Why Choose Amazon Kinesis Over SNS-SQS? Understanding AWS Streaming Solutions

When designing a data pipeline, you’re often faced with the choice between Amazon Kinesis and the SNS-SQS combination. Understanding the fundamental differences between these options is critical to make an informed decision. Here’s what you need to know to make that choice effectively.

Use Case Considerations

You mentioned needing a buffer to handle a data stream that cannot be consumed at the same rate it is produced. Both Amazon Kinesis and an SNS-SQS setup can be employed in such scenarios, but your decision should hinge on specific use case requirements.

Amazon Kinesis

Kinesis shines in scenarios where message order and data reprocessing are paramount. Its strengths include:

1. Ordered Processing: With Kinesis, you get a built-in guarantee that your data will be processed in the order it was received. This makes it an excellent fit for real-time analytics and applications that depend on order-dependent data streams.

2. Multiple Consumers: Kinesis allows multiple consumer applications to consume data concurrently. This is a default feature and facilitates complex data processing architectures without extra configuration.

3. Data Reprocessing: Kinesis retains data by default for up to seven days, which allows you to reprocess or backfill data if needed. This window should be evaluated against your application’s requirements for replayability.

AWS documentation: For more detailed information on Kinesis and its features, consider visiting the Amazon Kinesis documentation.

SNS-SQS

The SNS-SQS combination provides considerable simplicity and flexibility:

1. Fan-out Pattern: SNS can effectively distribute messages to multiple SQS queues, allowing various consumers to process the same data. This setup mirrors the multiple consumers feature in Kinesis but with additional simplicity in setup and handling.

2. Flexible Retention: SQS allows messages to be retained for up to 14 days. If your use case requires longer retention, this can give you more leeway compared to Kinesis’s 7-day limit.

3. FIFO Support: While traditionally SNS-SQS setups didn’t support ordered processing, AWS has introduced FIFO (First-In-First-Out) capabilities for both SNS topics and SQS queues. However, enabling FIFO may introduce constraints, such as limiting the number of consumers, which is something to consider.

SNS and SQS can be combined effectively when using SNS to fan out messages across multiple SQS queues. Each queue can handle messages for different applications or services, providing flexibility.

Decision Criteria

• Message Order: If maintaining message order is crucial, and your consumers need to read records with guaranteed ordering, Kinesis is typically the better choice.
• Replayability and Retention: Consider Kinesis if a 7-day retention period is adequate. Opt for SNS-SQS if you require up to 14 days or prefer complete control over message flow.
• Integration Complexity and Cost: Evaluate the added complexity SNS-SQS might introduce in managing message fan-out and retention compared to Kinesis. Pricing models and expected traffic volume should also influence your decision.

Ultimately, the right choice depends on the specific requirements of your data stream, the need for ordered processing, and the scale at which you plan to operate.