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Making Sense of Big Data
AWS Lambda - 7 things I wished someone told me
A short guide to fast track your journey on AWS Lambda and save money and time
AWS Lambda is quite simple to use but as the same time it can be tricky to implement and optimize. In this post I summarized 3 years of experience working with this service. The result is a list of 7 things I wish I already knew when I started, from service logic, DB connections management and cost optimization. Hope this helps people starting off.
AWS Lambda is Amazon “Function as a Service” (FaaS), a category of cloud computing services that allows customers to run application functionalities without the complexity of maintaining the infrastructure. You pay only for the compute time you consume, which is great, and there is no charge when your code is not running.
1- How it works — Containers creation and recycling
First things first, how does AWS Lambda work?
Each lambda function is executed in a container that provides an isolated execution environment. When a function is executed for the first time, a new container with the appropriate resources will be created to execute it, and the code for the function will be loaded into the container. This happens every time the function’s code is updated or when a previously created container is destroyed.
Although AWS will reuse a container when one is available, after some time this container is destroyed. There is no documentation that describe when a container is destroyed nor what event can trigger its destruction. We must keep in mind that Lambda function should be stateless and we should accept that a container could live few minutes or few seconds.
TAKEAWAY: Lambda need to create an isolated container to execute your code. This container can be destroyed at anytime. Make sure your function’s code is stateless.
