You can apply configuration settings in the following ways,
with environment variables taking precedence over App.config or Web.config file:
-
Environment variables
Environment variables are the main way to configure the settings.
-
App.configorWeb.configfileFor an application running on .NET Framework, you can use a web configuration file (
web.config) or an application configuration file (app.config) to configure theOTEL_*settings.⚠️ Only settings starting withOTEL_can be set usingApp.configorWeb.config. However, the following settings are not supported:OTEL_DOTNET_AUTO_HOMEOTEL_DOTNET_AUTO_EXCLUDE_PROCESSESOTEL_DOTNET_AUTO_FAIL_FAST_ENABLEDOTEL_DOTNET_AUTO_[TRACES|METRICS|LOGS]_INSTRUMENTATION_ENABLEDOTEL_DOTNET_AUTO_[TRACES|METRICS|LOGS]_{INSTRUMENTATION_ID}_INSTRUMENTATION_ENABLEDOTEL_DOTNET_AUTO_LOG_DIRECTORYOTEL_LOG_LEVELOTEL_DOTNET_AUTO_NETFX_REDIRECT_ENABLED
Example with
OTEL_SERVICE_NAMEsetting:<configuration> <appSettings> <add key="OTEL_SERVICE_NAME" value="my-service-name" /> </appSettings> </configuration>
-
Service name automatic detection
If no service name is explicitly configured one will be generated for you. This can be helpful in some circumstances.
- If the application is hosted on IIS in .NET Framework this will be
SiteName\VirtualPathex:MySite\MyApp - If that is not the case it will use the name of the application entry Assembly.
- If the application is hosted on IIS in .NET Framework this will be
By default we recommend using environment variables for configuration. However, if given setting supports it, then:
- use
Web.configfor configuring an ASP.NET application (.NET Framework), - use
App.configfor configuring a Windows Service (.NET Framework).
| Environment variable | Description | Default value | Status |
|---|---|---|---|
OTEL_DOTNET_AUTO_HOME |
Installation location. | Experimental | |
OTEL_DOTNET_AUTO_EXCLUDE_PROCESSES |
Names of the executable files that the profiler cannot instrument. Supports multiple comma-separated values, for example: ReservedProcess.exe,powershell.exe. If unset, the profiler attaches to all processes by default. [1][2] |
Experimental | |
OTEL_DOTNET_AUTO_FAIL_FAST_ENABLED |
Enables possibility to fail process when automatic instrumentation cannot be executed. It is designed for debugging purposes. It should not be used in production environment. [1] | false |
Experimental |
OTEL_DOTNET_AUTO_LOGGER |
AutoInstrumentation diagnostic logs sink. (supported values: none,file,console) |
file |
Experimental |
OTEL_LOG_LEVEL |
SDK log level. (supported values: none,error,warn,info,debug) |
info |
Stable |
[1] If OTEL_DOTNET_AUTO_FAIL_FAST_ENABLED is set to true then processes
excluded from instrumentation by OTEL_DOTNET_AUTO_EXCLUDE_PROCESSES will fail
instead of silently continue.
[2] Notice that applications launched via dotnet MyApp.dll have process
name dotnet or dotnet.exe.
A resource is the immutable representation of the entity producing the telemetry. See Resource semantic conventions for more details.
| Environment variable | Description | Default value | Status |
|---|---|---|---|
OTEL_RESOURCE_ATTRIBUTES |
Key-value pairs to be used as resource attributes. See Resource SDK for more details. | See Resource semantic conventions for details. | Stable |
OTEL_SERVICE_NAME |
Sets the value of the service.name resource attribute. If service.name is provided in OTEL_RESOURCE_ATTRIBUTES, the value of OTEL_SERVICE_NAME takes precedence. |
See Service name automatic detection under Configuration method section. | Stable |
| Environment variable | Description | Default value | Status |
|---|---|---|---|
OTEL_DOTNET_AUTO_RESOURCE_DETECTOR_ENABLED |
Enables all resource detectors. | true |
Experimental |
OTEL_DOTNET_AUTO_{0}_RESOURCE_DETECTOR_ENABLED |
Configuration pattern for enabling a specific resource detector, where {0} is the uppercase id of the resource detector you want to enable. Overrides OTEL_DOTNET_AUTO_RESOURCE_DETECTOR_ENABLED. |
true |
Experimental |
The following resource detectors are included and enabled by default:
| ID | Description | Documentation | Status |
|---|---|---|---|
AZUREAPPSERVICE |
Azure App Service detector | Azure resource detector documentation | Experimental |
CONTAINER |
Container detector | Container resource detector documentation Not supported on .NET Framework | Experimental |
HOST |
Host detector | Host resource detector documentation | Experimental |
OPERATINGSYSTEM |
Operating System detector | Operating System resource detector documentation | Experimental |
PROCESS |
Process detector | Process resource detector documentation | Experimental |
PROCESSRUNTIME |
Process Runtime detector | Process Runtime resource detector documentation | Experimental |
All instrumentations are enabled by default for all signal types (traces, metrics, and logs).
You can disable all instrumentations for a specific signal type by setting
the OTEL_DOTNET_AUTO_{SIGNAL}_INSTRUMENTATION_ENABLED
environment variable to false.
For a more granular approach, you can disable specific instrumentations
for a given signal type by setting
the OTEL_DOTNET_AUTO_{SIGNAL}_{0}_INSTRUMENTATION_ENABLED
environment variable to false, where {SIGNAL} is the type of signal,
for example TRACES, and {0} is the case-sensitive name of the instrumentation.
| Environment variable | Description | Default value | Status |
|---|---|---|---|
OTEL_DOTNET_AUTO_INSTRUMENTATION_ENABLED |
Enables all instrumentations. | true |
Experimental |
OTEL_DOTNET_AUTO_TRACES_INSTRUMENTATION_ENABLED |
Enables all trace instrumentations. Overrides OTEL_DOTNET_AUTO_INSTRUMENTATION_ENABLED. |
Inherited from the current value of OTEL_DOTNET_AUTO_INSTRUMENTATION_ENABLED |
Experimental |
OTEL_DOTNET_AUTO_TRACES_{0}_INSTRUMENTATION_ENABLED |
Configuration pattern for enabling a specific trace instrumentation, where {0} is the uppercase id of the instrumentation you want to enable. Overrides OTEL_DOTNET_AUTO_TRACES_INSTRUMENTATION_ENABLED. |
Inherited from the current value of OTEL_DOTNET_AUTO_TRACES_INSTRUMENTATION_ENABLED |
Experimental |
OTEL_DOTNET_AUTO_METRICS_INSTRUMENTATION_ENABLED |
Disables all metric instrumentations. Overrides OTEL_DOTNET_AUTO_INSTRUMENTATION_ENABLED. |
Inherited from the current value of OTEL_DOTNET_AUTO_INSTRUMENTATION_ENABLED |
Experimental |
OTEL_DOTNET_AUTO_METRICS_{0}_INSTRUMENTATION_ENABLED |
Configuration pattern for enabling a specific metric instrumentation, where {0} is the uppercase id of the instrumentation you want to enable. Overrides OTEL_DOTNET_AUTO_METRICS_INSTRUMENTATION_ENABLED. |
Inherited from the current value of OTEL_DOTNET_AUTO_METRICS_INSTRUMENTATION_ENABLED |
Experimental |
OTEL_DOTNET_AUTO_LOGS_INSTRUMENTATION_ENABLED |
Disables all log instrumentations. Overrides OTEL_DOTNET_AUTO_INSTRUMENTATION_ENABLED. |
Inherited from the current value of OTEL_DOTNET_AUTO_INSTRUMENTATION_ENABLED |
Experimental |
OTEL_DOTNET_AUTO_LOGS_{0}_INSTRUMENTATION_ENABLED |
Configuration pattern for enabling a specific log instrumentation, where {0} is the uppercase id of the instrumentation you want to enable. Overrides OTEL_DOTNET_AUTO_LOGS_INSTRUMENTATION_ENABLED. |
Inherited from the current value of OTEL_DOTNET_AUTO_LOGS_INSTRUMENTATION_ENABLED |
Experimental |
Status: Mixed. Traces are stable, but particular instrumentation are in Experimental status due to lack of stable semantic convention.
| ID | Instrumented library | Supported versions | Instrumentation type | Status |
|---|---|---|---|---|
ASPNET |
ASP.NET (.NET Framework) MVC / WebApi [1] Not supported on .NET | * [2] | source & bytecode | Experimental |
ASPNETCORE |
ASP.NET Core Not supported on .NET Framework | * | source | Experimental |
AZURE |
Azure SDK | [3] | source | Experimental |
ELASTICSEARCH |
Elastic.Clients.Elasticsearch | * [4] | source | Experimental |
ELASTICTRANSPORT |
Elastic.Transport | ≥0.4.16 | source | Experimental |
ENTITYFRAMEWORKCORE |
Microsoft.EntityFrameworkCore Not supported on .NET Framework | ≥6.0.12 | source | Experimental |
GRAPHQL |
GraphQL Not supported on .NET Framework | ≥7.5.0 | source | Experimental |
GRPCNETCLIENT |
Grpc.Net.Client | ≥2.52.0 & < 3.0.0 | source | Experimental |
HTTPCLIENT |
System.Net.Http.HttpClient and System.Net.HttpWebRequest | * | source | Experimental |
KAFKA |
Confluent.Kafka | ≥1.4.0 & < 3.0.0 [5] | bytecode | Experimental |
MASSTRANSIT |
MassTransit Not supported on .NET Framework | ≥8.0.0 | source | Experimental |
MONGODB |
MongoDB.Driver.Core | ≥2.28.0 & < 3.0.0 | source & bytecode | Experimental |
MYSQLCONNECTOR |
MySqlConnector | ≥2.0.0 | source | Experimental |
MYSQLDATA |
MySql.Data Not supported on .NET Framework | ≥8.1.0 | source | Experimental |
NPGSQL |
Npgsql | ≥6.0.0 | source | Experimental |
NSERVICEBUS |
NServiceBus | ≥8.0.0 & < 10.0.0 | source & bytecode | Experimental |
ORACLEMDA |
Oracle.ManagedDataAccess.Core and Oracle.ManagedDataAccess Not supported on ARM64 | ≥23.4.0 | source | Experimental |
RABBITMQ |
RabbitMQ.Client | ≥6.0.0 | source or bytecode [6] | Experimental |
QUARTZ |
Quartz Not supported on .NET Framework 4.7.1 and older | ≥3.4.0 | source | Experimental |
SQLCLIENT |
Microsoft.Data.SqlClient, System.Data.SqlClient [7] and System.Data (shipped with .NET Framework) |
* [8] | source | Experimental |
STACKEXCHANGEREDIS |
StackExchange.Redis Not supported on .NET Framework | ≥2.6.122 & < 3.0.0 | source & bytecode | Experimental |
WCFCLIENT |
WCF | * | source & bytecode | Experimental |
WCFSERVICE |
WCF Not supported on .NET. | * | source & bytecode | Experimental |
[1]: Only integrated pipeline mode is supported.
[2]: ASP.NET (.NET Framework) MVC / WebApi is not supported on ARM64.
[3]: Azure. prefixed packages, released after October 1, 2021.
[4]: Elastic.Clients.Elasticsearch version ≥8.0.0 and <8.10.0.
Version ≥8.10.0 is supported by Elastic.Transport instrumentation.
[5]: Confluent.Kafka is supported from version ≥1.8.2 on ARM64.
[6]: RabbitMq.Client needs bytecode instrumentation only for 6.. versions
7.0.0+ uses only source instrumentation.
[7]: System.Data.SqlClient is deprecated.
[8]: Microsoft.Data.SqlClient v3.* is not supported on .NET Framework,
due to issue.
System.Data.SqlClient is supported from version 4.8.5.
Status: Mixed. Metrics are stable, but particular instrumentation are in Experimental status due to lack of stable semantic convention.
| ID | Instrumented library | Documentation | Supported versions | Instrumentation type | Status |
|---|---|---|---|---|---|
ASPNET |
ASP.NET Framework [1] Not supported on .NET | ASP.NET metrics | * | source & bytecode | Experimental |
ASPNETCORE |
ASP.NET Core [2] Not supported on .NET Framework | ASP.NET Core metrics | * | source | Experimental |
HTTPCLIENT |
System.Net.Http.HttpClient and System.Net.HttpWebRequest | HttpClient metrics | * | source | Experimental |
NETRUNTIME |
OpenTelemetry.Instrumentation.Runtime | Runtime metrics | * | source | Experimental |
PROCESS |
OpenTelemetry.Instrumentation.Process | Process metrics | * | source | Experimental |
NSERVICEBUS |
NServiceBus | NServiceBus metrics | ≥8.0.0 & < 10.0.0 | source & bytecode | Experimental |
[1]: The ASP.NET metrics are generated only if the AspNet trace instrumentation
is also enabled.
[2]: This instrumentation automatically enables the
Microsoft.AspNetCore.Hosting.HttpRequestIn spans.
Status: Experimental.
| ID | Instrumented library | Supported versions | Instrumentation type | Status |
|---|---|---|---|---|
ILOGGER |
Microsoft.Extensions.Logging Not supported on .NET Framework | ≥8.0.0 | bytecode or source [1] | Experimental |
[1]: For ASP.NET Core applications, the LoggingBuilder instrumentation
can be enabled without using the .NET CLR Profiler by setting
the ASPNETCORE_HOSTINGSTARTUPASSEMBLIES environment variable to
OpenTelemetry.AutoInstrumentation.AspNetCoreBootstrapper.
| Environment variable | Description | Default value | Status |
|---|---|---|---|
OTEL_DOTNET_AUTO_ENTITYFRAMEWORKCORE_SET_DBSTATEMENT_FOR_TEXT |
Whether the Entity Framework Core instrumentation can pass SQL statements through the db.statement attribute. Queries might contain sensitive information. If set to false, db.statement is recorded only for executing stored procedures. |
false |
Experimental |
OTEL_DOTNET_AUTO_GRAPHQL_SET_DOCUMENT |
Whether the GraphQL instrumentation can pass raw queries through the graphql.document attribute. Queries might contain sensitive information. |
false |
Experimental |
OTEL_DOTNET_AUTO_ORACLEMDA_SET_DBSTATEMENT_FOR_TEXT |
Whether the Oracle Client instrumentation can pass SQL statements through the db.statement attribute. Queries might contain sensitive information. If set to false, db.statement is recorded only for executing stored procedures. |
false |
Experimental |
OTEL_DOTNET_AUTO_SQLCLIENT_SET_DBSTATEMENT_FOR_TEXT |
Whether the SQL Client instrumentation can pass SQL statements through the db.statement attribute. Queries might contain sensitive information. If set to false, db.statement is recorded only for executing stored procedures. Not supported on .NET Framework for System.Data.SqlClient. |
false |
Experimental |
OTEL_DOTNET_AUTO_TRACES_ASPNET_INSTRUMENTATION_CAPTURE_REQUEST_HEADERS |
A comma-separated list of HTTP header names. ASP.NET instrumentations will capture HTTP request header values for all configured header names. | Experimental | |
OTEL_DOTNET_AUTO_TRACES_ASPNET_INSTRUMENTATION_CAPTURE_RESPONSE_HEADERS |
A comma-separated list of HTTP header names. ASP.NET instrumentations will capture HTTP response header values for all configured header names. Not supported on IIS Classic mode. | Experimental | |
OTEL_DOTNET_AUTO_TRACES_ASPNETCORE_INSTRUMENTATION_CAPTURE_REQUEST_HEADERS |
A comma-separated list of HTTP header names. ASP.NET Core instrumentations will capture HTTP request header values for all configured header names. | Experimental | |
OTEL_DOTNET_AUTO_TRACES_ASPNETCORE_INSTRUMENTATION_CAPTURE_RESPONSE_HEADERS |
A comma-separated list of HTTP header names. ASP.NET Core instrumentations will capture HTTP response header values for all configured header names. | Experimental | |
OTEL_DOTNET_AUTO_TRACES_GRPCNETCLIENT_INSTRUMENTATION_CAPTURE_REQUEST_METADATA |
A comma-separated list of gRPC metadata names. Grpc.Net.Client instrumentations will capture gRPC request metadata values for all configured metadata names. | Experimental | |
OTEL_DOTNET_AUTO_TRACES_GRPCNETCLIENT_INSTRUMENTATION_CAPTURE_RESPONSE_METADATA |
A comma-separated list of gRPC metadata names. Grpc.Net.Client instrumentations will capture gRPC response metadata values for all configured metadata names. | Experimental | |
OTEL_DOTNET_AUTO_TRACES_HTTP_INSTRUMENTATION_CAPTURE_REQUEST_HEADERS |
A comma-separated list of HTTP header names. HTTP Client instrumentations will capture HTTP request header values for all configured header names. | Experimental | |
OTEL_DOTNET_AUTO_TRACES_HTTP_INSTRUMENTATION_CAPTURE_RESPONSE_HEADERS |
A comma-separated list of HTTP header names. HTTP Client instrumentations will capture HTTP response header values for all configured header names. | Experimental | |
OTEL_DOTNET_EXPERIMENTAL_ASPNETCORE_DISABLE_URL_QUERY_REDACTION |
Whether the ASP.NET Core instrumentation turns off redaction of the url.query attribute value. |
false |
Experimental |
OTEL_DOTNET_EXPERIMENTAL_HTTPCLIENT_DISABLE_URL_QUERY_REDACTION |
Whether the HTTP client instrumentation turns off redaction of the url.full attribute value. |
false |
Experimental |
OTEL_DOTNET_EXPERIMENTAL_ASPNET_DISABLE_URL_QUERY_REDACTION |
Whether the ASP.NET instrumentation turns off redaction of the url.query attribute value. |
false |
Experimental |
Propagators allow applications to share context. See the OpenTelemetry specification for more details.
| Environment variable | Description | Default value |
|---|---|---|
OTEL_PROPAGATORS |
Comma-separated list of propagators. Supported options: tracecontext, baggage, b3multi, b3. See the OpenTelemetry specification for more details. |
tracecontext,baggage |
Samplers let you control potential noise and overhead introduced by OpenTelemetry instrumentation by selecting which traces you want to collect and export. See the OpenTelemetry specification for more details.
| Environment variable | Description | Default value | Status |
|---|---|---|---|
OTEL_TRACES_SAMPLER |
Sampler to be used for traces [1] | parentbased_always_on |
Stable |
OTEL_TRACES_SAMPLER_ARG |
String value to be used as the sampler argument [2] | Stable |
[1]: Supported values are:
always_on,always_off,traceidratio,parentbased_always_on,parentbased_always_off,parentbased_traceidratio.
[2]: For traceidratio and parentbased_traceidratio samplers:
Sampling probability, a number in the [0..1] range, e.g. "0.25".
Default is 1.0.
Exporters output the telemetry.
| Environment variable | Description | Default value | Status |
|---|---|---|---|
OTEL_TRACES_EXPORTER |
Comma-separated list of exporters. Supported options: otlp, zipkin, console, none. See the OpenTelemetry specification for more details. |
otlp |
Stable |
OTEL_METRICS_EXPORTER |
Comma-separated list of exporters. Supported options: otlp, prometheus, console, none. See the OpenTelemetry specification for more details. |
otlp |
Stable |
OTEL_LOGS_EXPORTER |
Comma-separated list of exporters. Supported options: otlp, console, none. See the OpenTelemetry specification for more details. |
otlp |
Stable |
| Environment variable | Description | Default value | Status |
|---|---|---|---|
OTEL_BSP_SCHEDULE_DELAY |
Delay interval (in milliseconds) between two consecutive exports. | 5000 |
Stable |
OTEL_BSP_EXPORT_TIMEOUT |
Maximum allowed time (in milliseconds) to export data | 30000 |
Stable |
OTEL_BSP_MAX_QUEUE_SIZE |
Maximum queue size. | 2048 |
Stable |
OTEL_BSP_MAX_EXPORT_BATCH_SIZE |
Maximum batch size. Must be less than or equal to OTEL_BSP_MAX_QUEUE_SIZE. |
512 |
Stable |
| Environment variable | Description | Default value | Status |
|---|---|---|---|
OTEL_METRIC_EXPORT_INTERVAL |
The time interval (in milliseconds) between the start of two export attempts. | 60000 for OTLP exporter, 10000 for console exporter |
Stable |
OTEL_METRIC_EXPORT_TIMEOUT |
Maximum allowed time (in milliseconds) to export data. | 30000 for OTLP exporter, none for console exporter |
Stable |
| Environment variable | Description | Default value | Status |
|---|---|---|---|
OTEL_DOTNET_AUTO_LOGS_INCLUDE_FORMATTED_MESSAGE |
Whether the formatted log message should be set or not. | false |
Experimental |
Status: Stable
To enable the OTLP exporter, set the OTEL_TRACES_EXPORTER/OTEL_METRICS_EXPORTER/OTEL_LOGS_EXPORTER
environment variable to otlp.
To customize the OTLP exporter using environment variables, see the OTLP exporter documentation. Important environment variables include:
| Environment variable | Description | Default value | Status |
|---|---|---|---|
OTEL_EXPORTER_OTLP_ENDPOINT |
Target endpoint for the OTLP exporter. See the OpenTelemetry specification for more details. | http/protobuf: http://localhost:4318, grpc: http://localhost:4317 |
Stable |
OTEL_EXPORTER_OTLP_TRACES_ENDPOINT |
Equivalent to OTEL_EXPORTER_OTLP_ENDPOINT, but applies only to traces. |
http/protobuf: http://localhost:4318/v1/traces, grpc: http://localhost:4317 |
Stable |
OTEL_EXPORTER_OTLP_METRICS_ENDPOINT |
Equivalent to OTEL_EXPORTER_OTLP_ENDPOINT, but applies only to metrics. |
http/protobuf: http://localhost:4318/v1/metrics, grpc: http://localhost:4317 |
Stable |
OTEL_EXPORTER_OTLP_LOGS_ENDPOINT |
Equivalent to OTEL_EXPORTER_OTLP_ENDPOINT, but applies only to logs. |
http/protobuf: http://localhost:4318/v1/logs, grpc: http://localhost:4317 |
Stable |
OTEL_EXPORTER_OTLP_PROTOCOL |
OTLP exporter transport protocol. Supported values are grpc, http/protobuf. [1] |
http/protobuf |
Stable |
OTEL_EXPORTER_OTLP_TRACES_PROTOCOL |
Equivalent to OTEL_EXPORTER_OTLP_PROTOCOL, but applies only to traces. |
http/protobuf |
Stable |
OTEL_EXPORTER_OTLP_METRICS_PROTOCOL |
Equivalent to OTEL_EXPORTER_OTLP_PROTOCOL, but applies only to metrics. |
http/protobuf |
Stable |
OTEL_EXPORTER_OTLP_LOGS_PROTOCOL |
Equivalent to OTEL_EXPORTER_OTLP_PROTOCOL, but applies only to logs. |
http/protobuf |
Stable |
OTEL_EXPORTER_OTLP_TIMEOUT |
The max waiting time (in milliseconds) for the backend to process each batch. | 10000 (10s) |
Stable |
OTEL_EXPORTER_OTLP_TRACES_TIMEOUT |
Equivalent to OTEL_EXPORTER_OTLP_TIMEOUT, but applies only to traces. |
10000 (10s) |
Stable |
OTEL_EXPORTER_OTLP_METRICS_TIMEOUT |
Equivalent to OTEL_EXPORTER_OTLP_TIMEOUT, but applies only to metrics. |
10000 (10s) |
Stable |
OTEL_EXPORTER_OTLP_LOGS_TIMEOUT |
Equivalent to OTEL_EXPORTER_OTLP_TIMEOUT, but applies only to logs. |
10000 (10s) |
Stable |
OTEL_EXPORTER_OTLP_HEADERS |
Comma-separated list of additional HTTP headers sent with each export, for example: Authorization=secret,X-Key=Value. |
Stable | |
OTEL_EXPORTER_OTLP_TRACES_HEADERS |
Equivalent to OTEL_EXPORTER_OTLP_HEADERS, but applies only to traces. |
Stable | |
OTEL_EXPORTER_OTLP_METRICS_HEADERS |
Equivalent to OTEL_EXPORTER_OTLP_HEADERS, but applies only to metrics. |
Stable | |
OTEL_EXPORTER_OTLP_LOGS_HEADERS |
Equivalent to OTEL_EXPORTER_OTLP_HEADERS, but applies only to logs. |
Stable | |
OTEL_ATTRIBUTE_VALUE_LENGTH_LIMIT |
Maximum allowed attribute value size. | none | Stable |
OTEL_ATTRIBUTE_COUNT_LIMIT |
Maximum allowed span attribute count. | 128 | Stable |
OTEL_SPAN_ATTRIBUTE_VALUE_LENGTH_LIMIT |
Maximum allowed attribute value size. Not applicable for metrics.. | none | Stable |
OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT |
Maximum allowed span attribute count. Not applicable for metrics.. | 128 | Stable |
OTEL_SPAN_EVENT_COUNT_LIMIT |
Maximum allowed span event count. | 128 | Stable |
OTEL_SPAN_LINK_COUNT_LIMIT |
Maximum allowed span link count. | 128 | Stable |
OTEL_EVENT_ATTRIBUTE_COUNT_LIMIT |
Maximum allowed attribute per span event count. | 128 | Stable |
OTEL_LINK_ATTRIBUTE_COUNT_LIMIT |
Maximum allowed attribute per span link count. | 128 | Stable |
OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE |
The aggregation temporality to use on the basis of instrument kind. [2] | cumulative |
Stable |
[1]: Considerations on the OTEL_EXPORTER_OTLP_PROTOCOL:
- The OpenTelemetry .NET Automatic Instrumentation defaults to
http/protobuf, which differs from the OpenTelemetry .NET SDK default value ofgrpc. - On .NET 8 and higher, the application must reference
Grpc.Net.Clientto use thegrpcOTLP exporter protocol. For example, by adding<PackageReference Include="Grpc.Net.Client" Version="2.65.0" />to the.csprojfile. - On .NET Framework, the
grpcOTLP exporter protocol is not supported.
[2]: The recognized (case-insensitive) values for OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE are:
Cumulative: Choose cumulative aggregation temporality for all instrument kinds.Delta: Choose Delta aggregation temporality for Counter, Asynchronous Counter and Histogram instrument kinds, choose Cumulative aggregation for UpDownCounter and Asynchronous UpDownCounter instrument kinds.LowMemory: This configuration uses Delta aggregation temporality for Synchronous Counter and Histogram and uses Cumulative aggregation temporality for Synchronous UpDownCounter, Asynchronous Counter, and Asynchronous UpDownCounter instrument kinds.⚠️ This value known from specification is not supported.
Status: Experimental
Warning
Do NOT use in production.
Prometheus exporter is intended for the inner dev loop.
Production environments can use a combination of OTLP exporter
with OpenTelemetry Collector
having otlp receiver
and prometheus exporter.
To enable the Prometheus exporter, set the OTEL_METRICS_EXPORTER environment
variable to prometheus.
The exporter exposes the metrics HTTP endpoint on http://localhost:9464/metrics
and it caches the responses for 300 milliseconds.
See the Prometheus Exporter HttpListener documentation. to learn more.
Status: Stable
To enable the Zipkin exporter, set the OTEL_TRACES_EXPORTER environment
variable to zipkin.
To customize the Zipkin exporter using environment variables, see the Zipkin exporter documentation. Important environment variables include:
| Environment variable | Description | Default value | Status |
|---|---|---|---|
OTEL_EXPORTER_ZIPKIN_ENDPOINT |
Zipkin URL | http://localhost:9411/api/v2/spans |
Stable |
| Environment variable | Description | Default value | Status |
|---|---|---|---|
OTEL_DOTNET_AUTO_TRACES_ENABLED |
Enables traces. | true |
Experimental |
OTEL_DOTNET_AUTO_OPENTRACING_ENABLED |
Enables OpenTracing tracer. | false |
Experimental |
OTEL_DOTNET_AUTO_LOGS_ENABLED |
Enables logs. | true |
Experimental |
OTEL_DOTNET_AUTO_METRICS_ENABLED |
Enables metrics. | true |
Experimental |
OTEL_DOTNET_AUTO_NETFX_REDIRECT_ENABLED |
Enables automatic redirection of the assemblies used by the automatic instrumentation on the .NET Framework. | true |
Experimental |
OTEL_DOTNET_AUTO_TRACES_ADDITIONAL_SOURCES |
Comma-separated list of additional System.Diagnostics.ActivitySource names to be added to the tracer at the startup. Use it to capture manually instrumented spans. |
Experimental | |
OTEL_DOTNET_AUTO_TRACES_ADDITIONAL_LEGACY_SOURCES |
Comma-separated list of additional legacy source names to be added to the tracer at the startup. Use it to capture System.Diagnostics.Activity objects created without using the System.Diagnostics.ActivitySource API. |
Experimental | |
OTEL_DOTNET_AUTO_FLUSH_ON_UNHANDLEDEXCEPTION |
Controls whether the telemetry data is flushed when an AppDomain.UnhandledException event is raised. Set to true when you suspect that you are experiencing a problem with missing telemetry data and also experiencing unhandled exceptions. |
false |
Experimental |
OTEL_DOTNET_AUTO_METRICS_ADDITIONAL_SOURCES |
Comma-separated list of additional System.Diagnostics.Metrics.Meter names to be added to the meter at the startup. Use it to capture manually created metrics. |
Experimental | |
OTEL_DOTNET_AUTO_PLUGINS |
Colon-separated list of OTel SDK instrumentation plugin types, specified with the assembly-qualified name. Note: This list must be colon-separated because the type names may include commas. See more info on how to write plugins at plugins.md. | Experimental |
RuleEngine is a feature that validates OpenTelemetry API, SDK, Instrumentation, and Exporter assemblies for unsupported scenarios, ensuring that OpenTelemetry automatic instrumentation is more stable by backing of instead of crashing. It works on .NET 8 and higher.
Enable RuleEngine only during the first run of the application, or when the deployment changes or the Automatic Instrumentation library is upgraded. Once validated, there's no need to revalidate the rules when the application restarts.
| Environment variable | Description | Default value | Status |
|---|---|---|---|
OTEL_DOTNET_AUTO_RULE_ENGINE_ENABLED |
Enables RuleEngine. | true |
Experimental |
The CLR uses the following environment variables to set up the profiler. See .NET Runtime Profiler Loading for more information.
| .NET Framework environment variable | .NET environment variable | Description | Required value | Status |
|---|---|---|---|---|
COR_ENABLE_PROFILING |
CORECLR_ENABLE_PROFILING |
Enables the profiler. | 1 |
Experimental |
COR_PROFILER |
CORECLR_PROFILER |
CLSID of the profiler. | {918728DD-259F-4A6A-AC2B-B85E1B658318} |
Experimental |
COR_PROFILER_PATH |
CORECLR_PROFILER_PATH |
Path to the profiler. | $INSTALL_DIR/linux-x64/OpenTelemetry.AutoInstrumentation.Native.so for Linux glibc, $INSTALL_DIR/linux-musl-x64/OpenTelemetry.AutoInstrumentation.Native.so for Linux musl, $INSTALL_DIR/osx-x64/OpenTelemetry.AutoInstrumentation.Native.dylib for macOS |
Experimental |
COR_PROFILER_PATH_32 |
CORECLR_PROFILER_PATH_32 |
Path to the 32-bit profiler. Bitness-specific paths take precedence over generic paths. | $INSTALL_DIR/win-x86/OpenTelemetry.AutoInstrumentation.Native.dll for Windows |
Experimental |
COR_PROFILER_PATH_64 |
CORECLR_PROFILER_PATH_64 |
Path to the 64-bit profiler. Bitness-specific paths take precedence over generic paths. | $INSTALL_DIR/win-x64/OpenTelemetry.AutoInstrumentation.Native.dll for Windows |
Experimental |
Setting OpenTelemetry .NET Automatic Instrumentation as a .NET CLR Profiler is required for .NET Framework.
On .NET, the .NET CLR Profiler is used only for bytecode instrumentation. If having just source instrumentation is acceptable, you can unset or remove the following environment variables:
COR_ENABLE_PROFILING
COR_PROFILER
COR_PROFILER_PATH_32
COR_PROFILER_PATH_64
CORECLR_ENABLE_PROFILING
CORECLR_PROFILER
CORECLR_PROFILER_PATH
CORECLR_PROFILER_PATH_32
CORECLR_PROFILER_PATH_64On .NET it is required to set the
DOTNET_STARTUP_HOOKS
environment variable.
The DOTNET_ADDITIONAL_DEPS
and DOTNET_SHARED_STORE
environment variable are used to mitigate assembly version conflicts in .NET.
| Environment variable | Required value | Status |
|---|---|---|
DOTNET_STARTUP_HOOKS |
$INSTALL_DIR/net/OpenTelemetry.AutoInstrumentation.StartupHook.dll |
Experimental |
DOTNET_ADDITIONAL_DEPS |
$INSTALL_DIR/AdditionalDeps |
Experimental |
DOTNET_SHARED_STORE |
$INSTALL_DIR/store |
Experimental |
The default directory paths for internal logs are:
- Windows:
%ProgramData%\OpenTelemetry .NET AutoInstrumentation\logs - Linux:
/var/log/opentelemetry/dotnet - macOS:
/var/log/opentelemetry/dotnet
If the default log directories can't be created, the instrumentation uses the path of the current user's temporary folder instead.
| Environment variable | Description | Default value | Status |
|---|---|---|---|
OTEL_DOTNET_AUTO_LOG_DIRECTORY |
Directory of the .NET Tracer logs. | See the previous note on default paths | Experimental |
OTEL_LOG_LEVEL |
SDK log level. (supported values: none,error,warn,info,debug) |
info |
Stable |
OTEL_DOTNET_AUTO_LOGS_INCLUDE_FORMATTED_MESSAGE |
Whether the log state should be formatted. | false |
Experimental |