What I have learned about Applications on AWS

Amazon-Web-Services · 02 May 2022

This is the tenth post of content for preparing yourself for becoming an AWS Solutions Architect Associate.

In this post, we are going to focus on application features within AWS.

As I have done previously let’s look at the similarities and differences to the closest equivalent in Azure. As I go through this section, I will point out some of the similar platforms.

SQS - Simple Queue Service

Oldest service in AWS
Message queue service
Temporary repository for processing messages
Similar to Azure messaging service
Decoupled of the applications, compute, or storage services.
256kb of text max to store in SQS. Larger messages are stored in S3.
Retrieved with SQS API

Types of SQS queues

Standard - nearly unlimited transactions per second
- Multiples copies and out of order messages delivered, so application must be able to handle this
FIFO - in sequence, only delivered once
- Limited to 300 transitions per second
Pull-based service, EC2 instance must be pulling queues
Messages kept in queue 1 minute to 14 days. Default is 4 days.
Visibility timeout - if job is not processed within the time period, the message becomes visible again. Max is 12 hours.
Long polling - won’t return a response to EC2 until a message arrives to save cost.

Simple workflow service

Different from SQS
Coordinate work across multiple services and processing steps
Applications and manual processes with executable code. Similar to Amazon ordering.
Example use case is Warehouse orders.
Workflow execution is up to one year
Task oriented API
Tasks assigned only once and never duplicated
Keeps track of all tasks and events

SWF Actors

Starters - initiate the workflow
Deciders - flow of activities
Activity workers - carry out the tasks

Simple notification service

SNS - web service to send notifications from the cloud
Push notifications to mobile devices
Any HTTP endpoint
SMS
Topics - allows subscribers to multiple users
Redundantly stored across AZ
No polling
PAYG
Web based management console
Similar to Azure Messaging Service

Elastic transcoder

Converting media files to different formats to play on different devices

Pay based on minutes and resolution

API gateway

Fully managed service
Doorway into AWS - front door to applications to access data and business logic
Usually to communicate with Lambda functions
Similar to Azure APIM
Restful API from HTTP
Scales effortlessly and automatically with traffic
Runs efficiently with low choose
Throttle requests to prevent attacks

Steps to deploy:

Define an API
Define resources and nested resources (URL paths)
For each resource:
- HTTP methods
- Security settings
- Targets
Set request and response

API caching

Reduces the number of calls for a response

Cross origin resource policy

same origin policy. Protects against XSS by making sure that the web URL is from the same origin

CORS

relaxes the same origin policy by allowing resource restriction on a web page to be requested from another domain
Origin resource error means that CORS is not enabled
Enforced by the browser

Kinesis

Streaming data continuous from thousands of resources
Small sizes of data (in KB)
Transactional data
- Purchases
- Stock prices
- Game data (as the gamer plays, levels, etc)
- Social network data
- Geospatial data (where you are in a map, ex: Uber)
- IoT sensor data
Platform to send the streaming data. Similar to Azure Streaming Service or even IoT Hub.

Three types of Kinesis:

Kinesis Streams - Producers from multiple sources. Stores data 24 hours to 7 days. Data contained in individual Shards depending on the type of data. EC2 instances are the producers that analyze the data. Present the analyzed data to a storage account
Kinesis Firehose - No persistent storage, must do something with the data as it comes in and outputs it to a storage account.
Kinesis Analytics - Works with Streams and Firehose. Analyzes data on the fly to a storage account.

Web Identity Federation and Cognito

Web Identity Federation - access to AWS resources using web-based identity providers (Amazon, Facebook, Google)
Amazon Cognito is AWS’ Web Identity Federation
- Acts as the identity broker
- Synchronizes on multiple devices
- Recommended for all mobile application development
- Brokers between the App and the identity provider to provide a seamless experience
User Pools - sign in directly to Cognito. Json web token (JWT) for successful authentication. User names and passwords.
Identity Pools - provide temporary AWS credentials. Grants the AWS IAM role to access AWS resources. Granting of access and authorization to resources with the JWT.
Push synchronization sends an SNS to all devices to synchronize any changes in Cognito.

Event Processing Patterns

Event-drive architecture - Pub/Sub messaging - decoupling systems running in response to events. ex: SNS topics.
- Publisher - Messages - SNS topic - Subscriber
Dead-letter Queue (DLQ) - unclaimed messages
- SNS - held for further analysis.
- SQS - exceeds the maxReceiveCount
- Lambda functions - failed runtimes in asynchronous functions
Fanout Pattern - use SNS topics and replicates to multiple SQS queues for multiple subscribers.
S3 Event Notifications - can be sent to multiple subscribers and destinations, such as SQS, SNS, and Lambda functions. Different events are:
- Object created events
- Object removed
- Object restored
- RRS Object lost
- Replication

I hope that you are enjoying this information so far. It is helping me to continue to comprehend these services as I prepare for the exam myself. Thank you very much.

Reference links:

What I’ve Learned about IAM on AWS

https://captainhyperscaler.github.io/amazon-web-services/2022/03/20/aws-iam

What I’ve Learned about S3 on AWS

https://captainhyperscaler.github.io/amazon-web-services/2022/03/20/aws-s3

What I’ve Learned about EC2 on AWS

https://captainhyperscaler.github.io/amazon-web-services/2022/03/22/aws-ec2

What I’ve Learned about EBS on AWS

https://captainhyperscaler.github.io/amazon-web-services/2022/03/22/aws-ebs

What I’ve Learned about Cloudwatch on AWS

https://captainhyperscaler.github.io/amazon-web-services/2022/03/22/aws-cloudwatch

What I’ve Learned about RDS on AWS