Development with AWS Services

Question 1

CloudWatch Evaluation Period

Answer 1

number of the most recent periods, or data points, to evaluate when determining alarm state

Question 2

CloudWatch Period

Answer 2

• length of time to evaluate the metric or expression to create each individual data point for an alarm
• expressed in seconds
• if you choose one minute as the period, there is one datapoint every minute

Question 3

CloudWatch Datapoints to Alarm

Answer 3

• number of data points within the evaluation period that must be breaching to cause the alarm to go to the ALARM state
• breaching data points do not have to be consecutive, they just must all be within the last number of data points equal to Evaluation Period

Question 4

How would you redirect users to a specific version of a site eg. https://tutorialsdojo.com/uk/ for uk users?

Answer 4

Implement a CloudFront function that returns the appropriate URL based on the CloudFront-Viewer-Country. Configure the distribution to trigger the function on Viewer request events.

Question 5

What does CodeDeployDefault.LambdaCanary10Percent5Minutes do?

Answer 5

10 percent of your customer traffic is immediately shifted to your new version. After 10 minutes, all traffic is shifted to the new version

Question 6

What does
CodeDeployDefault.LambdaLinear10PercentEvery1Minute do?

Answer 6

it will add 10 percent of the traffic linearly to the new version every minute

Question 7

What does CodeUri property do in CloudFormation?

Answer 7

used primarily with AWS SAM (Serverless Application Model) to specify the location of your Lambda function code

Question 8

What does ‘aws cloudformation package’ command do?

Answer 8

zips local code, uploads it to s3, updates the template to reference the code in s3

Question 9

What is the concurrency limit of AWS Lambda?

Answer 9

By default, AWS Lambda limits the total concurrent executions across all functions within a given region to 1000. This limit can be raised by requesting for AWS to increase the limit of the concurrent executions of your account.

Question 10

What is global secondary index?

Answer 10

• Creates completely new index with different partition key
• Queries across ALL partitions
• Flexible querying on any attributes
  eg. Query orders by OrderDate for all customers

Question 11

What is a local secondary index?

Answer 11

• Uses SAME partition key as main table
• Only sorts data WITHIN a partition differently
• Queries limited to single partition
  eg. Query orders by OrderStatus for a specific customer

Question 12

What is an Elastic Beanstalk worker environment?

Answer 12

an environment in AWS Elastic Beanstalk that allows you to run applications meant to process background activities, such as processing data, executing scheduled tasks, or sending emails. Your application receives tasks from an Amazon SQS (Simple Queue Service) queue and processes them

Question 13

Why cant transfer acceleration be used on a bucket called data.tutorialsdojo.com?

Answer 13

the name of the bucket used for Transfer Acceleration must be DNS-compliant and must not contain periods (“.”)

Question 14

How to invalidate existing cache entry to get latest result from DB?

Answer 14

• client must send a request that contains the Cache-Control: max-age=0 header
• ticking the Require authorization checkbox ensures that not every client can invalidate the API cache (significant increase in latency)

Question 15

What ratio of instances to shards should you have when using Kinesis Client Library?

Answer 15

1:1 ratio (eg. 6 shards 6 instances)

Number of instances should not exceed number of shards, but shards can exceed number of instances

Question 16

What is Amazon Kinesis Data Streams?

Answer 16

allows you to collect, process, and analyze real-time, streaming data eg. real time monitoring, log and event data collection

Question 17

What is Amazon Data Firehose?

Answer 17

• load streaming data into data lakes, data warehouses, and analytics services
• deliver to s3, redshift, elasticsearch service, splunk

Question 18

What is Amazon Kinesis Agent?

Answer 18

lightweight software that helps send log and event data from on-premises servers to Amazon Kinesis Data Streams or Data Firehose, not a service for streaming itself

Question 19

What is provisioned capacity for DynamoDB?

Answer 19

• You specify the number of read and write capacity units (RCUs and WCUs) you expect your application to need
• DynamoDB allocates the necessary resources based on these specified units
• Pay for provisioned RCUs and WCUs regardless if you use them

Question 20

What is on-demand capacity for DynamoDB?

Answer 20

• automatically scales based on the actual traffic received by the table
• you do not need to specify RCUs and WCUs
• more expensive than provisioned capacity

Question 21

What is HTTP_PROXY integration?

Answer 21

• API Gateway acts as a straightforward proxy, forwarding the entire request to the backend HTTP endpoint and then returning the response directly to the client
• API Gateway simply passes through the requests and responses, without any added processing or transformation

Question 22

What is AWS integration?

Answer 22

allows API Gateway to call AWS service actions (e.g., invoking a Lambda function, reading from DynamoDB) directly

Question 23

What is AWS_PROXY integration?

Answer 23

special case of AWS integration specifically designed for invoking Lambda functions via a proxy

Question 24

What is HTTP integration?

Answer 24

allows API Gateway to call any HTTP endpoint, whether it’s inside or outside AWS. You can manage and transform the request and response using API Gateway settings

Question 25

What are stages for HTTP APIs in API Gateway?

Answer 25

- An API stage is a logical reference to a lifecycle state of your API (for example, dev, prod, beta, or v2) - API stages are identified by their API ID and stage name, and they're included in the URL you use to invoke the API