X-Practice Exams

Question 1

In the context of S3, what can Error 409 be a result of?

Answer 1

Bucket already exists or attempting to remove a bucket without first deleting the items

Question 2

How is long-polling actually used?

Answer 2

By setting the RecieveMessageWaitTimeSeconds parameter of the API call

Question 3

What error is displayed if a CloudFormation stack fails during deployment?

Answer 3

ROLLBACK_IN_PROGRESS

Question 4

Can bucket names include uppercase characters?

Answer 4

No

Question 5

How can X-Ray results be filtered to those that fail and are for a particular domain?

Answer 5

“ok=false AND http.url CONTAINS …”

Note that ‘http.result’ is not valid

Question 6

Does CodeDeploy support in-place Lambda deplyments?

Answer 6

No

Question 7

What push notifications services does SNS plug into?

Answer 7

GCM - Google Cloud Messager

APNS - Apple Push Notification Service

Question 8

How are CodeDeploy build environments configured?

Answer 8

Either use a pre-defined environment or give it a container image. It does not support AMIs

Question 9

What is the best option for managing state in applications behind a load balancer?

Answer 9

ElasticCache

Question 10

How can conflicts be avoided where multiple users write to the same DynamoDB item at the same time?

Answer 10

With conditional writes

Question 11

What encryption algorithm does S3 use?

Answer 11

AES256

Question 12

How can the URLs used to access S3 content be restricted?

Answer 12

With an AWS: referer condition in the bucket policy

Question 13

Where is API Gateway caching set?

Answer 13

At the staging level

Question 14

How do workers signify that they are completed an SQS task?

Answer 14

With the DeleteMessage API call - otherwise it goes back into the queue after the visibility timeout

Question 15

What Step Function state is used to delay execution?

Answer 15

A wait state

Question 16

What tasks can humans perform in SWF?

Answer 16

They can perform work tasks but not decision tasks

Question 17

What do SNS messages consist of?

Answer 17

Message, signature, subjects and type

Question 18

What is the default DynamoDB table limit?

Answer 18

256 per region

Question 19

Do MultiAZ RDS deployments improve performance?

Answer 19

No - it’s a hot standby that doesn’t support reads or writes

Question 20

How do read replicas import the availability of RDS?

Answer 20

They can still be read from if the main instance goes down

Depending on the DB engine, they can be promoted to a master instance

Question 21

Can RDS deployments span regions?

Answer 21

MultiAZ instances can but read replicas can be in a different region

Question 22

Is throughput provisioned per table or per index?

Answer 22

It is for the table/LSI and any GSIs

Question 23

What secret storage solutions support automatic rotation?

Answer 23

System Parameter Store doesn’t support rotation but Secrets Manager does

Question 24

What logs does RDS provide?

Answer 24

Slow query, error and general

Question 25

How can you implement blue/green deployments for an existing Elastic Beanstalk application?

Answer 25

Create a new environment and then do a DNS swap when you are ready

Question 26

What does X-Ray use to monitor HTTP requests?

Answer 26

Interceptors

Question 27

What command do you use to add data to Redshift?

Answer 27

COPY

Question 28

How do you restrict access to API Gateway endpoints?

Answer 28

Besides IAM and Lambda authorisers, you can use Resource Policies. For example, these can restrict to particular IPs

Question 29

How do you integrate SOAP with API Gateway?

Answer 29

Use a mapping template

Question 30

How do you encrypt data directly with KMS?

Answer 30

If it's less than 4KB, you can use GenerateDataKey Otherwise, you need to use GenerateDataKeyWithoutPlaintext and do the encryption locally

Question 31

How can you off-load long-running tasks in Elastic Beanstalk?

Answer 31

With Worker Environments - use cron.yml at the top level of the code

Question 32

How is the schema of responses defined for APIs?

Answer 32

With Method Response, which is per stage

Question 33

How do you configure custom caching for CloudFront?

Answer 33

- Configure the origin to add an 'Expires' header | - Set a minimum TTL in the CloudWatch cache behaviours

Question 34

What is the key different between Elastic Beanstalk and CodeDeploy?

Answer 34

Elastic Beanstalk provides full control while CodeDeploy only provides hooks

Question 35

Where are configuration files for Elastic Beanstalk stored?

Answer 35

There are stored as .ebextensions/.config

Question 36

How do you do location-based routing in CloudFront?

Answer 36

Use geoproximity - geolocation is a Route53 feature

Question 37

How can you handle SQS messages that have unpredictable processing times?

Answer 37

Use the ChangeMessageVisibility API for per-message changes to request timeout

Question 38

What port is SSH on?

Answer 38

22/TCP

Question 39

What is the largest single PUT that S3 supports?

Answer 39

5 GB but AWS recommend using multi-part uploads for anything bigger than 100 MB

Question 40

What is the difference between blue/green and immutable deployments using Elastic Beanstalk?

Answer 40

Blue/green uses separate environments and a DNS swap Immutable sets up a temporary ELB in the same environment

Question 41

Can SQS be a target of SNS?

Answer 41

No

Question 42

What do ASGs do with instances that fail their health checks?

Answer 42

Terminate them

Question 43

How do you define CodeDeploy deployments?

Answer 43

With a .appspec in the root directory

Question 44

What frameworks does Opsworks support?

Answer 44

Chef and Puppet

Question 45

What does Error 400 indicate?

Answer 45

There is a problem with your request i.e. you are missing parameters or exceeding the provisioned throughput of a table

Question 46

How you ensure frequent custom metrics?

Answer 46

Enable high-resolution metrics; detailed monitoring is for EC2

Question 47

How can you tell how much capacity a query has taken?

Answer 47

By setting the ReturnConsumedCapacity parameter to TOTAL

Question 48

How can you configure CloudFront to force HTTPS?

Answer 48

By using a Viewer Protocol Policy

Question 49

What services support deployment to Lambda?

Answer 49

CodeDeploy and CloudFormation but NOT Elastic Beanstalk