March 2019 Summaries

AWS Lambda has a soft limit of 75GB for deployment packages, which can be quickly reached by teams that frequently deploy and split their package sizes due to cold start performance requirements. This limit creates waste as older versions of functions are rarely used, but a simple solution is available in the Serverless Application Repository (SAR), allowing users to deploy a "lambda-janitor" function that automatically deletes old versions of their functions, freeing up space and reducing waste. The `lambda-janitor` function can be deployed with custom IAM permissions to list and delete function versions, making it easier for developers to manage their Lambda environment and reduce storage costs.

The paper focuses on the impact of web frameworks on serverless applications, specifically cold start issues in AWS Lambda environments. The authors conducted an experiment using five popular NodeJS frameworks and compared their performance with a plain NodeJS package. They found that adding a web framework can introduce latency to the cold start process, but the effect is more significant due to initialization time rather than package size. The results suggest that code initialization time should be the main criterion for choosing a web framework when it comes to minimizing cold start performance. The authors recommend using tools to assess cold start time and not ruling out web frameworks based solely on their size.