Exception reporting specification

specification/trace/api.md

@@ -25,6 +25,7 @@ Table of Contents
     * [Set Status](#set-status)
     * [UpdateName](#updatename)
     * [End](#end)
+    * [Record Exception](#record-exception)
   * [Span lifetime](#span-lifetime)
 * [Status](#status)
   * [StatusCanonicalCode](#statuscanonicalcode)
@@ -515,6 +516,19 @@ Parameters:
 
 This API MUST be non-blocking.
 
+#### Record Exception
+
+To facilitate recording an exception languages SHOULD provide a
+`RecordException` convenience method. The signature of the method is to be
+determined by each language and can be overloaded as appropriate. The method
+MUST record an exception as an `Event` with the conventions outlined in the
+[exception semantic conventions](semantic_conventions/exceptions.md) document.
+
+Examples:
+
+- `RecordException(exception: Exception)`
+- `RecordException(type: String, message: String, stacktrace: String)`
+
 ### Span lifetime
 
 Span lifetime represents the process of recording the start and the end

specification/trace/semantic_conventions/exceptions.md

@@ -0,0 +1,58 @@
+# Semantic Conventions for Exceptions
+
+This document defines semantic conventions for recording application
+exceptions.
+
+<!-- toc -->
+
+- [Recording an Exception](#recording-an-exception)
+- [Attributes](#attributes)
+  - [Stacktrace Representation](#stacktrace-representation)
+
+<!-- tocstop -->
+
+## Recording an Exception
+
+An exception SHOULD be recorded as an `Event` on the span during which it occurred.
+The name of the event MUST be `"exception"`.
+
+## Attributes
+
+The table below indicates which attributes should be added to the `Event` and
+their types.
+
+| Attribute name       | Type   | Notes and examples                                                                                                                                                                                                                                                                                                                                                                                                                  | Required?                                                  |
+| :------------------- | :----- | :---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | :--------------------------------------------------------- |
+| exception.type       | String | The type of the exception (its fully-qualified class name, if applicable). The dynamic type of the exception should be preferred over the static type in languages that support it. E.g. "java.net.ConnectException", "OSError"                                                                                                                                                                                                     | One of `exception.type` or `exception.message` is required |
+| exception.message    | String | The exception message. E.g. `"Division by zero"`, `"Can't convert 'int' object to str implicitly"`                                                                                                                                                                                                                                                                                                                                  | One of `exception.type` or `exception.message` is required |
+| exception.stacktrace | String | A stacktrace as a string in the natural representation for the language runtime. The representation is to be determined and documented by each language SIG. E.g. `"Exception in thread \"main\" java.lang.RuntimeException: Test exception\n at com.example.GenerateTrace.methodB(GenerateTrace.java:13)\n at com.example.GenerateTrace.methodA(GenerateTrace.java:9)\n at com.example.GenerateTrace.main(GenerateTrace.java:5)"`. | No                                                         |
+
+### Stacktrace Representation
+
+The table below, adapted from [Google Cloud][gcp-error-reporting], includes
+possible representations of stacktraces in various languages. The table is not
+meant to be a recommendation for any particular language, although SIGs are free
+to adopt them if they see fit.
+
+| Language   | Format                                                              |
+| ---------- | ------------------------------------------------------------------- |
+| C#         | the return value of [Exception.ToString()][csharp-stacktrace]       |
+| Go         | the return value of [runtime.Stack][go-stacktrace]                  |
+| Java       | the contents of [Throwable.printStackTrace()][java-stacktrace]      |
+| Javascript | the return value of [error.stack][js-stacktrace] as returned by V8  |
+| Python     | the return value of [traceback.format_exc()][python-stacktrace]     |
+| Ruby       | the result of [Exception.backtrace][ruby-stacktrace] joined by "\n" |
+
+Backends can use the language specified methodology for generating a stacktrace
+combined with platform information from the
+[telemetry sdk resource][telemetry-sdk-resource] in order to extract more fine
+grained information from a stacktrace, if necessary.
+
+[gcp-error-reporting]: https://cloud.google.com/error-reporting/reference/rest/v1beta1/projects.events/report
+[java-stacktrace]: https://docs.oracle.com/javase/7/docs/api/java/lang/Throwable.html#printStackTrace%28%29
+[python-stacktrace]: https://docs.python.org/3/library/traceback.html#traceback.format_exc
+[js-stacktrace]: https://v8.dev/docs/stack-trace-api
+[ruby-stacktrace]: https://ruby-doc.org/core-2.7.1/Exception.html#method-i-backtrace
+[csharp-stacktrace]: https://docs.microsoft.com/en-us/dotnet/api/system.exception.tostring
+[go-stacktrace]: https://golang.org/pkg/runtime/debug/#Stack
+[telemetry-sdk-resource]: https://github.com/open-telemetry/opentelemetry-specification/tree/master/specification/resource/semantic_conventions#telemetry-sdk