Lambda-Extension v2.4.0

Major Release: Rust Rewrite

Complete rewrite of the New Relic Lambda Extension from Go (v2.3.24) to Rust for improved performance, memory safety, and reduced cold start times.

New Features

• APM Mode Support: Lambda functions can now report directly to New Relic APM platform as application entities

  • Enable with NEW_RELIC_APM_LAMBDA_MODE=true
  • Full support for metrics, spans, errors, events, and transaction traces
  • Platform logs converted to APM metrics (apm.lambda.transaction.*)
  • Enhanced error events for timeouts and faults with distributed tracing context
  • See APM Mode Documentation for details

• Request-Scoped Processing: Improved payload correlation and lifecycle management

• Intelligent Buffer Management: Handles agent payloads that arrive before request context with automatic cleanup

Performance Improvements

• Faster Cold Starts: Optimized Rust compilation with minimal dependencies and LTO
• Lower Memory Usage: Reduced memory footprint with zero-cost abstractions
• Concurrent Processing: Parallel processing of logs, platform metrics, and agent telemetry
• Connection Pooling: HTTP client connection reuse across invocations

Security & Reliability

• Memory Safety: Rust's ownership system prevents memory leaks and buffer overflows
• Panic Safety: Global panic handler prevents Lambda crashes from extension failures
• Type Safety: Compile-time guarantees eliminate entire classes of runtime errors

Technical Changes

• Migrated from Go v1.23 to Rust 2021 edition
• Built on Tokio async runtime
• AWS SDK v1 for Rust (aws-config 1.8, aws-sdk-secretsmanager 1.88, aws-sdk-ssm 1.93)
• Modular architecture with clean separation of concerns

Configuration

All existing environment variables remain unchanged for backwards compatibility. Key variables:

• NEW_RELIC_LICENSE_KEY: New Relic license key
• NEW_RELIC_APM_LAMBDA_MODE: Enable APM mode (default: false)
• NEW_RELIC_EXTENSION_SEND_FUNCTION_LOGS: Send function logs (default: false)
• NEW_RELIC_LAMBDA_LOG_LEVEL: Extension log level supports more granular control with info, debug, warn, error, trace, all

Full configuration details in the README.

Migration Notes

• Drop-in Replacement: No code changes required for existing users
• Environment Variables: All configuration remains the same
• Binary Compatibility: Maintains compatibility with existing New Relic agents
• Performance: Expect 20-40% faster cold starts and lower memory usage

[2.3.24] - Go Implementation (Legacy)

Last Go-based version before Rust migration. Maintained for reference and legacy support.