Title

AWS re:Invent 2023 - Getting the most performance for your .NET apps from AWS SDK for .NET (XNT401)

Summary

Norman Johanson, a Principal Engineer at AWS, focuses on .NET tooling for AWS applications.
The session covers performance optimization techniques for the AWS SDK for .NET.
The AWS SDK for .NET is a family of NuGet packages with a consistent programming model across AWS services.
The SDK has been stable over the years, with the current major version being version 3.
Key recommendations include reusing service clients, caching credentials, and understanding the SDK's default behavior.
The SDK caches HTTP clients to reduce TLS negotiation overhead, but this can be customized or disabled.
The Security Token Service (STS) defaults to the US East 1 region, but this can be changed to reduce latency and dependency on multiple regions.
The SDK's retry behavior is configurable, with a new adaptive retry mode that adjusts to throttling errors.
High-level libraries for DynamoDB have been updated to improve startup times by avoiding describe table calls.
S3 streaming support has been improved to handle non-seekable streams by buffering in chunks.
Native AOT support in .NET 8 allows for faster cold start performance in Lambda functions, but requires careful handling of dependencies and trimming.
The AWS SDK for .NET version 3.7.300 addresses trim warnings and adds a .NET 8 target, but some features are not yet supported in Native AOT.
Feedback and contributions to the SDK are encouraged via GitHub.

Reusing service clients and caching credentials are critical for performance and avoiding unnecessary network calls.
The SDK's default behavior, such as caching HTTP clients and defaulting STS to US East 1, is designed for backward compatibility but can be overridden for performance gains.
The adaptive retry mode is a significant feature for handling throttling errors gracefully and maintaining application performance.
The recent updates to high-level libraries, particularly for DynamoDB, can significantly improve startup times, which is crucial for serverless applications like AWS Lambda.
The support for S3 streaming with non-seekable streams is a valuable addition for web applications handling large file uploads.
Native AOT support in .NET 8 offers promising cold start performance improvements for Lambda functions, but it requires careful consideration of the SDK's limitations and proper testing.
The AWS SDK for .NET's move to address trim warnings and add a .NET 8 target shows a commitment to staying current with .NET developments and improving performance for serverless applications.
The session emphasizes the importance of community feedback in guiding the future development of the AWS SDK for .NET, particularly in areas like Native AOT support.