AWS Cloud Developer: Messaging and Containers

Question 1

Differences between Notifications and Messages

Answer 1

Notifications are sent to Humans

Messaging occurs between internet-based devices and appliccations

Question 2

SNS -simple notification service

Answer 2

Amazon Simple Notification Service (or SNS) is a cloud service that allows you to send notifications to the users of your applications. SNS allows you to decouple the notification logic from being embedded in your applications and allows notifications to be published to a large number of subscribers.

Question 3

Features of SNS

Answer 3

SNS uses a publish/subscribe model.

SNS can publish messages to Amazon SQS queues, AWS Lambda functions, and HTTP/S webhooks.

Question 4

Which model is used by SNS

Answer 4

Publish/subscribe model

Users need to subscribe in order to receive notifications

Question 5

How are notifications sent to end users using SNS

Answer 5

Mobile push
text messages
email

Question 6

How many messages can one notification contain?

Answer 6

one message

Question 7

Can SnS be used to send messages to both people and applications?

Answer 7

Yes

Application-to-application messaging

Application-to-application messaging supports subscribers such as AWS Lambda functions, Amazon SQS queues, HTTP/S endpoints, and AWS Event Fork Pipelines. For more information, see Using Amazon SNS for application-to-application (A2A) messaging.

Application-to-person notifications

Application-to-person notifications provides user notifications to subscribers such as mobile applications, mobile phone numbers, and email addresses. For more information, see Using Amazon SNS for application-to-person (A2P) messaging.

Question 8

Queues

Answer 8

A queue is a data structure that holds requests called messages. Messages in a queue are commonly processed in order, first in, first out (or FIFO).

Messaging queues improve:

performance
scalability
user experience

Question 9

What type of processing does queuing support?

Answer 9

asynchronous processing

Question 10

SQS -Simple Queue Service

Answer 10

Amazon Simple Queue Service (SQS) is a fully managed message queuing service that allows you to integrate queuing functionality in your application. SQS offers two types of message queues: standard and FIFO.

Question 11

Features of SQS

Answer 11

send messages
store messages
receive messages

Question 12

How many messages can FIFO queues support?

Answer 12

FIFO queues support up to 300 messages per second.

Question 13

2 types of message queues

Answer 13

Standard and FIFO

Question 14

When to use a FIFO queue?

Answer 14

When ordering is important

Question 15

Main difference between FIFO and Standard queues?

Answer 15

FIFO queues guarantee the ordering of messages.

FIFO messages are processed exactly once

Standard queues offer best-effort ordering but no guarantees.

Standard queues deliver a message at least once, but occasionally more than one copy of a message is delivered.

Question 16

A container

Answer 16

A container consists of everything an application needs to run: the application itself and its dependencies (e.g. libraries, utilities, configuration files), all bundled into one package.

Each container is an independent component that can run on its own and be moved from environment to environment.

Question 17

Docker

Answer 17

A Docker container image is a lightweight, standalone, executable package of software that includes everything needed to run an application: code, runtime, system tools, system libraries and settings.

Question 18

Difference between Containers and Virtual Machines

Answer 18

Containers and virtual machines have similar resource isolation and allocation benefits, but function differently because containers virtualize the operating system instead of hardware. Containers are more portable and efficient.

Question 19

ECS Elastic Container Service

Answer 19

ECS is an orchestration service used for automating deployment, scaling, and managing of your containerized applications. ECS works well with Docker containers by:

launching and stopping Docker containers
scaling your applications
querying the state of your applications

Question 20

Which is the only container platform supported by Amazon ECS?

Answer 20

Docker

Question 21

Kubernetes

Answer 21

An orchestration service for docker containers