Application Integration

Question 1

Simple Notification Service (SNS)

Answer 1

set up, operate, and send notification from the cloud
Ex. send email notification when CloudWatch alarm is triggered

web service that makes it easy to set up, operate, and send notifications from the cloud
used for building and integrating loosely-coupled, distributed applications
provides instantaneous, push-based delivery (no polling)
uses simple APIs and easy integration w/ applications
offered under an inexpensive, pay-as-you-go model w/ no up-front costs

Question 2

Simple Queue Service (SQS)

Answer 2

messaging queue; store and forward patterns
Ex. building distributed / decoupled applications

web service that gives you access to message queues that store messages waiting to be processed
offers a reliable, highly-scalable, hosted queue for storing messages in transit between computers
used for distributed/decoupled applications
uses a message-oriented API
uses pull based (polling) not push based

Question 3

Simple Workflow Service (SWF)

Answer 3

need to support external processes or specialized execution logic
Ex. Human-enabled workflows like an order fulfilment system or for procedural requests
Note - older service; AWS recommends that for new applications customers consider Step Functions instead of SWF

web service that makes easy to coordinate work across distributed application components
create distributed asynchronous systems as workflows
supports both sequential and parallel processing
tracks the state of your workflow which you interact and update via API
best suited for human-enabled workflows like order fulfilment system or for procedural requests
AWS recommends that for new applications customers consider Step Functions instead of SWF
SWF enables applications for a range of use cases - media processing, web application back-ends, business process workflows, analytics pipelines, to be designed as a coordination of tasks

Question 4

Step Functions

Answer 4

out-of-the-box coordination of AWS service components with visual workflow
Ex. order processing workflow

relatively new service; kind of the “successor” to SWF
make it easy to coordinate the components of distributed applications as a series of steps in a visual workflow
you can quickly build and runs state machines to execute the steps of your application in a reliable and scalable fashion

How It Works:

1. define steps of your workflow in the JSON-based Amazon States Language. The visual console automatically graphs each step in the order of execution
2. start an execution to visualize and verify the steps of your application are operating as intended. the console highlights the real-time status of each step and provides a detailed history of every execution
3. AWS Step Functions operates and scales the steps of your application and underlying compute for you to help ensure your application executes reliably under increasing demand

Question 5

Asynchronous integration

Answer 5

form of loose coupling between services
This model is suitable for any interaction that does not need an immediate response and where an acknowledgement that a request has been registered will suffice
Amazon Simple Queue Service (SQS) and AWS Step Functions both provide asynchronous integration. SQS provides a durable message bus and Step Functions is an orchestrated workflow service.