Amazon SQS Standard Queues Overview¶

Amazon SQS - Standard Queue¶

• Oldest offering (over 10 years old)

• Fully managed service, used to decouple applications

• Attributes:

  • Unlimited throughput, unlimited number of messages in queue
  • Default retention of messages: 4 days, maximum 14 days
  • Low latency (<10 ms on publish and receive)
  • Limitation of 256KB per message sent
• Can have duplicate messages (at least once delivery, occasionally)
• Can have out of order messages (best effort ordering)

Producing Messages¶

• Produced to SQS using the SDK (SendMessage API)
• The message is persisted in SQS until a consumer deletes it
• Message retention: 4 days, maximum 14 days

• Example: send an order to be processed

  • Order ID
  • Customer ID
  • Any attributes you want

• SQS standard: unlimited throughput

• Message up to 256KB

Consuming Messages¶

• Consumers (running on EC2 instances, servers or AWS Lambda)
• Poll SQS for messages (receive up to 10 messages at a time)
• Process the messages (example: insert the message into an RDS database)
• Delete the messages using the DeleteMessage API

Multiple EC2 Instances Consumers¶

• Consumers receive and process messages in parallel
• At least once delivery
• Best-effort message ordering
• Consumers delete messages after processing them
• We can scale consumers horizontally to improve throughput of processing

SQS with Auto Scaling Group¶

Declouple between application tiers¶

Security¶

• Encryption
  • In-flight encryption using HTTPS API
  • At-rest encryption using KMS Keys
  • Client-side encryption if the client wants to perform encryption/decryption itself
• Access Controls: IAM policies to regulate access to the SQS API
• SQS Access Policies (similar to S3 bucket policies)
  • Useful for cross-account access to SQS queues
  • Useful for allowing other services (SNS, S3...) to write to an SQS queue