Lambda

Question 1

Lambda lets you run code without having to provision or manage servers. And this is called _____

Answer 1

Serverless

Question 2

You’re only charged for requests and the compute time requests consume. There is no charge when your app is not used.
True or False

Answer 2

True

Question 3

AWS Lambda stores code in _____ and encrypts it at rest.

Answer 3

Amazon S3

Question 4

What are the benefits of Lambda ?

Answer 4

1. No servers to manage ( zero administration)
2. Continuous scaling
3. Cost optimized
4. Consistent performance at any scale

Question 5

You are charged for every millisecond your code executes and the number of times your code is triggered. You won’t pay if it is not used.
True or False

Answer 5

True

Question 6

With AWS Lambda, you can optimize your code execution time by choosing the right _____ size for your function.

Answer 6

memory

Question 7

In Lambda, you can also keep your functions initialized and hyper-ready to respond within double digit milliseconds by enabling ____

Answer 7

Provisioned Concurrency

Question 8

Serverless functions ?

Answer 8

1. Event driven (file uploads, scheduled times, API requests)
2. Code focused
3. Managed machines
4. Cost effective
5. Service integration
6. Scaling

Question 9

A Lambda function’s _____ is an IAM role that grants the function permission to access AWS services and resources. You provide this role when you create a function, and Lambda assumes the role when your function is invoked. For example, Amazon CloudWatch for logs, and DynamoDB for storing data.

Answer 9

execution role

Question 10

A ____ permission policy to allow an AWS service to invoke your function on your behalf.

Answer 10

resource-based

Question 11

When AWS Lambda integrates with other AWS services to invoke functions, you can configure ___

Answer 11

1. triggers to invoke a function for other resources’ lifecycle events
2. respond to incoming HTTP requests
3. consume events from other resources such a queue
4. run on a schedule.

Question 12

Each service that integrates with Lambda sends data to your function in _____ as an event.

Answer 12

JSON

Question 13

When other services invoke your function directly
• You grant the other service permission in the function’s _____ policy
• Configure the other service to generate events and ___ your function.

Answer 13

resource-based,

invoke

Question 14

Depending on the service, the Lambda invocation can be _____ or ______.

Answer 14

synchronous,

asynchronous

Question 15

Services that do synchronous invocation on lambda are:

Answer 15

1. Elastic Load Balancing (Application Load Balancer)
2. Amazon Cognito
3. Amazon API Gateway
4. Amazon CloudFront (Lambda@Edge)
   And more…

Question 16

For asynchronous invocation, Lambda queues the event before passing it to your function.
The other service gets a success response as soon as the event is queued and isn’t aware of what happens afterwards.
True or False

Answer 16

True

Question 17

Services that do asynchronous invocation on lambda are:

Answer 17

1. S3
2. SNS (Simple Notification Service)
3. SQS

Question 18

You can use _____ to adjust your function’s behavior without updating code.

Answer 18

environment variables

Question 19

What is an environment variable ?

Answer 19

It is a pair of strings that are stored in a function’s version specific configuration.

Question 20

You don’t need to release the app again for changing a value if there is a change. Instead, just change to environment variable at run time. The Lambda runtime makes environment variables available to your code.
True or False

Answer 20

True

Question 21

______ is the number of requests that your function is serving at any given time. When the function code finishes running, it can handle another request.

Answer 21

Concurrency

Question 22

If the function is invoked again while a request is still being processed, another instance is allocated, which increases the function’s _____

Answer 22

concurrency

Question 23

Concurrency is subject to a ____ quota that is shared by all functions in a Region. Default quota for concurrent executions is ____.
Can be increased up to hundreds of thousands.

Answer 23

Regional,

1000

Question 24

What are the two types of concurrency controls ?

Answer 24

1. Reserved concurrency

2. Provisioned concurrency

Question 25

Provisioned concurrency solves cold-start problem. Configuring provisioned concurrency incurs charges to your AWS account.
True or False

Answer 25

True

Question 26

You can use versions to manage the deployment of your functions. There is a unique Amazon Resource Name (ARN) to identify the specific version of the function.
True or False

Answer 26

True

Question 27

What is lambda alias ?

Answer 27

A Lambda alias is like a pointer to a specific function version.

Question 28

There are 2 benefits of using aliases instead of version in production:

Answer 28

1. You can switch versions back and forth.
2. You can implement canary deployment with it.
   A canary deployment is a deployment strategy that releases an app’s new version incrementally to a subset of users.

Question 29

AWS Lambda includes a ____ temporary file system (EFS) for your code, this is not intended for durable storage.

Answer 29

512-MB

Question 30

With lambda using EFS you can easily share data across function invocations, and also read large reference data files, and write function output to a persistent and shared store.
True or False

Answer 30

True

Question 31

The number of maximum concurrent connections for a relational database depends on how it is sized. Lambda functions can scale to tens of thousands of concurrent connections, meaning your database
needs more resources to maintain connections instead of executing queries.
True or False

Answer 31

True

Question 32

When should you use Lambda over EC2

Answer 32

Use lambda when

1. you don’t have many developers to manage servers
2. you want faster development
3. number of transactions are unpredictable
4. the max number of transactions are hundreds or thousands at a second

Question 33

When should you use EC2 over Lambda

Answer 33

Use EC2 when

1. you need to manage the underlying
2. number of transactions are predictable, relatively consistent over time.
3. large number of transactions at a time