SQS Flashcards
What is Amazon SQS?
Amazon SQS (Simple Queue Service) is a fully managed message queuing service that enables you to decouple and scale microservices, distributed systems, and serverless applications. It eliminates the complexity and overhead associated with managing and operating message-oriented middleware.
How does SQS support the decoupling of applications?
SQS allows components of a cloud application to communicate asynchronously by storing messages in a queue. Messages are stored until the receiving component can process them, enabling one component to operate independently of other components.
What are the types of queues offered by SQS?
SQS offers two types of queues: Standard queues, which offer maximum throughput, best-effort ordering, and at-least-once delivery; and FIFO queues, which are designed to guarantee that messages are processed exactly once, in the exact order that they are sent.
How does SQS ensure message processing?
SQS ensures message processing by retaining messages in queues until they are retrieved and processed by receiving components. SQS supports message visibility timeout to prevent other consumers from receiving the message while it’s being processed.
What is a visibility timeout in SQS?
The visibility timeout is the period of time during which SQS prevents other consuming components from receiving and processing a message that has already been retrieved by another component.
How can you secure SQS queues?
You can secure SQS queues using AWS IAM (Identity and Access Management) to control who can send messages to and receive messages from an SQS queue. Additionally, you can encrypt messages in transit using SSL and at rest using server-side encryption (SSE) with keys managed by AWS Key Management Service (KMS).
What is the maximum message size for SQS?
The maximum message size for SQS messages is 256 KB for both Standard and FIFO queues.
How is SQS priced?
SQS is priced based on the number of API calls made to the service. Sending, receiving, and deleting messages are billed in increments of 1 million requests, and there’s no charge for the first 1 million requests per month. FIFO queues have an additional cost for messages transferred out of an AWS region.
What are dead-letter queues in SQS?
Dead-letter queues are used to hold messages that can’t be processed successfully by your application. These queues enable you to isolate problematic messages to diagnose processing failures and mitigate issues without losing the message data.
How does SQS integrate with other AWS services?
SQS integrates with other AWS services like AWS Lambda, Amazon SNS, and Amazon EC2, enabling you to build flexible, scalable cloud applications. For example, Lambda functions can be triggered by messages in an SQS queue to process data.
