Once a day, BDS checks to see if the BDS Bucket has gone from “empty” to “non-empty”. If so, BDS sends a notification to an SNS topic maintained by the end user. This notification warns that events have been written into the Bucket and therefore that there’s a problem writing to the Kinesis stream.
Since BDS only makes this check once a day, there may be a considerable lag between when events start getting written to the Bucket and when the SNS topic receives the notification.
Notifications are only sent when the Bucket is empty one day and non-empty the next. If the Bucket is non-empty, and then you empty it but more events are put into the Bucket before the next check, you will not receive a notification since the Bucket will be non-empty on consecutive checks.
Bucket checks are performed at arbitrary times during the day. Do not assume that consecutive checks are exactly 24 hours apart.
To receive notifications sent to the SNS topic, you must subscribe to the topic. You may set up subscriptions to activate lambda software, to send messages to an SQS queue, to text or email notifications to one or more people, or to take some other action. A comprehensive approach is to subscribe to the topic with an SQS queue, then have SQS trigger an appropriate lambda as well as sending text messages or email to your support personnel.
Configuring the SNS Topic¶
The easiest way to configure the BDS SNS topic is to use the AWS console. Do this after you have configured the Bucket.
AWS provides a Setting Up SNS Topics tutorial that walks you through the process of creating an SNS topic and subscribing to it. You can use this tutorial as a model for creating an SNS topic that BDS can use, and for having people subscribe to the topic.
You can set up a subscription to send SMS text messages to one or more people, or to a mobile app. You can also set up a subscription to send email to one or more people.
When you have successfully created the topic and any subscriptions you’d like, you must give BDS permission to write notifications to the topic. When you enroll for BDS, you will be given the AWS account to which you must grant this permission.