Event Processing Patterns

Question 1

What does DLQ stand for?

Answer 1

Dead-Letter Queue

Question 2

What are the three AWS services that use DLQs?

Answer 2

• SNS - if a topic fails to deliver
• SQS - if maxRecieveCount is exceeded
• Lambda - if an asynchronous invocation fails after the set number of retries

Question 3

What is the Fanout Pattern?

Answer 3

When a publisher uses an SNS topic to send the same message to many places (the SNS topic duplicates the message and sends it to each of those places)

Question 4

What types of events trigger S3 event notifications?

Answer 4

• Object Created
• Object Removed
• Object Restored (from Glacier)
• RRS Object Lost
• Replication
  
  • ​Replication Failed
  • Replication Exceeds 15 mins
  • Object no longer tracked by replication

Question 5

What AWS Resources are capable of consuming S3 Event Notifications?

Answer 5

• SQS
• SNS
• Lambda