Amazon Simple Notification Service (SNS) | Reliability Flashcards
What else is Amazon SNS compliant with?
Reliability
Amazon Simple Notification Service (SNS) | Application Integration
Please see AWS Services in Scope by Compliance Program for the latest information about SNS and other AWS services.
How reliable is my data once published to Amazon SNS?
Reliability
Amazon Simple Notification Service (SNS) | Application Integration
Amazon SNS stores all topic and message information within Amazon’s proven network infrastructure and datacenters. At least three copies of the data are stored across multiple availability zones, which means that no single computer or network failure renders Amazon SNS inaccessible.
Will a notification contain more than one message?
Reliability
Amazon Simple Notification Service (SNS) | Application Integration
No, all notification messages will contain a single published message.
How many times will a subscriber receive each message?
Reliability
Amazon Simple Notification Service (SNS) | Application Integration
Although most of the time each message will be delivered to your application exactly once, the distributed nature of Amazon SNS and transient network conditions could result in occasional, duplicate messages at the subscriber end. Developers should design their applications such that processing a message more than once does not create any errors or inconsistencies.
Will messages be delivered to me in the exact order they were published?
Reliability
Amazon Simple Notification Service (SNS) | Application Integration
The Amazon SNS service will attempt to deliver messages from the publisher in the order they were published into the topic. However, network issues could potentially result in out-of-order messages at the subscriber end.
Can a message be deleted after being published?
Reliability
Amazon Simple Notification Service (SNS) | Application Integration
No, once a message has been successfully published to a topic, it cannot be recalled.
Does Amazon SNS guarantee that messages are delivered to the subscribed endpoint?
Reliability
Amazon Simple Notification Service (SNS) | Application Integration
When a message is published to a topic, Amazon SNS will attempt to deliver notifications to all subscribers registered for that topic. Due to potential Internet issues or Email delivery restrictions, sometimes the notification may not successfully reach an HTTP or Email end-point. In the case of HTTP, an SNS Delivery Policy can be used to control the retry pattern (linear, geometric, exponential backoff), maximum and minimum retry delays, and other parameters. If it is critical that all published messages be successfully processed, developers should have notifications delivered to an SQS queue (in addition to notifications over other transports).
