This chapter is about digging into what it means to build Lambda functions—what do they look like,
how do you configure how they run, and how do you specify your own environmental configuration.
You’ll learn about these topics by examining core concepts for Lambda execution environments, input
and output, timeout, memory and CPU, and finally, how Lambda uses environment variables for
application configuration.
To start, let’s take a look at how Lambda functions are executed. Grab your hiking boots—it’s time
to explore.
Core Concepts: Runtime Model, Invocation
In Chapter 2, you created a Java class, uploaded it to the Lambda service somewhere in the
nebulous “cloud,” and magically were able to execute that code.
You didn’t have to consider operating systems, containers, startup scripts, deployment of the code to an actual host, or JVM settings.
Nor did you think about any of those pesky “servers.” So how did your code execute?
To understand this, you need to first understand the basics of the Lambda execution environment, as
shown in Figure 3-1.
Figure 3-1. The Lambda execution environment
The Lambda Execution Environment
As we mentioned in Chapter 2 (see “Installing the AWS CLI”), both AWS management and function
operations (often referred to as the control plane and data plane, respectively) make extensive use of APIs. Lambda is ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month, and much more.
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.
Julian F.
Head of Cybersecurity
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.
Addison B.
Field Engineer
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.
Amir M.
Data Platform Tech Lead
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.
