July 2020 Summaries

AWS Lambda execution leaks occur when executing code runs in a different invocation than the original execution context, creating complexity and potential bugs. This can happen with async handlers using the `require-await` rule or callback-based handlers, which never return a value to the AWS Runtime. To avoid these leaks, use ESLint's `require-await` rule and avoid callbacks in favor of async Promise constructs, such as using `util.promisify` to convert callback-based functions to promise-based async functions. By following these best practices, you can prevent event leaks and ensure deterministic executions in your Nodejs AWS Lambda handler.

In a serverless architecture, monitoring latency issues is crucial to ensure business differentiators are not compromised. To gain observability into our application, we need to leave clues as to what it was doing at any given moment in time, such as logs, metrics, and traces. We need to know what IO operations were performed, when they started and finished, and how these operations affected the overall latency of our application. As serverless adoption ramps up within an organization, more sophisticated tools are required to manage and debug complex applications. While AWS X-Ray is a great service for debugging performance problems quickly, it still requires manual instrumentation effort and has limited support for debugging other types of problems. Services like Lumigo provide a polished and complete solution with no manual instrumentation required, recording far more information about what's happening inside our application, including request and response of every HTTP request, invocation event, and return value of the invocation, allowing for quick debugging without adding debug log messages.