	Description
DATA_POINT_FLAGS_DO_NOT_USE	0	The zero value for the enum. Should not be used for comparisons. Instead use bitwise "and" with the appropriate mask as shown above.
DATA_POINT_FLAGS_NO_RECORDED_VALUE_MASK	1	This DataPoint is valid but has no recorded value. This value SHOULD be used to reflect explicitly missing data in a series, as for an equivalent to the Prometheus "staleness marker".

Resource

Resource information.

Field	Type	Label	Description
attributes	opentelemetry.proto.common.v1.KeyValue	repeated	Set of attributes that describe the resource. Attribute keys MUST be unique (it is not allowed to have more than one attribute with the same key).
dropped_attributes_count	uint32		dropped_attributes_count is the number of dropped attributes. If the value is 0, then no attributes were dropped.

ResourceSpans

A collection of ScopeSpans from a Resource.

Field	Type	Label	Description
resource	opentelemetry.proto.resource.v1.Resource		The resource for the spans in this message. If this field is not set then no resource info is known.
scope_spans	ScopeSpans	repeated	A list of ScopeSpans that originate from a resource.
schema_url	string		The Schema URL, if known. This is the identifier of the Schema that the resource data is recorded in. To learn more about Schema URL see https://opentelemetry.io/docs/specs/otel/schemas/#schema-url This schema_url applies to the data in the "resource" field. It does not apply to the data in the "scope_spans" field which have their own schema_url field.

ScopeSpans

A collection of Spans produced by an InstrumentationScope.

Field	Type	Label	Description
scope	opentelemetry.proto.common.v1.InstrumentationScope		The instrumentation scope information for the spans in this message. Semantically when InstrumentationScope isn't set, it is equivalent with an empty instrumentation scope name (unknown).
spans	Span	repeated	A list of Spans that originate from an instrumentation scope.
schema_url	string		The Schema URL, if known. This is the identifier of the Schema that the span data is recorded in. To learn more about Schema URL see https://opentelemetry.io/docs/specs/otel/schemas/#schema-url This schema_url applies to all spans and span events in the "spans" field.

Span

A Span represents a single operation performed by a single component of the system.

The next available field id is 17.

Field	Type	Label	Description
trace_id	bytes		A unique identifier for a trace. All spans from the same trace share the same trace_id. The ID is a 16-byte array. An ID with all zeroes OR of length other than 16 bytes is considered invalid (empty string in OTLP/JSON is zero-length and thus is also invalid). This field is required.
span_id	bytes		A unique identifier for a span within a trace, assigned when the span is created. The ID is an 8-byte array. An ID with all zeroes OR of length other than 8 bytes is considered invalid (empty string in OTLP/JSON is zero-length and thus is also invalid). This field is required.
trace_state	string		trace_state conveys information about request position in multiple distributed tracing graphs. It is a trace_state in w3c-trace-context format: https://www.w3.org/TR/trace-context/#tracestate-header See also https://github.com/w3c/distributed-tracing for more details about this field.
parent_span_id	bytes		The span_id of this span's parent span. If this is a root span, then this field must be empty. The ID is an 8-byte array.
flags	fixed32		Flags, a bit field. Bits 0-7 (8 least significant bits) are the trace flags as defined in W3C Trace Context specification. To read the 8-bit W3C trace flag, use flags & SPAN_FLAGS_TRACE_FLAGS_MASK. See https://www.w3.org/TR/trace-context-2/#trace-flags for the flag definitions. Bits 8 and 9 represent the 3 states of whether a span's parent is remote. The states are (unknown, is not remote, is remote). To read whether the value is known, use (flags & SPAN_FLAGS_CONTEXT_HAS_IS_REMOTE_MASK) != 0. To read whether the span is remote, use (flags & SPAN_FLAGS_CONTEXT_IS_REMOTE_MASK) != 0. When creating span messages, if the message is logically forwarded from another source with an equivalent flags fields (i.e., usually another OTLP span message), the field SHOULD be copied as-is. If creating from a source that does not have an equivalent flags field (such as a runtime representation of an OpenTelemetry span), the high 22 bits MUST be set to zero. Readers MUST NOT assume that bits 10-31 (22 most significant bits) will be zero. [Optional].
name	string		A description of the span's operation. For example, the name can be a qualified method name or a file name and a line number where the operation is called. A best practice is to use the same display name at the same call point in an application. This makes it easier to correlate spans in different traces. This field is semantically required to be set to non-empty string. Empty value is equivalent to an unknown span name. This field is required.
kind	Span.SpanKind		Distinguishes between spans generated in a particular context. For example, two spans with the same name may be distinguished using CLIENT (caller) and SERVER (callee) to identify queueing latency associated with the span.
start_time_unix_nano	fixed64		start_time_unix_nano is the start time of the span. On the client side, this is the time kept by the local machine where the span execution starts. On the server side, this is the time when the server's application handler starts running. Value is UNIX Epoch time in nanoseconds since 00:00:00 UTC on 1 January 1970. This field is semantically required and it is expected that end_time >= start_time.
end_time_unix_nano	fixed64		end_time_unix_nano is the end time of the span. On the client side, this is the time kept by the local machine where the span execution ends. On the server side, this is the time when the server application handler stops running. Value is UNIX Epoch time in nanoseconds since 00:00:00 UTC on 1 January 1970. This field is semantically required and it is expected that end_time >= start_time.
attributes	opentelemetry.proto.common.v1.KeyValue	repeated	attributes is a collection of key/value pairs. Note, global attributes like server name can be set using the resource API. Examples of attributes: "/http/user_agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36" "/http/server_latency": 300 "example.com/myattribute": true "example.com/score": 10.239 The OpenTelemetry API specification further restricts the allowed value types: https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/common/README.md#attribute Attribute keys MUST be unique (it is not allowed to have more than one attribute with the same key).
dropped_attributes_count	uint32		dropped_attributes_count is the number of attributes that were discarded. Attributes can be discarded because their keys are too long or because there are too many attributes. If this value is 0, then no attributes were dropped.
events	Span.Event	repeated	events is a collection of Event items.
dropped_events_count	uint32		dropped_events_count is the number of dropped events. If the value is 0, then no events were dropped.
links	Span.Link	repeated	links is a collection of Links, which are references from this span to a span in the same or different trace.
dropped_links_count	uint32		dropped_links_count is the number of dropped links after the maximum size was enforced. If this value is 0, then no links were dropped.
status	Status		An optional final status for this span. Semantically when Status isn't set, it means span's status code is unset, i.e. assume STATUS_CODE_UNSET (code = 0).

Span.Event

Event is a time-stamped annotation of the span, consisting of user-supplied text description and key-value pairs.

Field	Type	Label	Description
time_unix_nano	fixed64		time_unix_nano is the time the event occurred.
name	string		name of the event. This field is semantically required to be set to non-empty string.
attributes	opentelemetry.proto.common.v1.KeyValue	repeated	attributes is a collection of attribute key/value pairs on the event. Attribute keys MUST be unique (it is not allowed to have more than one attribute with the same key).
dropped_attributes_count	uint32		dropped_attributes_count is the number of dropped attributes. If the value is 0, then no attributes were dropped.

Span.Link

A pointer from the current span to another span in the same trace or in a different trace. For example, this can be used in batching operations, where a single batch handler processes multiple requests from different traces or when the handler receives a request from a different project.

Field	Type	Label	Description
trace_id	bytes		A unique identifier of a trace that this linked span is part of. The ID is a 16-byte array.
span_id	bytes		A unique identifier for the linked span. The ID is an 8-byte array.
trace_state	string		The trace_state associated with the link.
attributes	opentelemetry.proto.common.v1.KeyValue	repeated	attributes is a collection of attribute key/value pairs on the link. Attribute keys MUST be unique (it is not allowed to have more than one attribute with the same key).
dropped_attributes_count	uint32		dropped_attributes_count is the number of dropped attributes. If the value is 0, then no attributes were dropped.
flags	fixed32		Flags, a bit field. Bits 0-7 (8 least significant bits) are the trace flags as defined in W3C Trace Context specification. To read the 8-bit W3C trace flag, use flags & SPAN_FLAGS_TRACE_FLAGS_MASK. See https://www.w3.org/TR/trace-context-2/#trace-flags for the flag definitions. Bits 8 and 9 represent the 3 states of whether the link is remote. The states are (unknown, is not remote, is remote). To read whether the value is known, use (flags & SPAN_FLAGS_CONTEXT_HAS_IS_REMOTE_MASK) != 0. To read whether the link is remote, use (flags & SPAN_FLAGS_CONTEXT_IS_REMOTE_MASK) != 0. Readers MUST NOT assume that bits 10-31 (22 most significant bits) will be zero. When creating new spans, bits 10-31 (most-significant 22-bits) MUST be zero. [Optional].

Status

The Status type defines a logical error model that is suitable for different programming environments, including REST APIs and RPC APIs.

Field	Type	Label	Description
message	string		A developer-facing human readable error message.
code	Status.StatusCode		The status code.

TracesData

TracesData represents the traces data that can be stored in a persistent storage, OR can be embedded by other protocols that transfer OTLP traces data but do not implement the OTLP protocol.

The main difference between this message and collector protocol is that in this message there will not be any "control" or "metadata" specific to OTLP protocol.

When new fields are added into this message, the OTLP request MUST be updated as well.

Field	Type	Label	Description
resource_spans	ResourceSpans	repeated	An array of ResourceSpans. For data coming from a single resource this array will typically contain one element. Intermediary nodes that receive data from multiple origins typically batch the data before forwarding further and in that case this array will contain multiple elements.

Span.SpanKind

SpanKind is the type of span. Can be used to specify additional relationships between spans in addition to a parent/child relationship.

Name	Number	Description
SPAN_KIND_UNSPECIFIED	0	Unspecified. Do NOT use as default. Implementations MAY assume SpanKind to be INTERNAL when receiving UNSPECIFIED.
SPAN_KIND_INTERNAL	1	Indicates that the span represents an internal operation within an application, as opposed to an operation happening at the boundaries. Default value.
SPAN_KIND_SERVER	2	Indicates that the span covers server-side handling of an RPC or other remote network request.
SPAN_KIND_CLIENT	3	Indicates that the span describes a request to some remote service.
SPAN_KIND_PRODUCER	4	Indicates that the span describes a producer sending a message to a broker. Unlike CLIENT and SERVER, there is often no direct critical path latency relationship between producer and consumer spans. A PRODUCER span ends when the message was accepted by the broker while the logical processing of the message might span a much longer time.
SPAN_KIND_CONSUMER	5	Indicates that the span describes consumer receiving a message from a broker. Like the PRODUCER kind, there is often no direct critical path latency relationship between producer and consumer spans.

SpanFlags

SpanFlags represents constants used to interpret the Span.flags field, which is protobuf 'fixed32' type and is to be used as bit-fields. Each non-zero value defined in this enum is a bit-mask. To extract the bit-field, for example, use an expression like:

(span.flags & SPAN_FLAGS_TRACE_FLAGS_MASK)

See https://www.w3.org/TR/trace-context-2/#trace-flags for the flag definitions.

Note that Span flags were introduced in version 1.1 of the OpenTelemetry protocol. Older Span producers do not set this field, consequently consumers should not rely on the absence of a particular flag bit to indicate the presence of a particular feature.

Name	Number	Description
SPAN_FLAGS_DO_NOT_USE	0	The zero value for the enum. Should not be used for comparisons. Instead use bitwise "and" with the appropriate mask as shown above.
SPAN_FLAGS_TRACE_FLAGS_MASK	255	Bits 0-7 are used for trace flags.
SPAN_FLAGS_CONTEXT_HAS_IS_REMOTE_MASK	256	Bits 8 and 9 are used to indicate that the parent span or link span is remote. Bit 8 (HAS_IS_REMOTE) indicates whether the value is known. Bit 9 (IS_REMOTE) indicates whether the span or link is remote.
SPAN_FLAGS_CONTEXT_IS_REMOTE_MASK	512

Status.StatusCode

For the semantics of status codes see https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/api.md#set-status

Name	Number	Description
STATUS_CODE_UNSET	0	The default status.
STATUS_CODE_OK	1	The Span has been validated by an Application developer or Operator to have completed successfully.
STATUS_CODE_ERROR	2	The Span contains an error.

Scalar Value Types

.proto Type	Notes	C++	Java	Python	Go	C#	PHP	Ruby
double		double	double	float	float64	double	float	Float
float		float	float	float	float32	float	float	Float
int32	Uses variable-length encoding. Inefficient for encoding negative numbers – if your field is likely to have negative values, use sint32 instead.	int32	int	int	int32	int	integer	Bignum or Fixnum (as required)
int64	Uses variable-length encoding. Inefficient for encoding negative numbers – if your field is likely to have negative values, use sint64 instead.	int64	long	int/long	int64	long	integer/string	Bignum
uint32	Uses variable-length encoding.	uint32	int	int/long	uint32	uint	integer	Bignum or Fixnum (as required)
uint64	Uses variable-length encoding.	uint64	long	int/long	uint64	ulong	integer/string	Bignum or Fixnum (as required)
sint32	Uses variable-length encoding. Signed int value. These more efficiently encode negative numbers than regular int32s.	int32	int	int	int32	int	integer	Bignum or Fixnum (as required)
sint64	Uses variable-length encoding. Signed int value. These more efficiently encode negative numbers than regular int64s.	int64	long	int/long	int64	long	integer/string	Bignum
fixed32	Always four bytes. More efficient than uint32 if values are often greater than 2^28.	uint32	int	int	uint32	uint	integer	Bignum or Fixnum (as required)
fixed64	Always eight bytes. More efficient than uint64 if values are often greater than 2^56.	uint64	long	int/long	uint64	ulong	integer/string	Bignum
sfixed32	Always four bytes.	int32	int	int	int32	int	integer	Bignum or Fixnum (as required)
sfixed64	Always eight bytes.	int64	long	int/long	int64	long	integer/string	Bignum
bool		bool	boolean	boolean	bool	bool	boolean	TrueClass/FalseClass
string	A string must always contain UTF-8 encoded or 7-bit ASCII text.	string	String	str/unicode	string	string	string	String (UTF-8)
bytes	May contain any arbitrary sequence of bytes.	string	ByteString	str	[]byte	ByteString	string	String (ASCII-8BIT)