Serverless and App Services

Question 1

By default, what can AWS lambda functions access?

Answer 1

Public AWS services and the public internet.

Question 2

What are lambda execution roles?

Answer 2

Enable lambda function to interact with AWS services and resources.

Question 3

How can lambda interact with instances in a private VPC?

Answer 3

Configure the lambda function to run within the VPC.

Question 4

What controls the services and accounts that can invoke lambda functions?

Answer 4

Lambda resource policy

Question 5

What AWS service can you use to get information about function success/failures, retries, latency?

Answer 5

Cloudwatch - specifically metrics

Question 6

What is the difference between synchronous and asynchronous function invocation?

Answer 6

Synchronous: Pass data, get response of success or failure, typically done by human via CLI or API Gateway
Asynchronous: Typically done by AWS service, lambda handles retry upon failure (max 2 retries)

Question 7

When is event source mapping used to invoke a lambda function?

Answer 7

Used on streams and queues which don’t support event generation to invoke lambda

Question 8

What indicates the latest version of a lambda function?

Answer 8

$Latest

Question 9

What is an execution context?

Answer 9

The environment a lambda function runs in. Can be cold (start form scratch) or warm (ready to go).

Question 10

What is the main advantage of EventBridge over CloudWatch?

Answer 10

You can configure multiple event busses to route events to targets.

Question 11

What is the main functionality of SNS?

Answer 11

Coordinates sending and delivery of messages

Question 12

What types of messages are sent with SNS?

Answer 12

Texts, Email, mobile push, HTTP

Question 13

What is the max size of an SNS message?

Answer 13

256 KB

Question 14

What can you use when you want a stateful lambda execution or want to chain multiple lambda functions together?

Answer 14

Step functions

Question 15

True or False: API Gateway cannot be used to connect to on premise endpoints

Answer 15

False

Question 16

In API Gateway, a _________ endpoint is used to route incoming requests to nearest CloudFront POP.

Answer 16

Edge-Optimized

Question 17

How does API Gateway avoid calling backend services on every single request?

Answer 17

Caching

Question 18

How do ASGs interact with SQS?

Answer 18

ASGs can scale based on length of a queue

Question 19

What are the two types of SQS queues?

Answer 19

Standard and FIFO

Question 20

How can you reduce cost of polling SQS queue?

Answer 20

Make fewer requests (polling the queue)

Question 21

What types of encryption is available within SQS?

Answer 21

At rest and in transit

Question 22

Using batching, what is the max amount of messages per second you can obtain per second from a FIFO queue?

Answer 22

3,000

Question 23

Kinesis streams store a ________ window of data.

Answer 23

24 hour

Question 24

For an additional cost, kinesis streams can store __ days worth of data.

Answer 24

7

Question 25

What should I add to increase how much data can live on a data stream?

Answer 25

shards

Question 26

Why might you want to use Kinesis Data Firehose?

Answer 26

To load data for data lakes, data stores, or other analytics services.

Question 27

_____ allows real time data processing using SQL

Answer 27

Kinesis Data Analytics

Question 28

What is the difference between Cognito User Pools and Cognito Identity Pools?

Answer 28

User pools are for user directory management and profiles, sign up, sign in, MFA. Identity pools are for granting temporary AWS credentials.

Question 29

In Cognito, what allows swapping google, facebook, twitter, saml, etc. credentials for short term AWS credentials?

Answer 29

Federated Identities/Identity Federation