sqs.txt

SQS

- Message queue system. Message retained up to 14 days
- 256K of text. Billed at 64K chunks
- Does NOT guarantee first in, first out. If you need that, use a FIFO SQS queue
- SQS pulls information
- Supports auto scalling
- Visibility timeout window: 12 hours max, default is 30 secs
- "At least once" -- each message is delivered at least once but maybe more. Keep that in mind
- First million SQS hits: free. 0.50 USD per million, per month, after that
- Single request can have from 1 to 10 messages.

* Change visibility timeout with the "ChangeMessageVisibility" method
* Enable LONG POLLING (20 secs) to wait for a message to become available. Raise an event as soon as a message arrives, good for saving money/requests.
* Has SNS integration, SQS subscribes to SNS topic. When SNS msg arrives, distribute msg to suscribed SQS queues. 1 SNS -> N SQS