Scenarios Flashcards
Scenario:
An application running in a local server is converted to
a Lambda function. When the function was tested, an
Unable to import module error showed.
Solution:
Install the missing modules in your application’s folder
and package them into a ZIP file before uploading to
AWS Lambda
Scenario:
A Developer is writing a Lambda function that will be
used to send a request to an API in different
environments (Prod, Dev, Test). The function needs to
automatically invoke the correct API call based on the
environment.
Solution:
Use Environment Variables
Scenario:
A Lambda function needs temporary storage to store
files while executing.
Solution:
Store the files in the /tmp directory
Scenario:
Lambda function is writing data into an RDS database.
The function needs to reuse the database connection
to reduce execution time.
Solution:
Use execution context by placing the database
connection logic outside of the event handler.
Scenario:
A Developer needs to increase the CPU available to a
Lambda function to process data more efficiently.
Solution:
Increase the allocated memory of the function.
Scenario:
A Developer has an application that uses a RESTful API
hosted in API Gateway. The API requests are failing
with a “No ‘Access-Control-Allow-Origin’
header is present on the requested
resource” error message.
Solution:
Enable CORS in the API Gateway Console.
Scenario:
A website integrated with API Gateway requires user
requests to reach the backend server without
intervention from the API Gateway. Which integration
type should be used?
Solution:
HTTP_PROXY
Scenario:
A serverless application is composed of AWS Lambda,
DynamoDB, and API Gateway. Users are complaining
about getting HTTP 504 errors.
Solution:
The API requests are reaching the maximum integration
timeout for API Gateway (29 seconds).
Scenario:
How to invalidate API Gateway cache?
Solution:
- Send a request with a Cache-Control:
max-age header. - Enable the Require Authorization option
on your API cache settings.
Scenario:
A developer needs to deploy different API versions in
API Gateway
Solution:
Use stage variables
Scenario:
A Developer needs a cost-effective solution to delete
session data in a DynamoDB table.
Solution:
Expire session data with DynamoDB TTL
Scenario:
New changes to a DynamoDB table should be recorded
in another DynamoDB table.
Solution:
Use DynamoDB Streams
Scenario:
Reduce the DynamoDB database response time.
Solution:
Use DynamoDB Accelerator (DAX)
Scenario:
Choosing the best partition key for the DynamDB table, involves
Solution:
Using the partition key with the highest cardinality (e.g.
student ID, employee ID)
Scenario:
An application uses a DynamoDB database with Global
Secondary Index. DynamoDB requests are returning a
ProvisionedThroughputExceededException error. Why is
this happening?
Solution:
The write capacity of the GSI is less than the base
table.
Scenario:
What section must be added to a CloudFormation
template to include resources defined by AWS SAM?
Solution:
Transform
Scenario:
A developer needs a reliable framework for building
serverless applications in AWS
Solution:
AWS SAM
Scenario:
A CloudFormation stack creation process failed
unexpectedly.
What happens next?
Solution:
CloudFormation will roll back by deleting resources that
it has already created.
Scenario:
A CloudFormation template will be used across
multiple AWS accounts
Solution:
Use CloudFormation StackSets
Scenario:
It is required that incoming traffic is shifted in two
increments. 10% of the traffic must be shifted in the
first increment, and the remaining 90% should be
deployed after some minutes.
Solution:
Canary
Scenario:
You need to authenticate users of a website using
social media identity profiles.
Solution:
Amazon Cognito Identity Pools
Scenario:
A company has two accounts. The developers from
Account A need to access resources on Account B.
Solution:
Use cross-account access role
Scenario:
Multiple developers need to make incremental code
updates to a single project and then deploy the new
changes.
Describe simplest way to achieve this.
Solution:
Use AWS CodeCommit as the code repository and
directly deploy the new package using AWS
CodeDeploy.
Scenario:
A development team is using CodePipeline to automate
their deployment process. The code changes must be
reviewed by a person before releasing to production
Solution:
Add a manual approval action stage
Scenario:
A Developer needs to decode an encoded authorization
failure message.
Solution:
Use the aws sts
decode-authorization-message command.
Scenario:
How can a Developer verify permission to call a CLI
command without actually making a request?
Solution:
Use the –dry-run parameter along with the CLI
command.
Scenario:
A Developer needs to deploy a CloudFormation
template from a local computer.
Solution:
Use the aws cloudformation package and aws
cloudformation deploy command
Scenario:
A Developer has to ensure that no applications can
fetch a message from an SQS queue that’s being
processed or has already been processed.
Solution:
Increase the VisibilityTimeout value using the
ChangeMessageVisibility API and delete the
message using the DeleteMessage API.
Scenario:
A Developer has created an IAM Role for an application
that uploads files to an S3 bucket. Which API call
should the Developer use to allow the application to
make upload requests?
Solution:
Use the AssumeRole API
https://
How does Lambda scale?
Out (horizontally)
