Integration

Question 1

Step Functions tasks

Answer 1

• Lambda tasks
• Activity tasks: HTTP worker (EC2, mobile device, on premise)
• Service task: connect to supported aws services
• Wait task

Question 2

Step Functions Standard vs Express

Answer 2

• Standard: exactly-once execution maximum 1 year duration. Priced per state transition. Executions can be listed and described
• Express: at-least-once execution maximum 5 minutes duration. Higher start and transition rate. Priced by number of executions.

Question 3

Step Functions

Synchronous and Asynchronous Express Workflows

Answer 3

Asynchronous Express Workflows return confirmation that the workflow was started, but don’t wait for the workflow to complete
Synchronous Express Workflows start a workflow, wait until it completes, and then return the result.

Question 4

SQS

Answer 4

• Used to decouple services
• Max 256KB for message size
• Could be used as a write buffer for DynamoDB
• Supports FIFO

Question 5

SQS Dead Letter Queue

Answer 5

After the MaximumReceives threshold is exceeded the message goes into a DLQ. The queue type should match the original queue.
It is useful for debugging.

Question 6

SQS Idempotency

Answer 6

Messages can be processed twice by consumer. Idempotency must be implemented at the consumer level.

Question 7

Amazon MQ

Answer 7

Managed Message broker for RabbitMQ and ActiveMQ, doesn’t scale as much as SQS.

Use it with traditional protocols when migrating to the cloud, insted of re-engineering the application.

Question 8

S3 events to multiple queues

Answer 8

Use the fan-out pattern with SNS+SQS to send the same S3 event type and prefix.

Question 9

Integration between SNS and S3

Answer 9

From SNS send to Kinesis Data Firehose and from there to S3.

https://medium.com/@twcardenas/streaming-data-to-s3-from-sns-using-firehose-1f27a8c23a0c

Question 10

SNS Message Filtering

Answer 10

Policy to filter messages sent to SNS topics subscriptions. If a subscription doesn’t have a filter policy, it receives every message.

Question 11

SNS Message Delivery Retries

Answer 11

In case of server side error a delivery policy is applied
* Immediate retry phase (no delay): 3 times for AWS managed endpoints
* Pre backoff phase
* Backoff phase
* Post backoff phase

Question 12

SNS Custom Delivery Policies

Answer 12

Only HTTP/S supports custom policies.
1. Healthy Retry Policy
2. Sickly Retry Policy
3. Throttle Policy

Question 13

SNS - Dead Letter Queue

Answer 13

After exhausting the delivery policy, messages are sent to a DLQ.

DLQ are attached to a subscription.

Question 14

API Gateway HTTP endpoint AWS service integrations

Answer 14

1. EventBridge
2. SQS
3. AppConfig
4. Kinesis
5. Step Functions

Question 15

Amazon Pinpoint

Answer 15

Send push notifications, in-app notifications, emails, text messages, voice messages, and messages over custom channels.