There are two types of queues:

• Standard
  • at least once delivery
  • no order processing
• FIFO (First-in-first-out)
  • order processing
  • can be differentiated with message group id too.
  • two de-depulication methods
    • hashing message body (or)
    • setting de-dpulication id
• Maximum 14 days for data retention

Visibility timeout - if a message is not processed within the duration, it is sent back to queue for other consumers

Delay time - the amount of time before the client is able to see the message

Dead letter queue - When a message exceeds maximum number of retries, it can go to DLQ for debugging

SNS + SQS = Fanout pattern

• Producers sent messages into SNS topic and these messages are sent out all to SQS queues that are subscribes of particular SNS topic.

Kinesis

Kinesis data streams

• one consumer per shard
• Publishers can send messages via Kinesis Producer Library, Cloudwatch, or IOT devices
• 1mb or 1000msg/sec for write throughput