Title

AWS re:Invent 2023 - “Rustifying” serverless: Boost AWS Lambda performance with Rust (COM306)

Summary

• Efi, a senior cloud architect and AWS serverless hero, shares GammaRay's journey of enhancing their serverless Python application by integrating Rust for better performance and cost-efficiency.
• Three strategies were employed:
  1. Rust Bindings: Adding Rust to an existing Python Lambda to replace slow code segments, using PyO3 and Maturin tools.
  2. Rewriting a Lambda from Scratch: Completely rewriting a simple but critical Lambda in Rust, using AWS SAM and Cargo Lambda.
  3. Lambda Extensions: Sharing common behaviors across multiple Lambdas using a Rust-written Lambda extension.
• Rust was chosen for its performance and concurrency support.
• The session included a detailed explanation of how to implement these strategies, the tools required, and the performance gains achieved.
• Efi provided insights into the AWS Rust SDK, the importance of cold start performance, and the benefits of using Rust for Lambda extensions.
• The source code for the session is available on GitHub, along with a dev container configuration for developing Rust for serverless.

Insights

• Rust's Efficiency: Rust's performance and cost benefits are significant, especially with lower memory configurations, making it a compelling choice for optimizing AWS Lambda functions.
• Cold Start Performance: Rust significantly improves cold start times, which is critical for user-facing Lambdas where response time is a key factor.
• Rust SDK in Developer Preview: Despite being in developer preview, the AWS Rust SDK is stable and efficient, though interface changes are expected.
• Learning Curve: While Rust has a steep learning curve, the investment in learning can yield substantial performance and cost benefits for serverless applications.
• Tooling: Tools like PyO3, Maturin, Cargo Lambda, and AWS SAM are essential for integrating Rust into AWS Lambda and streamlining the development process.
• Extensions and Concurrency: Lambda extensions in Rust can offload tasks from the main handler, improving response times without affecting the user experience.
• Rust Bindings: A practical first step in "rustifying" an application is to use Rust bindings to replace slow Python code, particularly Boto3 calls.
• Community and Support: The AWS community, including AWS Heroes like Efi, plays a vital role in sharing knowledge and best practices for serverless development with Rust.