SQS & SNS & SWF

Question 1

SQS Visibility Time Out

Answer 1

12 Hrs

Question 2

FIFO

Answer 2

Does not Offer FIFO. First In First Out. Although in the latest update it does.

Question 3

SQS Message Delivery

Answer 3

Will attempt at least once to deliver all message in it’s queues.

Your system should be able to handle the same message multiple times.

Question 4

SQS Max Size

Answer 4

256KB

Question 5

SQS Pricing Model

Answer 5

1st million SQS requests per month are free.

50 cent per million requests per month afterwards.

Question 6

SQS How many messages can a request send.

Answer 6

1-10 messages with a max size of 256KB

Question 7

SQS How is it billed

Answer 7

Billed by 64KB chunk.

Question 8

SQS Message order

Answer 8

Any order and received multiple times.

Question 9

SQS Default Visibility Time Out

Answer 9

30 Seconds.

Can be extended by using the ChangeMessageVisibility Action.

Question 10

SQS Max Time Out. Maximum Visibility.

Answer 10

12 Hours

Question 11

SQS Long Polling

Answer 11

Doesn’t return a response until a message arrives in the Queue.

Cheaper

Times out in 20 seconds.

Question 12

SQS Fanning Out

Answer 12

SNS topic is created. Then SQS queues the SNS topic. Messages sent to SNS will be fanned out to SQS Queues.

Question 13

Maximum Retention Period

Answer 13

14 Days.

Question 14

What is SNS

Answer 14

Simple Notification Service. WS sends notification from the cloud.

No polling and pushes notifications to subscribers.

Question 15

SNS Topic

Answer 15

Access point allowing recepients to subscribe to copies of the same message. SNS formats themessage to the platform.

Question 16

SNS Pricing Model

Answer 16

• 50¢ per million requests
• 6¢ per 100k HTTP
• 75¢ 100k messages over SMS
• $2 per 100k message over EMAIL

Question 17

SNS Protocols

Answer 17

HTTP(S),Email, SQS (Fanning), Application, Lambda

Question 18

What is SWF

Answer 18

WebService that coordinates multiple tasks across application components.

Consists of the following:
1- Domains
2- Workers
3- Deciders

Question 19

SWF Workers

Answer 19

Programs that interact with SWF to get tasks, process received tasks, and return results.

Question 20

SWF Decider

Answer 20

Program that controls coordination of tasks

Question 21

WorkFlow Maximum Timeout

Answer 21

1 year

Question 22

SWF vs SQS

Answer 22

Use SWF if it envolves Human Interaction (ie Warehouse example).

Maintains application state (SWF keeps track of all your tasks.)

Question 23

SQS Quiz Question: Polling is burning CPU Cycles and costing your company money. How do you reduce the costs?

Answer 23

Long Polling to 20 seconds. That way the queue holds on to a request for 20 seconds at a time rather than every 2 seconds before responding. 1 min = 3 responses otherwise 1 min = 30 responses.

Question 24

SQS: What Does ReceiveMessageWaitTime do?

Answer 24

set short and long polling

Question 25

SQS: What does ChangeMessageVisibility do?

Answer 25

used to request or extend more time before timeout.

Question 26

SNS - What command to use to get multiple device tokens

Answer 26

CreatePlatformEndpoint API