Section 19: Serverless

Question 1

What is DynamoDB?

Answer 1

DynamoDB is a fully managed, serverless, highly available, distributed NoSQL DB that scales to massive workloads and can be replicated across multiple AZs

Question 2

Are DynamoDB items good for storing large objects?

Answer 2

No, DynamoDB items are not good for storing large objects as their maximum size is only 400kb

Question 3

What is the maximum Lambda execution time?

Answer 3

15 minutes

Question 4

What is Lambda@Edge?

Answer 4

Lambda@Edge is when you deploy Lambda alongside a CloudFront distribution network (edge locations)

Question 5

What are the three (3) main benefits of Lambda@Edge?

Answer 5

1) More responsive apps
2) Global reach
3) User prioritization

Question 6

What are the two read/write DynamoDB capacity modes?

Answer 6

1) Provisioned mode (default)
2) On-demand mode

Question 7

Explain DynamoDB on-demand read/write mode

Answer 7

Automatically scales with workloads, requiring no capacity planning. It is great for unpredictable workloads but is 2/3x more expensive than provisioned.

Question 8

Explain DynamoDB provisioned read/write mode

Answer 8

You specify the number of read/writes per second and plan capacity before hand. Cheaper.

Question 9

What is DynamoDB Accelerator (DAX)?

Answer 9

DAX is a fully managed, highly available seamless in-memory cache for Dynamo DB.

Question 10

What is a common architecture with DAX and DynamoDB?

Answer 10

DAX sits in front of DynamoDB

Question 11

How does DAX enhance DynamoDB?

Answer 11

It caches the most used data from DynamoDB solving read congestion, and offloads heavy reads to DynamoDB when it needs to.

Question 12

What is a DynamoDB global table? What is the prerequisite to enabling global tables?

Answer 12

DynamoDb Global Tables are DynamoDb tables that are made accessible with low latency in multiple regions. Apps can read and write to the table in any region it exists.

Question 13

What is Amazon API Gateway?

Answer 13

AWS API Gateway is a serverless service that enables stateless communication between a client and server.

Question 14

What are the three API Gateway endpoint types?

Answer 14

1) Edge-optimized (default) for global clients
2) Regional (for clients within same region)
3) Private (for VPCs)

Question 15

What are the two most key API Gateway integrations?

Answer 15

Lambda invocations via API Gateway and HTTP endpoints for backend use.