Amazon SQS

1. What is Amazon SQS and queue types

   Message queuing, producers and consumers, and decoupling components.

2. Standard queues

   At-least-once delivery, best-effort ordering and nearly unlimited throughput.

3. FIFO queues

   Exactly-once processing, message group IDs and deduplication IDs.

4. Visibility timeout

   How in-flight messages are hidden from other consumers and when they reappear.

5. Short and long polling

   Receive wait time, empty receives and reducing cost with long polling.

6. Dead-letter queues

   Redrive policies, maxReceiveCount and isolating unprocessable messages.

7. Delay queues

   Postponing delivery of new messages with delay seconds.

8. Features and capabilities

   Message attributes, retention, batching, large payloads and encryption.

9. Access policies and security

   Queue policies, IAM, server-side encryption and VPC endpoints.

10. Best practices

    Batching, polling, idempotent consumers and cost recommendations.

11. Quotas

    Message size, retention, in-flight messages and throughput limits.

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