AWS: API, Dynamo and Lambda

What are serverless functions?

serverless functions are single-purpose, programmatic functions that are hosted on managed infrastructure. These functions, which are invoked through the Internet, are hosted and maintained by cloud computing companies.

If you were to create a system that emulated Lambda functions, how would you do it?

To create a Lambda function with the console

1. Open the Functions page on the Lambda console.

2. Choose Create function.

3. Under Basic information, do the following:

   1. For Function name, enter my-function.

   2. For Runtime, confirm that Node.js 14.x is selected. Note that Lambda provides runtimes for .NET (PowerShell, C#), Go, Java, Node.js, Python, and Ruby.

4. Choose Create function.

Lambda creates a Node.js function and an execution role that grants the function permission to upload logs. The Lambda function assumes the execution role when you invoke your function, and uses the execution role to create credentials for the AWS SDK and to read data from event sources.

Describe how a CDN works

To minimize the distance between the visitors and your website’s server, a CDN stores a cached version of its content in multiple geographical locations (a.k.a., points of presence, or PoPs). Each PoP contains a number of caching servers responsible for content delivery to visitors within its proximity.

In essence, CDN puts your content in many places at once, providing superior coverage to your users. For example, when someone in London accesses your US-hosted website, it is done through a local UK PoP. This is much quicker than having the visitor’s requests, and your responses, travel the full width of the Atlantic and back.

Terms

Term	Def
Serverless Functions	are single-purpose, programmatic functions that are hosted on managed infrastructure. These functions, which are invoked through the Internet, are hosted and maintained by cloud computing companies.
Cloud Storage	Cloud storage is a cloud computing model that stores data on the Internet through a cloud computing provider who manages and operates data storage as a service. It’s delivered on demand with just-in-time capacity and costs, and eliminates buying and managing your own data storage infrastructure. This gives you agility, global scale and durability, with “anytime, anywhere” data access.
CDN	Content delivery networks (CDN) are the transparent backbone of the Internet in charge of content delivery. Whether we know it or not, every one of us interacts with CDNs on a daily basis; when reading articles on news sites, shopping online, watching YouTube videos or perusing social media feeds.