Cherry-pick replay-aware logger into feature branch#2405
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GarrettBeatty merged 2 commits intoJun 3, 2026
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Implement context.Logger, the replay-aware ILogger described in
Docs/durable-execution-design.md and shipped by the Python / Java / JS
reference SDKs. Messages emitted while the workflow is replaying prior
operations are suppressed, so a 30-step workflow re-invoked 30 times
emits each LogInformation line once instead of 30 times.
Public API:
- IDurableContext.Logger — was NullLogger.Instance, now a replay-safe
ILogger backed by Amazon.Lambda.Core.LambdaLogger so logs flow into
the standard runtime pipeline (JSON when AWS_LAMBDA_LOG_FORMAT=JSON,
level-filtered by AWS_LAMBDA_LOG_LEVEL).
- IDurableContext.ConfigureLogger(LoggerConfig) — swap the inner
ILogger (Serilog, Powertools, etc.) and/or disable replay-aware
filtering (ModeAware = false) for debugging. Matches the API shape
documented in the design doc.
Internals:
- ReplayAwareLogger — ILogger decorator that consults
ExecutionState.IsReplaying on every Log call. Short-circuits both
Log<TState> and IsEnabled during replay so LoggerExtensions.LogXxx
doesn't even format the string. BeginScope always passes through so
the scope stack stays balanced.
- LambdaCoreLogger — minimal in-package adapter that delegates to
Amazon.Lambda.Core.LambdaLogger.Log. Avoids forcing a dependency on
Amazon.Lambda.Logging.AspNetCore.
- DurableFunction.WrapAsyncCore opens a BeginScope around the workflow
body carrying durableExecutionArn + awsRequestId. StepOperation
opens a per-step scope (operationId, operationName, attempt) around
the user-func invocation only. Structured log providers (the
runtime's JSON formatter, Serilog, etc.) tag every log line emitted
by user code with that metadata automatically.
Tests:
- ReplayAwareLoggerTests — 7 unit tests: replay suppression, execution
passthrough, ModeAware=false, IsEnabled short-circuit, scope
passthrough, mid-workflow REPLAY→NEW transition (mirrors Python's
test_logger_replay_then_new_logging).
- DurableContextTests — coverage for the default logger, ConfigureLogger
with a custom logger, and ConfigureLogger { ModeAware = false }
enabling logs during replay.
- ReplayAwareLoggerTest (integration) — deploys a Step → Wait → Step
workflow that pairs each context.Logger.LogInformation line with a
Console.WriteLine "control" line. After the durable execution
completes, queries CloudWatch Logs and asserts each replay-aware
line appears exactly once across both invocations while each control
line appears once per invocation, proving the suppression works
end-to-end.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Forward template + args from LambdaCoreLogger
When state is FormattedLogValues, extract {OriginalFormat} and pass the
original template + named-argument values through to LambdaLogger.Log
instead of pre-rendering. Mirrors the pattern in
Amazon.Lambda.Logging.AspNetCore.LambdaILogger so the runtime's JSON
formatter can surface {OrderId}-style placeholders as top-level
structured attributes.
Make LambdaCoreLogger scope-aware
BeginScope now maintains an AsyncLocal chain of scope state. On Log,
KVP-shaped scope state is appended to the template as named placeholders
(inner→outer order, inner wins on key collision; explicit message args
win over scope keys). The runtime's JSON formatter promotes the keys
to top-level fields, so durableExecutionArn / operationId / etc. show
up as structured attributes without callers having to swap in a
third-party logger.
Unit tests cover ordering, nested scopes, message-arg precedence,
AsyncLocal isolation, and non-KVP fallback. The integration test now
sets AWS_LAMBDA_LOG_FORMAT=JSON, adds a step-internal log line, and
asserts the scope-derived fields land on the parsed JSON record.
GarrettBeatty
requested review from
normj and
philasmar
and removed request for
a team
![github-advanced-security[bot]](https://avatars.githubusercontent.com/in/57789?s=60&v=4){kind=small}
| # etc.) appear as top-level fields. | ||
| ENV AWS_LAMBDA_LOG_FORMAT=JSON | ||
|
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| ENTRYPOINT ["/var/task/bootstrap"] |
GarrettBeatty
added
the
Release Not Needed
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Summary
feature/durablefunctionGarrettBeatty/stack/4) but never made it into the feature branchTest plan