App Integration Flashcards
What is Event Bridge?
Event bridge uses events to connect application components
The 4 types of event sources are: AWS Services, Custom Apps, SaaS Apps, Microservices
What is Step Function?
Looks like a flow chart
Ie., can wait up to 356 days - inventory management could take ages so helps with real world interactions
or
If lambda took longer than 15 mins to run it would enter fail state because its the max length of time it should take
Can you do branches or loops within a Step Function?
Yes
Who puts messages into SQS queue
Producers
Who do producers send messages to?
Producers -> SQS -> consumer
One benefit of SQS and SNS is that
SQS decouples consumers and producers
SNS decouples publishers and subscribers
What is a Dead Letter Queue?
It could be something failed that a human looks at or something we set up to automatically
What is the idea of ‘fanout’ in SNS?
Fanout is when a message published to an SNS topic is replicated and pushed to multiple endpoints
How can you use SNS and SQS?
You could upload SNS ( a new image to process) this could fan out to 3 SQS queues and then EC2 could be processing and making EC2 thumbnails at same time lambda could be processing one of the sqs queues
Order (producer)
Chef (consumer)
What is App Sync?
App Sync is a managed Graph QL interface get or set aggregated data and display it in our apps
Used in things like social media
When should you use SNS and SQS?
If you need to make sure the message is processed
What is the difference between short polling and long polling in SQS
Short polling - client sends frequent requests ie., <1sec. SQS responds immediately even if blank.
Long polling - unless poll times out, only responds when a message arrives in queue. It can reduce costs
When would you use long polling instead of short polling in sqs?
When you have high traffic use long polling
When you can afford frequent messages use short Polling
A high resolution video is from ec2 to s3 and waits for s3 to provide data
What should you use to process videos without waiting for a response
SQS
Whst would be the best service for suggestion clothes for users based on what they have in their shopping cart?
Step Function (think of flow chart with branches and loops)
An app that processes customer orders is moving from on-premises to aws.
Order is received, processed, label created and then a confirmation email is sent to customer
What solution creates a maintainable app that completes all steps in this order and doesn’t need self managed cloud infrastructure
Create a lambda function for each task
Use a Step Function to invoke Lambda functions in order
You’re able to take info in from sources such as (AWS services, external SaaS and your own custom apps) and perform actions (filter, manage and direct) them to other systems
These systems listen and take action based on the info
What service is this
Event Bridge
Can you convert scripts to Lambda functions and schedule them with Event Bridge
Yes
Name the states of a Step Function?
CW PPT FM
choice (rule)
wait
pass
parallel
task
fail
map (iterate)
What is short polling?
Short polling is when the client sends frequent requests ie., <1sec. SQS responds immediately even if blank.
What is long polling?
Long polling - unless poll times out, only responds when a message arrives in queue. It can reduce costs
When would you use a lambda function ?
When you have a single stand alone function that responds to an event
When do you use Step Functions?
It’s usually used to help you overcome the issue that lambda has a max 15min execution time
Benefit of SQS is
it builds decoupled apps
