Correct description of OTEL_EXPORTER_JAEGER_ENDPOINT and OTEL_TRACES_EXPORTER (open-telemetry#2333)

* Change description/default of OTEL_EXPORTER_JAEGER_ENDPOINT to point to correct HTTP port

Signed-off-by: Yuri Shkuro <github@ysh.us>

* url

Signed-off-by: Yuri Shkuro <github@ysh.us>

* fix

Signed-off-by: Yuri Shkuro <github@ysh.us>

* footnotes

Signed-off-by: Yuri Shkuro <github@ysh.us>

* cr

Signed-off-by: Yuri Shkuro <github@ysh.us>

* fix

Signed-off-by: Yuri Shkuro <github@ysh.us>

* fix

Signed-off-by: Yuri Shkuro <github@ysh.us>

* fix

Signed-off-by: Yuri Shkuro <github@ysh.us>

Co-authored-by: Carlos Alberto Cortez <calberto.cortez@gmail.com>

Author: yurishkuro

CHANGELOG.md

@@ -17,6 +17,9 @@ release.
 - Add support for probability sampling in the OpenTelemetry `tracestate` entry and
   add optional specification for consistent probability sampling.
   ([#2047](https://github.com/open-telemetry/opentelemetry-specification/pull/2047))
+- Change description and default value of OTEL_EXPORTER_JAEGER_ENDPOINT env var
+  to point to the correct HTTP port and correct description of OTEL_TRACES_EXPORTER
+  ([#2333](https://github.com/open-telemetry/opentelemetry-specification/pull/2333)).
 
 ### Metrics
 

specification/sdk-environment-variables.md

@@ -126,14 +126,16 @@ See [OpenTelemetry Protocol Exporter Configuration Options](./protocol/exporter.
 
 | Name                            | Description                                                      | Default                                                                                          |
 |---------------------------------|------------------------------------------------------------------|--------------------------------------------------------------------------------------------------|
-| OTEL_EXPORTER_JAEGER_AGENT_HOST | Hostname for the Jaeger agent                                    | "localhost"                                                                                      |
+| OTEL_EXPORTER_JAEGER_AGENT_HOST | Hostname for the Jaeger agent [1]                                | "localhost"                                                                                      |
 | OTEL_EXPORTER_JAEGER_AGENT_PORT | Port for the Jaeger agent `compact` Thrift protocol              | 6831                                                                                             |
-| OTEL_EXPORTER_JAEGER_ENDPOINT   | HTTP endpoint for Jaeger traces                                  | <!-- markdown-link-check-disable --> "http://localhost:14250"<!-- markdown-link-check-enable --> |
+| OTEL_EXPORTER_JAEGER_ENDPOINT   | Full URL of [Thrift over HTTP][jaeger_http] endpoint for Jaeger traces [2] | <!-- markdown-link-check-disable --> `"http://localhost:14268/api/traces"` <!-- markdown-link-check-enable --> |
 | OTEL_EXPORTER_JAEGER_TIMEOUT    | Maximum time the Jaeger exporter will wait for each batch export | 10s                                                                                              |
 | OTEL_EXPORTER_JAEGER_USER       | Username to be used for HTTP basic authentication                |                                                                                                  |
 | OTEL_EXPORTER_JAEGER_PASSWORD   | Password to be used for HTTP basic authentication                |                                                                                                  |
 
-See [Jaeger Agent](https://www.jaegertracing.io/docs/latest/deployment/#agent) documentation.
+[1] See [Jaeger Agent](https://www.jaegertracing.io/docs/latest/deployment/#agent) documentation.
+
+[2] When the exporter uses the gRPC protocol, the environment variable refers to the gRPC endpoint and the default value should be `http://localhost:14250`.
 
 ## Zipkin Exporter
 
@@ -179,7 +181,11 @@ The SDK MAY accept a comma-separated list to enable setting multiple exporters.
 Known values for `OTEL_TRACES_EXPORTER` are:
 
 - `"otlp"`: [OTLP](./protocol/otlp.md)
-- `"jaeger"`: [Jaeger gRPC](https://www.jaegertracing.io/docs/1.21/apis/#protobuf-via-grpc-stable)
+- `"jaeger"`: export in Jaeger data model. If no additional configuration is
+  provided the default protocol SHOULD be [Thrift over HTTP][jaeger_http] unless
+  SDKs have good reasons to choose [gRPC][jaeger_grpc] as the default
+  (e.g. for backward compatibility reasons when gRPC was already the default
+  in a stable SDK release).
 - `"zipkin"`: [Zipkin](https://zipkin.io/zipkin-api/) (Defaults to [protobuf](https://github.com/openzipkin/zipkin-api/blob/master/zipkin.proto) format)
 - `"none"`: No automatically configured exporter for traces.
 
@@ -222,3 +228,6 @@ To ensure consistent naming across projects, this specification recommends that
 ```
 OTEL_{LANGUAGE}_{FEATURE}
 ```
+
+[jaeger_http]: https://www.jaegertracing.io/docs/latest/apis/#thrift-over-http-stable
+[jaeger_grpc]: https://www.jaegertracing.io/docs/latest/apis/#protobuf-via-grpc-stable