fix(botocore): ensure streamed bedrock spans finish [backport #11499 to 2.16]

[Yun-Kim]

Backport #11499 to 2.16.

Fixes #11295.

There was an issue with the langchain-aws library and our bedrock integration in that langchain-aws' ChatBedrock class was actually resulting in a GeneratorExit because of this code implicitly calling close(stream) under the hood in Python. this means that any post-processor code was actually never reached. Since GeneratorExits do not inherit from Exception (they actually inherit from BaseException), this was not caught in our except Except block, meaning spans never went through either of our post-processing (success or error) code.

The solution is to move post processing code into a finally block, to ensure that spans will always be finished. Note that GeneratorExits are not indicative of actual user/system errors and will not be flagged as such (spans will not be marked with error, post processing will simply include only information available until the last yielded chunk)

Checklist

• [x] PR author has checked that all the criteria below are met
• The PR description includes an overview of the change
• The PR description articulates the motivation for the change
• The change includes tests OR the PR description describes a testing strategy
• The PR description notes risks associated with the change, if any
• Newly-added code is easy to change
• The change follows the library release note guidelines
• The change includes or references documentation updates if necessary
• Backport labels are set (if applicable)

Reviewer Checklist

• [x] Reviewer has checked that all the criteria below are met
• Title is accurate
• All changes are related to the pull request's stated goal
• Avoids breaking API changes
• Testing strategy adequately addresses listed risks
• Newly-added code is easy to change
• Release note makes sense to a user of the library
• If necessary, author has acknowledged and discussed the performance implications of this PR as reported in the benchmarks PR comment
• Backport labels are set in a manner that is consistent with the release branch maintenance policy

[github-actions[bot]]

CODEOWNERS have been resolved as:

releasenotes/notes/fix-bedrock-early-stream-exit-81da39d97fb1b26e.yaml  @DataDog/apm-python
ddtrace/contrib/internal/botocore/services/bedrock.py                   @DataDog/ml-observability
tests/contrib/botocore/test_bedrock.py                                  @DataDog/ml-observability

[datadog-dd-trace-py-rkomorn[bot]]

Datadog Report

Branch report: yunkim/backport-11499-216 Commit report: 7a007eb Test service: dd-trace-py

:white_check_mark: 0 Failed, 592 Passed, 694 Skipped, 19m 37.52s Total duration (15m 14.39s time saved)

[pr-commenter[bot]]

Benchmarks

Benchmark execution time: 2024-11-22 19:21:14

Comparing candidate commit 7a007eb32f1cd351d903820943e29723e4d9997a in PR branch yunkim/backport-11499-216 with baseline commit 09a4236a17787d29f25383aab96fb7708419818e in branch 2.16.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 372 metrics, 2 unstable metrics.