Chapter 7 - APPLICATION INTEGRATION: Amazon SQS, Amazon SNS, Amazon MQ, Amazon SWF, AWS Step Functions, AWS AppSync

Question 1

How is SQS different from SNS? Choose 2.

1. SNS is a distributed publish-subscribe system. Messages are pushed to subscribers as and when they are sent by publishers to SNS.
2. SQS is distributed queuing system. Messages are NOT pushed to receivers. Receivers have to poll or pull messages from SQS.
3. SNS is a distributed publish-subscribe system. Messages are polled by subscribers as and when they are sent by publishers to SNS.
4. SQS is distributed queuing system. Messages are pushed to receivers.

Answer 1

1. SNS is a distributed publish-subscribe system. Messages are pushed to subscribers as and when they are sent by publishers to SNS.
2. SQS is distributed queuing system. Messages are NOT pushed to receivers. Receivers have to poll or pull messages from SQS.
3. SNS is a distributed publish-subscribe system. Messages are polled by subscribers as and when they are sent by publishers to SNS.
4. SQS is distributed queuing system. Messages are pushed to receivers.

Question 2

You have on-premise distributed applications connected through message broker supporting JMS APIs and AMQP/ MQTT Protocols. You are planning to migrate the whole application portfolio to AWS and re-develop using native AWS services. Which AWS service should you use to replace the message broker architecture layer?

1. Amazon Message Broker
2. Amazon SQS
3. Amazon SWF
4. Amazon MQ

Answer 2

1. Amazon Message Broker
2. Amazon SQS
3. Amazon SWF
4. Amazon MQ

Question 3

Which of the following statements are correct about SQS Standard Queues? Choose 2.

1. Makes a best effort to preserve the order of messages, but more than one copy of a message might be delivered out of order.
2. The order in which messages are sent and received is strictly preserved and a message is delivered once and remains available until a consumer processes and deletes it.
3. Duplicates aren’t introduced into the queue.
4. Ensures At-Least-Once Delivery but may result in duplicate messages on rare occasions.

Answer 3

1. Makes a best effort to preserve the order of messages, but more than one copy of a message might be delivered out of order.
2. The order in which messages are sent and received is strictly preserved and a message is delivered once and remains available until a consumer processes and deletes it.
3. Duplicates aren’t introduced into the queue.
4. Ensures At-Least-Once Delivery but may result in duplicate messages on rare occasions.

Question 4

How does Amazon SQS provide message ordering?

1. SQS doesn’t provide message ordering
2. Through FIFO: First In First Out queues
3. Through Standard Queues
4. Through LIFO: Last In First Out queues
5. Through LILO: Last In Last Out queues

Answer 4

1. SQS doesn’t provide message ordering
2. Through FIFO: First In First Out queues
3. Through Standard Queues
4. Through LIFO: Last In First Out queues
5. Through LILO: Last In Last Out queues

Question 5

Which AWS service you will use if you have to build, run, and scale background jobs that have parallel or sequential steps?

1. Amazon Lambda
2. Amazon Simple Workflow Service (SWF)
3. Amazon Simple Queue Service ( SQS)
4. Amazon Simple Notification Service ( SNS)

Answer 5

1. Amazon Lambda
2. Amazon Simple Workflow Service (SWF)
3. Amazon Simple Queue Service ( SQS)
4. Amazon Simple Notification Service ( SNS)

Question 6

What is visibility timeout in SQS?

1. A period of time during which Amazon SQS makes the message available to other consumers to receive and process the message.
2. A period of time during which Amazon SQS prevents other consumers from receiving and processing the message.
3. A period of time for which delivery of new message is postponed.
4. A period of time during which a message is processed by the consumer.

Answer 6

1. A period of time during which Amazon SQS makes the message available to other consumers to receive and process the message.
2. A period of time during which Amazon SQS prevents other consumers from receiving and processing the message.
3. A period of time for which delivery of new message is postponed.
4. A period of time during which a message is processed by the consumer.

Question 7

What is delay queue in SQS?

1. A period of time during which Amazon SQS makes the message available to other consumers to receive and process the message.
2. A period of time during which Amazon SQS prevents other consumers from receiving and processing the message.
3. A period of time for which delivery of new message is postponed.
4. A period of time during which a message is processed by the consumer.

Answer 7

1. A period of time during which Amazon SQS makes the message available to other consumers to receive and process the message.
2. A period of time during which Amazon SQS prevents other consumers from receiving and processing the message.
3. A period of time for which delivery of new message is postponed.
4. A period of time during which a message is processed by the consumer.

Question 8

Which architecture design consideration will make you choose SQS standard queue over FIFO queue?

1. At-Least-Once Delivery, Unlimited Throughput, Best-Effort Ordering
2. High Throughput, Exactly-Once Processing, First-In-First-Out Delivery
3. Best-Effort Ordering, First-In-First-Out Delivery, Exactly-Once Processing
4. At-Least-Once Delivery, Unlimited Throughput, Exactly-Once Processing,

Answer 8

1. At-Least-Once Delivery, Unlimited Throughput, Best-Effort Ordering
2. High Throughput, Exactly-Once Processing, First-In-First-Out Delivery
3. Best-Effort Ordering, First-In-First-Out Delivery, Exactly-Once Processing
4. At-Least-Once Delivery, Unlimited Throughput, Exactly-Once Processing,

Question 9

The minimum and maximum SQS delay queue settings are?

1. 0 secs, 15 mts
2. 15mts, 30 mts
3. 5mts, 15 mts
4. 10 sec, 15mts

Answer 9

1. 0 secs, 15 mts
2. 15mts, 30 mts
3. 5mts, 15 mts
4. 10 sec, 15mts

Question 10

By default for how many days messages are retained in SQS queue?

1. 1 minute
2. 2 days
3. 4 days
4. 14 days

Answer 10

1. 1 minute
2. 2 days
3. 4 days
4. 14 days

Question 11

You are using Amazon SQS in your ecommerce application to send order confirmation email asynchronously. You have created a program which polls the SQS queue frequently for new order message and then sends the email after fetching new order message from the queue. You observe that at times the program is getting empty response to the ReceiveMessage request. What should you do to eliminate empty responses to reduce cost?

1. Create a delay queue.
2. Increase the duration of visibility timeout value to higher number.
3. Make wait time for the ReceiveMessage API action is greater than 0 to effect long polling.
4. Make wait time for the ReceiveMessage API action is greater than 0 to effect short polling.

Answer 11

1. Create a delay queue.
2. Increase the duration of visibility timeout value to higher number.
3. Make wait time for the ReceiveMessage API action is greater than 0 to effect long polling.
4. Make wait time for the ReceiveMessage API action is greater than 0 to effect short polling.

Question 12

In Amazon SQS what is the difference between delay queue and visibility time out?

1. There is no difference, both of them are same as they make messages unavailable to consumers for a specific period of time.
2. Delay queues makes a message hidden when it is first added to queue, whereas for visibility timeouts a message is hidden only after it is consumed from the queue.
3. Delay queues makes a message hidden after it is consumed from the queue, whereas for visibility timeouts a message is hidden when it is first added to queue.
4. There is no difference, both of them are same as they make messages available to consumers for a specific period of time.

Answer 12

1. There is no difference, both of them are same as they make messages unavailable to consumers for a specific period of time.
2. Delay queues makes a message hidden when it is first added to queue, whereas for visibility timeouts a message is hidden only after it is consumed from the queue.
3. Delay queues makes a message hidden after it is consumed from the queue, whereas for visibility timeouts a message is hidden when it is first added to queue.
4. There is no difference, both of them are same as they make messages available to consumers for a specific period of time.

Question 13

Which architecture design consideration will make you choose FIFO queue over SQS standard queue?

1. At-Least-Once Delivery, Unlimited Throughput, Best-Effort Ordering
2. High Throughput, Exactly-Once Processing, First-In-First-Out Delivery
3. Best-Effort Ordering, First-In-First-Out Delivery, Exactly-Once Processing
4. At-Least-Once Delivery, Unlimited Throughput, Exactly-Once Processing,

Answer 13

1. At-Least-Once Delivery, Unlimited Throughput, Best-Effort Ordering
2. High Throughput, Exactly-Once Processing, First-In-First-Out Delivery
3. Best-Effort Ordering, First-In-First-Out Delivery, Exactly-Once Processing
4. At-Least-Once Delivery, Unlimited Throughput, Exactly-Once Processing,

Question 14

Which of the following is correct about message delivery to SQS Standard queue? Choose 2.

1. Messages are delivered at least once.
2. Messages are delivered only once.
3. Messages are delivered in FIFO.
4. Attempts to preserve the order of messages.

Answer 14

1. Messages are delivered at least once.
2. Messages are delivered only once.
3. Messages are delivered in FIFO.
4. Attempts to preserve the order of messages.

Question 15

What is the minimum and maximum retention time for which messages can be retained in SQS queue? Choose 2.

1. 1 minute
2. 2 days
3. 4 days
4. 14 days

Answer 15

1. 1 minute
2. 2 days
3. 4 days
4. 14 days

Question 16

What is default visibility timeout period for a message in SQS?

1. 1 minute
2. 0 seconds
3. 30 seconds
4. 2 minute

Answer 16

1. 1 minute
2. 0 seconds
3. 30 seconds
4. 2 minute

Question 17

What is minimum and maximum visibility timeout period for a message in SQS? Choose 2.

1. 12 hours
2. 14 days
3. 30 seconds
4. 0 seconds

Answer 17

1. 12 hours
2. 14 days
3. 30 seconds
4. 0 seconds

Question 18

What are the different methods using which message can be delivered to a subscriber to a SNS topic? Choose 2.

1. AWS lambda, AWS SQS, HTTP/s
2. Email, SMS
3. AWS lambda, AWS SQS, HTTP/s, S3
4. Email, SMS, DynamoDB

Answer 18

1. AWS lambda, AWS SQS, HTTP/s
2. Email, SMS
3. AWS lambda, AWS SQS, HTTP/s, S3
4. Email, SMS, DynamoDB

Question 19

What is a ‘fan out ‘scenario?

1. A publisher sends same message to multiple SNS topics or SQS queues
2. Amazon SNS message is sent to a topic and then replicated and pushed to multiple Amazon SQS queues, HTTP endpoints, or email addresses.
3. Message is sent to a SQS queue and then replicated and pushed to multiple Amazon SNS topics.
4. Message is sent to a SQS queue and then replicated and pushed to multiple Amazon SQS queues.

Answer 19

1. A publisher sends same message to multiple SNS topics or SQS queues
2. Amazon SNS message is sent to a topic and then replicated and pushed to multiple Amazon SQS queues, HTTP endpoints, or email addresses.
3. Message is sent to a SQS queue and then replicated and pushed to multiple Amazon SNS topics.
4. Message is sent to a SQS queue and then replicated and pushed to multiple Amazon SQS queues.

Question 20

You are the solution architect of a financial services company. You are planning to use Amazon SQS while designing a distributed trading application. Key functional requirements pertaining to message queue are: processing of the messages in a sequential order, message should be processed only once and there should not be duplicate messages in the queue. How will you ensure the above requirements? Choose 3 options.

1. Use SQS Standard Queues.
2. Use SQS FIFO queues.
3. Use SWF FIFO.
4. Enable content-based deduplication.
5. Explicitly provide the message deduplication ID (or view the sequence number) for the message.

Answer 20

1. Use SQS Standard Queues.
2. Use SQS FIFO queues.
3. Use SWF FIFO.
4. Enable content-based deduplication.
5. Explicitly provide the message deduplication ID (or view the sequence number) for the message.

Question 21

You are designing a stock trading application. Your design includes using SQS for receiving trade confirmation messages from third party systems. You want to have the ability to isolate messages that can’t be processed correctly to determine why their processing didn’t succeed. How can you achieve this?

1. Map the Standard or FIFO Queue to S3 to store the exception messages.
2. Create a logic in message processing program to store the exception messages in DynamoDB.
3. Create an Amazon SQS Dead Letter Queue
4. Create an Amazon SQS Exception Queue

Answer 21

1. Map the Standard or FIFO Queue to S3 to store the exception messages.
2. Create a logic in message processing program to store the exception messages in DynamoDB.
3. Create an Amazon SQS Dead Letter Queue
4. Create an Amazon SQS Exception Queue

Question 22

You want to offer an online photo processing services for consumers. Users can upload the photo to the website and specify different operations like redeye reduction, cropping, thumb nail creation, photo filter, contract, brightening etc. Users can submit from few to hundreds of photos at a time. Which AWS services you will use to build a scalable and reliable web application?

1. Webserver- EC2, Web Database – RDS, Photo Asynchronous processing – SQS- Lambda, Photo Storage- RDS
2. Webserver- EC2, Web Database – RDS, Photo Asynchronous processing – SWF- Lambda, Photo Storage- S3
3. Webserver- EC2, Web Database – RDS, Photo Asynchronous processing – SNS- Lambda, Photo Storage- S3
4. Webserver- EC2, Web Database – RDS, Photo Asynchronous processing – SQS- Lambda, Photo Storage- S3

Answer 22

1. Webserver- EC2, Web Database – RDS, Photo Asynchronous processing – SQS- Lambda, Photo Storage- RDS
2. Webserver- EC2, Web Database – RDS, Photo Asynchronous processing – SWF- Lambda, Photo Storage- S3
3. Webserver- EC2, Web Database – RDS, Photo Asynchronous processing – SNS- Lambda, Photo Storage- S3
4. Webserver- EC2, Web Database – RDS, Photo Asynchronous processing – SQS- Lambda, Photo Storage- S3

Question 23

You are using SQS FIFO queue in your web application for asynchronous processing of messages. While doing unit testing you notice that producer is sending the message to queue successfully but downstream functional steps to be executed on message processing is not getting executing completely and there is an exception in the logs. After doing debugging you notice that at first, consumer program is picking up each unique message and then that message again reappears in the queue after the visibility time set of 5 minutes. Then that reappeared message is again picked up by the consumer program and reappears again. What could be the reason?

1. Visibility time of 5 mts is less than the time required by consumer program to process the message.
2. Message processing is failing because of which message reappears in the queue as consumer program is not deleting it from queue.
3. Message processing is successful but consumer program is not deleting the message from the queue.
4. Producer is sending duplicate messages into the queue.

Answer 23

1. Visibility time of 5 mts is less than the time required by consumer program to process the message.
2. Message processing is failing because of which message reappears in the queue as consumer program is not deleting it from queue.
3. Message processing is successful but consumer program is not deleting the message from the queue.
4. Producer is sending duplicate messages into the queue.

Question 24

What does SWF stands for?

1. Synchronous Workflow
2. Simple Workflow
3. Simple Work Foundation
4. Synchronous Work Foundation

Answer 24

1. Synchronous Workflow
2. Simple Workflow
3. Simple Work Foundation
4. Synchronous Work Foundation

Question 25

What are benefits of SQS message Queues? Choose 4 1. Better performance 2. Increased Reliability and Resiliency 3. Cost Optimization 4. User Security 5. Granular Scalability 6. Simplified Decoupling

Answer 25

1. **Better performance** 2. **Increased Reliability and Resiliency** 3. Cost Optimization 4. User Security 5. **Granular Scalability** 6. **Simplified Decoupling**

Question 26

A manufacturing company is developing an application running on EC2 which processes messages uploaded on a SQS queue from their plants all over the country. During the beta testing phase you have scheduled the application to run only over the weekend with default settings of SQS queue. After running the beta testing for two weekends when you are doing the analysis of the results you notice that not all messages were processed by the application. What could be the possible reason? 1. The default visibility time of 30 sec is less than time taken to process the messages. 2. The SQS application default setting of short polling. 3. By default messages in SQS are retained for only 4 days. 4. The default (minimum) delay for a message is 0 seconds.

Answer 26

1. The default visibility time of 30 sec is less than time taken to process the messages. 2. The SQS application default setting of short polling. 3. **By default messages in SQS are retained for only 4 days.** 4. The default (minimum) delay for a message is 0 seconds.

Question 27

You are solution architect for a startup designing a SaaS Mortgage Application. There are multiple business process which you want to design as discrete distributed application interacting with each other. What are the different AWS services you can use to coordinate task across distributed application components? Choose 2. 1. Amazon SQS 2. Amazon SWF 3. Amazon Step Functions 4. Amazon MQ

Answer 27

1. Amazon SQS 2. **Amazon SWF** 3. **Amazon Step Functions** 4. Amazon MQ

Question 28

You are using SQS FIFO queue in your web application for asynchronous processing of messages. While doing unit testing you notice that producer is sending the message to queue successfully, downstream functional steps to be executed on message processing is also getting executed successfully. After doing debugging you notice that consumer program is picking up each unique message and then that message reappears in the queue after the visibility time set of 5 minutes. Then that message is again picked up by the consumer program. What could be the reason? 1. Visibility time of 5 mts is less than the time required by consumer program to process the message. 2. Message processing is failing because of which message reappears in the queue as consumer program is not deleting it from queue. 3. Message processing is successful but consumer program is not deleting the message from the queue. 4. Producer is sending duplicate messages into the queue.

Answer 28

1. Visibility time of 5 mts is less than the time required by consumer program to process the message. 2. Message processing is failing because of which message reappears in the queue as consumer program is not deleting it from queue. 3. **Message processing is successful but consumer program is not deleting the message from the queue.** 4. Producer is sending duplicate messages into the queue.

Question 29

You are an architect for an ecommerce application. You are using SQS standard queue to receive order message and each order message is processed by a consumer lambda program which send email confirmation to the user. Lately you have been observing few instances of duplicate confirmation email messages being sent to the customers. You cannot compromise on the throughput of the queue. What changes you can make in the architecture to solve this duplicate message processing? 1. Decrease the visibility timeout period of the queue. 2. Convert standard queue to FIFO queue which has features to remove duplicate messages in the queue. 3. Have unique identifier in the message attribute and consumer lambda program use DynamoDB to keep track of them in establishing which message process are in progress, and which are complete. Check against before processing each message to check if the message is already processed or not. 4. Use delay queue.

Answer 29

1. Decrease the visibility timeout period of the queue. 2. Convert standard queue to FIFO queue which has features to remove duplicate messages in the queue. 3. **Have unique identifier in the message attribute and consumer lambda program use DynamoDB to keep track of them in establishing which message process are in progress, and which are complete. Check against before processing each message to check if the message is already processed or not.** 4. Use delay queue.

Question 30

You have a web app that lets users upload images and use them online. Each image requires resizing and encoding before it can be published. The web app runs on EC2 instances in a Dynamic Auto Scaling group based on CPU utilization that is configured to handle your typical upload rates. Unhealthy instances are terminated and replaced to maintain current instance levels at all times. The app places the raw bitmap data of the images in an Amazon SQS queue for processing. There are fleet of EC2 instance acting as worker program polling the SQS queue to processes the images and then publishes the processed images where they can be viewed by users. These consumer fleet of EC2 instance also has dynamic auto scaling policy. What is the benefit of using SQS in this architecture design? Choose 3. 1. Better performance by giving option of horizontal scaling of processing EC2 instances 2. Simplified Decoupling and asynchronous processing. 3. Increased Reliability 4. Simplified Decoupling and synchronous processing.

Answer 30

1. **Better performance by giving option of horizontal scaling of processing EC2 instances** 2. **Simplified Decoupling and asynchronous processing.** 3. **Increased Reliability** 4. Simplified Decoupling and synchronous processing.

Question 31

You have a web app that lets users upload images and use them online. Each image requires resizing and encoding before it can be published. The web app runs on EC2 instances in a Dynamic Auto Scaling group based on CPU utilization that is configured to handle your typical upload rates. Unhealthy instances are terminated and replaced to maintain current instance levels at all times. The app places the raw bitmap data of the images in an Amazon SQS queue for processing. There are fleet of EC2 instance acting as worker program polling the SQS queue to processes the images and then publishes the processed images where they can be viewed by users. These consumer fleet of EC2 instance also has dynamic auto scaling policy. The consumer EC2 instances are scaled up and down based on auto scale policy for the purposes of processing messages from an SQS queue. How will you configure the auto dynamic scaling policy? Choose 2. 1. A custom metric, number of messages in the queue, to send to Amazon CloudWatch that measures the number of messages in the queue per EC2 instance in the Auto Scaling group. 2. A target tracking policy that configures your Auto Scaling group to scale based on the custom metric and a set target value, number of messages in the queue per instance. CloudWatch alarms invoke the scaling policy. 3. A custom metric, backlog per instance, to send to Amazon CloudWatch that measures the number of messages in the queue per EC2 instance in the Auto Scaling group. 4. A target tracking policy that configures your Auto Scaling group to scale based on the custom metric and a set target value, acceptable backlog per instance. CloudWatch alarms invoke the scaling policy.

Answer 31

1. A custom metric, number of messages in the queue, to send to Amazon CloudWatch that measures the number of messages in the queue per EC2 instance in the Auto Scaling group. 2. A target tracking policy that configures your Auto Scaling group to scale based on the custom metric and a set target value, number of messages in the queue per instance. CloudWatch alarms invoke the scaling policy. 3. **A custom metric, backlog per instance, to send to Amazon CloudWatch that measures the number of messages in the queue per EC2 instance in the Auto Scaling group.** 4. **A target tracking policy that configures your Auto Scaling group to scale based on the custom metric and a set target value, acceptable backlog per instance. CloudWatch alarms invoke the scaling policy.**

Question 32

Which are the two service provided by AWS for workflow implementation? 1. Simple Workflow Service (SWF) 2. Step Functions 3. API Gateway 4. SQS

Answer 32

1. **Simple Workflow Service (SWF)** 2. **Step Functions** 3. API Gateway 4. SQS

Question 33

You are learning AWS by watching tutorial videos which are in English. To test your learning you want to create a PoC application which will take a video file as an input and generate subtitles in Spanish. The system will receive a video input, extract the audio track, transcribe it, and generate different subtitle files for your video. Your initial core design is to use: * Amazon Elastic Transcoder to extract the audio from the video * Amazon Transcribe to convert the audio to text * Amazon Translate to achieve fast, high-quality language translation You will also include a workflow management component which will coordinate components and steps through the functions of your application. What are other services you will use to design a cost optimized PoC application? 1. S3, Lambda, Cognito, DynamoDB 2. S3, Lambda, Step functions, Cognito, DynamoDB 3. S3, EC2, Step functions, Cognito, DynamoDB 4. S3, ECS, Step functions, Cognito, DynamoDB

Answer 33

1. S3, Lambda, Cognito, DynamoDB 2. **S3, Lambda, Step functions, Cognito, DynamoDB** 3. S3, EC2, Step functions, Cognito, DynamoDB 4. S3, ECS, Step functions, Cognito, DynamoDB

Question 34

Which of the following are type of actor in SWF? Choose 3. 1. Workflow starters 2. Deciders 3. Task worker 4. Activity workers

Answer 34

1. **Workflow starters** 2. **Deciders** 3. Task worker 4. **Activity workers**

Question 35

While designing a web application to process customer order you have followed best practices as depicted in the diagram below. Your design includes implementing load balancing, dynamic scaling across multiple Availability Zones and persisting orders in a Multi-AZ Amazon RDS database instance. The application receives and persisting the order data, as well as scales with increases in traffic for popular items. One potential point of vulnerability in the order processing workflow is in saving the order in the database. The business expects that every order should be persisted into the database. However, any potential deadlock, race condition, or network issue could cause the persistence of the order to fail. Then, the order is lost with no recourse to restore the order. What change you can make in your architecture to address this issue? 1. Change the family of web server EC2 instance to higher family with more CPU, memory and use Provisioned IOPS SSD backed EBS volumes. 2. Change the RDS storage to use Provisioned IOPS SSD. Provision a high IOPS and storage for database. 3. Use SQS queue to isolates the processing logic into its own component and runs it in a separate process from the web application. 4. All of the above.

Answer 35

1. Change the family of web server EC2 instance to higher family with more CPU, memory and use Provisioned IOPS SSD backed EBS volumes. 2. Change the RDS storage to use Provisioned IOPS SSD. Provision a high IOPS and storage for database. 3. **Use SQS queue to isolates the processing logic into its own component and runs it in a separate process from the web application.** 4. All of the above.

Question 36

Which AWS service is appropriate for creating, publishing, maintaining, monitoring, and securing REST and WebSocket APIs at any scale? 1. AWS ELB 2. Amazon API Gateway 3. AWS AppSync 4. Amazon Cognito

Answer 36

1. AWS ELB 2. **Amazon API Gateway** 3. AWS AppSync 4. Amazon Cognito

Question 37

You are a solution architect for a mortgage processing SaaS application. You were having a design discussion with business analyst to break down the mortgage process from loan application to disbursal of money in multiple workflows. You made a list of multiple workflows which needs to interact with each other. How should you design these workflows in Amazon SWF? 1. Collapse all multiple workflows into a single workflow and place it in a single domain, as workflows cannot interact across domains. 2. Place each workflow in its own individual separate domain and design the workflows to interact across the domains. 3. You cannot use SWF as workflow cannot interact with each other in SWF. 4. Place the workflows which needs to interact with each other in a same domain, as workflows cannot interact across domains.

Answer 37

1. Collapse all multiple workflows into a single workflow and place it in a single domain, as workflows cannot interact across domains. 2. Place each workflow in its own individual separate domain and design the workflows to interact across the domains. 3. You cannot use SWF as workflow cannot interact with each other in SWF. 4. **Place the workflows which needs to interact with each other in a same domain, as workflows cannot interact across domains.**

Question 38

What are the different types of Amazon SWF tasks? Choose 3. 1. Notification task 2. Activity task 3. Lambda task 4. Decision task

Answer 38

1. Notification task 2. **Activity task** 3. **Lambda task** 4. **Decision task**

Question 39

Amazon SWF provides you with the feature of Signals that enables you to inject information into a running workflow execution. This helps in scenarios where you might want to add information to a running workflow execution to let it know that something has changed or to inform it of an external event. Which of the following is not an appropriate use case for using this feature? 1. For cases in which workflow has to be cancelled. (e.g., the order was cancelled by the customer ). 2. Pausing workflow executions from progressing until a signal is received (e.g., waiting for an inventory shipment). 3. Providing information to a workflow execution that might affect the logic of how deciders make decisions. This is useful for workflows affected by external events (e.g., trying to finish the sale of a stock after the market closes). 4. Updating a workflow execution when you anticipate that changes might occur (e.g., changing order quantities after an order is placed and before it ships).

Answer 39

1. **For cases in which workflow has to be cancelled. (e.g., the order was cancelled by the customer ).** 2. Pausing workflow executions from progressing until a signal is received (e.g., waiting for an inventory shipment). 3. Providing information to a workflow execution that might affect the logic of how deciders make decisions. This is useful for workflows affected by external events (e.g., trying to finish the sale of a stock after the market closes). 4. Updating a workflow execution when you anticipate that changes might occur (e.g., changing order quantities after an order is placed and before it ships).

Question 40

Which AWS service enables developers to manage and synchronize mobile app data in real time across devices and users, but still allows the data to be accessed and altered when the mobile device is in an offline state? 1. Amazon API Gateway 2. Amazon Cognito 3. AWS DataSync 4. AWS AppSync

Answer 40

1. Amazon API Gateway 2. Amazon Cognito 3. AWS DataSync 4. **AWS AppSync**

Question 41

You run an online photo editing website for two type of members: free members and fee paying premium members. The set of editing requests and photos is placed asynchronously in a SQS queue which is then processed by EC2 instances in an auto scaling group. How can you modify the architecture to ensure that your premium members editing upload get higher request than free member photo uploads? 1. Set the *message timer* attribute for free member’s message so that those category messages are delayed for processing. 2. Create two queues, one for premium members and one for free members editing task. EC2 processing program should poll premium member’s queue first and only if message request is empty then it should poll the free member’s queue. 3. Set the priority in a message attribute and EC2 program will process the message accordingly. 4. Create a separate delay queue for free member’s messages.

Answer 41

1. Set the *message timer* attribute for free member’s message so that those category messages are delayed for processing. 2. **Create two queues, one for premium members and one for free members editing task. EC2 processing program should poll premium member’s queue first and only if message request is empty then it should poll the free member’s queue.** 3. Set the priority in a message attribute and EC2 program will process the message accordingly. 4. Create a separate delay queue for free member’s messages.

Question 42

What are difference between Standard and Express workflows in AWS Step Functions? Choose 2. 1. Standard Workflows are ideal for long-running, durable, and auditable workflows. Express Workflows are ideal for high-volume, event-processing workloads. 2. Standard Workflows employ an at-most-once model. Express Workflows employ an at-least-once model 3. Express Workflows are ideal for long-running, durable, and auditable workflows. Standard Workflows are ideal for high-volume, event-processing workloads. 4. Express Workflows employ an at-most-once model. Standard Workflows employ an at-least-once model

Answer 42

1. **Standard Workflows are ideal for long-running, durable, and auditable workflows. Express Workflows are ideal for high-volume, event-processing workloads.** 2. **Standard Workflows employ an at-most-once model. Express Workflows employ an at-least-once model** 3. Express Workflows are ideal for long-running, durable, and auditable workflows. Standard Workflows are ideal for high-volume, event-processing workloads. 4. Express Workflows employ an at-most-once model. Standard Workflows employ an at-least-once model

Question 43

What are different states you can define in an AWS Step Function? Choose 3. 1. Cancel, Retry 2. Task, Choice, Pass 3. Fail/Succeed, Wait 4. Parallel, Map

Answer 43

1. Cancel, Retry 2. **Task, Choice, Pass** 3. **Fail/Succeed, Wait** 4. **Parallel, Map**

Question 44

Which structured language is used to define your AWS Step function state machine? 1. Amazon Step Function Language 2. Amazon States Language 3. Amazon Step Function Policy 4. Amazon Step Function Access Control Language

Answer 44

1. Amazon Step Function Language 2. **Amazon States Language** 3. Amazon Step Function Policy 4. Amazon Step Function Access Control Language

Question 45

Which of the following is not a use case for AWS Step functions? 1. Data processing: consolidate data from multiple databases into unified reports, refine and reduce large data sets into useful formats, or coordinate multi-step analytics and machine learning workflows 2. Container orchestration service : run, scale, and secure Docker container applications 3. DevOps and IT automation: build tools for continuous integration and continuous deployment, or create event-driven applications that automatically respond to changes in infrastructure 4. E-commerce: automate mission-critical business processes, such as order fulfillment and inventory tracking 5. Web applications: implement robust user registration processes and sign-on authentication

Answer 45

1. Data processing: consolidate data from multiple databases into unified reports, refine and reduce large data sets into useful formats, or coordinate multi-step analytics and machine learning workflows 2. **Container orchestration service : run, scale, and secure Docker container applications** 3. DevOps and IT automation: build tools for continuous integration and continuous deployment, or create event-driven applications that automatically respond to changes in infrastructure 4. E-commerce: automate mission-critical business processes, such as order fulfillment and inventory tracking 5. Web applications: implement robust user registration processes and sign-on authentication

Question 46

You are designing an online mortgage loan application based on Serverless microservices based architecture. The business logic for different application processing steps will be microservices developed using AWS Lambda. The data tier will comprise of S3 and DynamoDB. Users will also access this application using native mobile application running on their smartphones and will be authenticated using Amazon Cognito. Which AWS service you will use to expose the microservices as well as defined RESTful APIs and the service should scale with traffic? 1. Cognito 2. Network Load Balancer 3. API Gateway 4. Application Load Balancer

Answer 46

1. Cognito 2. Network Load Balancer 3. **API Gateway** 4. Application Load Balancer

Question 47

You run an online photo editing website for two type of members: free members and fee paying premium members. The set of editing requests and photos is placed asynchronously in a SQS queue which is then process by worked EC2 instances in an auto scaling group. The architecture has two SQS queues, one for premium members and one for free members editing task. You have on-demand EC2 instances in an auto scale group to process the messages in the premium members queue and spot instances for processing the message from free member queue. At times spot instances are terminated by AWS. What will happen to messages which are in-process by those terminated instances? 1. The message will be deleted by SQS. 2. The message will be deleted by the terminated instance and will not appear in the queue. 3. The message will be visible immediately in the queue and picked up for processing by other live spot instance. 4. The message will be visible in the queue after the visibility time is over and picked up for processing by other live spot instance.

Answer 47

1. The message will be deleted by SQS. 2. The message will be deleted by the terminated instance and will not appear in the queue. 3. The message will be visible immediately in the queue and picked up for processing by other live spot instance. 4. **The message will be visible in the queue after the visibility time is over and picked up for processing by other live spot instance.**

Question 48

Which type of Step function workflow you will use for use cases like streaming data processing, IoT data ingestion, mobile backend, and other high-throughput use-cases? 1. Standard workflow 2. Express workflow 3. Streaming workflow 4. Serverless workflow

Answer 48

1. Standard workflow 2. **Express workflow** 3. Streaming workflow 4. Serverless workflow

Question 49

Which type of Step function workflow you will use for orchestrating non-idempotent actions, such as starting an Amazon EMR cluster or processing payments. ? 1. Standard workflow 2. Express workflow 3. Streaming workflow 4. Serverless workflow

Answer 49

1. **Standard workflow** 2. Express workflow 3. Streaming workflow 4. Serverless workflow

Question 50

What are difference between Amazon SWF vs. AWS Step Functions? Choose 2. 1. AWS SWF provides a more productive and agile approach to coordinating application components using visual workflows with writing state machines in declarative JSON. 2. Amazon Step Functions gives you complete control over your orchestration logic, but increases the complexity of developing applications. You may write decider programs in the programming language of your choice, or you may use the Flow framework. 3. Amazon SWF gives you complete control over your orchestration logic, but increases the complexity of developing applications. You may write decider programs in the programming language of your choice, or you may use the Flow framework. 4. AWS Step Functions provides a more productive and agile approach to coordinating application components using visual workflows with writing state machines in declarative JSON.

Answer 50

1. AWS SWF provides a more productive and agile approach to coordinating application components using visual workflows with writing state machines in declarative JSON. 2. Amazon Step Functions gives you complete control over your orchestration logic, but increases the complexity of developing applications. You may write decider programs in the programming language of your choice, or you may use the Flow framework. 3. **Amazon SWF gives you complete control over your orchestration logic, but increases the complexity of developing applications. You may write decider programs in the programming language of your choice, or you may use the Flow framework.** 4. **AWS Step Functions provides a more productive and agile approach to coordinating application components using visual workflows with writing state machines in declarative JSON.**

Question 51

Which of the following is not a correct scenario for using SNS? Choose 2. 1. Use Amazon SNS to push targeted news headlines to subscribers by email or SMS. 2. An application that sends a message to an Amazon SQS queue whenever an order is placed for a product. Then, the Amazon SNS topics that are subscribed to that queue would receive identical notifications for the new order. 3. Use Amazon SNS for sending notifications to an app, indicating that an update is available. The notification message can include a link to download and install the update. 4. Use Amazon SNS for authenticating mobile app users with Cognito. 5. An application that sends an Amazon SNS message to a topic whenever an order is placed for a product. Then, the Amazon SQS queues that are subscribed to that topic would receive identical notifications for the new order.

Answer 51

1. Use Amazon SNS to push targeted news headlines to subscribers by email or SMS. 2. **An application that sends a message to an Amazon SQS queue whenever an order is placed for a product. Then, the Amazon SNS topics that are subscribed to that queue would receive identical notifications for the new order.** 3. Use Amazon SNS for sending notifications to an app, indicating that an update is available. The notification message can include a link to download and install the update. 4. **Use Amazon SNS for authenticating mobile app users with Cognito.** 5. An application that sends an Amazon SNS message to a topic whenever an order is placed for a product. Then, the Amazon SQS queues that are subscribed to that topic would receive identical notifications for the new order.

Question 52

How can you improve the latency of requests to your API Gateway and also reduce the number of calls made to your API endpoint? 1. Use ElastiCache with API Gateway 2. Enable API caching in the API Gateway setting 3. Use CloudFront with API Gateway 4. Configuring API-level and Stage-Level Throttling in a Usage Plan

Answer 52

1. Use ElastiCache with API Gateway 2. **Enable API caching in the API Gateway setting** 3. Use CloudFront with API Gateway 4. Configuring API-level and Stage-Level Throttling in a Usage Plan

Question 53

Which of the following are features of Amazon SNS? Choose 4. 1. Provides developers with a highly scalable, flexible, and cost-effective capability to publish messages from an application and immediately deliver them to subscribers or other applications 2. Follows the “publish-subscribe” (pub-sub) messaging paradigm, with notifications being delivered to clients using a “poll” mechanism that eliminates the need to periodically “push” new information and updates. 3. Follows the “publish-subscribe” (pub-sub) messaging paradigm, with notifications being delivered to clients using a “push” mechanism that eliminates the need to periodically check or “poll” for new information and updates. 4. A subscriber sends messages to topics that they have created or to topics they have permission to publish to. 5. A publisher sends messages to topics that they have created or to topics they have permission to publish to. 6. Subscribers receive all messages published to the topics to which they subscribe, and all subscribers to a topic receive the same messages.

Answer 53

1. **Provides developers with a highly scalable, flexible, and cost-effective capability to publish messages from an application and immediately deliver them to subscribers or other applications** 2. Follows the “publish-subscribe” (pub-sub) messaging paradigm, with notifications being delivered to clients using a “poll” mechanism that eliminates the need to periodically “push” new information and updates. 3. **Follows the “publish-subscribe” (pub-sub) messaging paradigm, with notifications being delivered to clients using a “push” mechanism that eliminates the need to periodically check or “poll” for new information and updates.** 4. A subscriber sends messages to topics that they have created or to topics they have permission to publish to. 5. **A publisher sends messages to topics that they have created or to topics they have permission to publish to.** 6. **Subscribers receive all messages published to the topics to which they subscribe, and all subscribers to a topic receive the same messages.**

Question 54

You are the solution architect for an ecommerce company. There are regular flash discounts and festivals discount offered which leads to sudden burst in orders at an unpredictable magnitude and many time more than off discount period. How can you ensure none of the customer order is lost without impacting performance, scalability, and resiliency? 1. Increase the minimum fleet of servers saving the customers’ orders. 2. Have an SQS queue for customer orders and fleet of EC2 instances in auto scale group to process the order. 3. Increase the performance and capacity of database. 4. Use lambda instead of EC2 for processing the customer order.

Answer 54

1. Increase the minimum fleet of servers saving the customers’ orders. 2. **Have an SQS queue for customer orders and fleet of EC2 instances in auto scale group to process the order.** 3. Increase the performance and capacity of database. 4. Use lambda instead of EC2 for processing the customer order.

Question 55

How is Amazon SNS different from Amazon SQS? Choose 2. 1. Amazon SNS allows applications to send time-critical messages to multiple subscribers through a “push” mechanism, eliminating the need to periodically check or “poll” for updates. 2. Amazon SQS allows applications to send time-critical messages to multiple subscribers through a “push” mechanism, eliminating the need to periodically check or “poll” for updates. 3. Amazon SQS is a message queue service used by distributed applications to exchange messages through a polling model, and can be used to decouple sending and receiving components. 4. Amazon SNS is a message queue service used by distributed applications to exchange messages through a polling model, and can be used to decouple sending and receiving components.

Answer 55

1. **Amazon SNS allows applications to send time-critical messages to multiple subscribers through a “push” mechanism, eliminating the need to periodically check or “poll” for updates.** 2. Amazon SQS allows applications to send time-critical messages to multiple subscribers through a “push” mechanism, eliminating the need to periodically check or “poll” for updates. 3. **Amazon SQS is a message queue service used by distributed applications to exchange messages through a polling model, and can be used to decouple sending and receiving components.** 4. Amazon SNS is a message queue service used by distributed applications to exchange messages through a polling model, and can be used to decouple sending and receiving components.

Question 56

Which of the following Apps will not be suitable to use AWS AppSync? 1. Gaming apps with real-time scoreboards, News feeds and financial data 2. Customer service dashboards, Social Media with content feeds and search/discovery/messaging 3. Shared wallet, travel or itinerary tracking with offline usage 4. Business Intelligence interactive dashboard with drill down capability 5. Dating apps with likes, messaging and geo/proximity awareness 6. Field service apps that need to allow for querying and CRUD operations, even when disconnected 7. Chat apps, including presence indicators and conversation history

Answer 56

1. Gaming apps with real-time scoreboards, News feeds and financial data 2. Customer service dashboards, Social Media with content feeds and search/discovery/messaging 3. Shared wallet, travel or itinerary tracking with offline usage 4. **Business Intelligence interactive dashboard with drill down capability** 5. Dating apps with likes, messaging and geo/proximity awareness 6. Field service apps that need to allow for querying and CRUD operations, even when disconnected 7. Chat apps, including presence indicators and conversation history

Question 57

Which AWS Service is a fully managed serverless GraphQL service for real-time data queries, synchronization, communications and offline programming features? 1. Amazon Athena 2. AWS Amplify 3. AWS DataSync 4. AWS AppSync

Answer 57

1. Amazon Athena 2. AWS Amplify 3. AWS DataSync 4. **AWS AppSync**

Question 58

Which of the following are not features of AppSync? Choose 2. 1. Uses GraphQL, a data language that enables client apps to fetch, change and subscribe to data from servers. 2. Best for creating RESTful APIs using either HTTP APIs (Preview) or REST APIs. 3. Let’s you specify which portions of your data should be available in a real-time manner using GraphQL Subscriptions. 4. Provides a queryable on-device DataStore for web, mobile and IoT developers with a local-first and familiar programming model to interact with data seamlessly whether you’re online or offline. 5. Makes it easy for developers to publish, maintain, monitor, secure, and operate APIs at any scale. 6. Gives client applications the ability to specify data requirements with GraphQL so that only the needed data is fetched, allowing for both server and client filtering. 7. Server-side data caching capabilities reduce the need to directly access data sources by making data available in high speed in-memory managed caches, delivering data at low latency.

Answer 58

1. Uses GraphQL, a data language that enables client apps to fetch, change and subscribe to data from servers. 2. **Best for creating RESTful APIs using either HTTP APIs (Preview) or REST APIs.** 3. Let’s you specify which portions of your data should be available in a real-time manner using GraphQL Subscriptions. 4. Provides a queryable on-device DataStore for web, mobile and IoT developers with a local-first and familiar programming model to interact with data seamlessly whether you’re online or offline. 5. **Makes it easy for developers to publish, maintain, monitor, secure, and operate APIs at any scale.** 6. Gives client applications the ability to specify data requirements with GraphQL so that only the needed data is fetched, allowing for both server and client filtering. 7. Server-side data caching capabilities reduce the need to directly access data sources by making data available in high speed in-memory managed caches, delivering data at low latency.

Question 59

Your company is planning to migrate portfolio of distributed applications to AWS. Currently ActiveMQ is the message broker used between in-premise applications. Which AWS service you should use to replace the message broker component of the architecture? 1. Amazon SQS 2. Amazon SNS 3. Amazon MQ 4. Amazon ActiveMQ

Answer 59

1. Amazon SQS 2. Amazon SNS 3. **Amazon MQ** 4. Amazon ActiveMQ