Reducing messaging costs with Basic Ingest - AWS IoT Core
Using Basic Ingest

Reducing messaging costs with Basic Ingest

You can use Basic Ingest, to securely send device data to the AWS services supported by AWS IoT rule actions, without incurring messaging costs. Basic Ingest optimizes data flow by removing the publish/subscribe message broker from the ingestion path.

Basic Ingest can send messages from your devices or applications. The messages have topic names that start with $aws/rules/rule_name for their first three levels, where rule_name is the name of the AWS IoT rule that you want to invoke.

You can use an existing rule with Basic Ingest by adding the Basic Ingest prefix ($aws/rules/rule_name) to the message topic that you'd use to invoke the rule. For example, if you have a rule named BuildingManager that's invoked by messages with topics like Buildings/Building5/Floor2/Room201/Lights ("sql": "SELECT * FROM 'Buildings/#'"), you can invoke the same rule with Basic Ingest by sending a message with topic $aws/rules/BuildingManager/Buildings/Building5/Floor2/Room201/Lights.

Note

  • Your devices and rules can't subscribe to Basic Ingest reserved topics. For example, the AWS IoT Device Defender metric num-messages-received metrics is not emitted as it doesn't support subscribing to topics. For more information, see Reserved topics.

  • If you need a publish/subscribe broker to distribute messages to multiple subscribers (for example, to deliver messages to other devices and the rules engine), you should continue to use the AWS IoT message broker to handle the message distribution. However, make sure that you publish your messages on topics other than Basic Ingest topics.

Using Basic Ingest

Before you use Basic Ingest, verify that your device or application is using a policy that has publish permissions on $aws/rules/*. Or, you can specify permission for individual rules with $aws/rules/rule_name/* in the policy. Otherwise, your devices and applications can continue to use their existing connections with AWS IoT Core.

When the message reaches the rules engine, there's no difference in implementation or error handling between rules invoked from Basic Ingest and those invoked through message broker subscriptions.

You can create rules for use with Basic Ingest. Keep in mind the following:

  • The initial prefix of a Basic Ingest topic ($aws/rules/rule_name) isn't available to the topic(Decimal) function.

  • If you define a rule that's invoked only with Basic Ingest, the FROM clause is optional in the sql field of the rule definition. It's still required if the rule is also invoked by other messages that must be sent through the message broker (for example, because those other messages must be distributed to multiple subscribers). For more information, see AWS IoT SQL reference.

  • The first three levels of the Basic Ingest topic ($aws/rules/rule_name) aren't counted toward the 8-segment length limit or toward the 256-total character limit for a topic. Otherwise, the same restrictions apply as documented in AWS IoT Limits.

  • If a message is received with a Basic Ingest topic that specifies an inactive rule or a rule that doesn't exist, an error log is created in an Amazon CloudWatch log to help you with debugging. For more information, see Rules engine log entries. A RuleNotFound metric is indicated and you can create alarms on this metric. For more information, see Rule Metrics in Rule metrics.

  • You can still publish with QoS 1 on Basic Ingest topics. You receive a PUBACK after the message is successfully delivered to the rules engine. Receiving a PUBACK doesn't mean that your rule actions were completed successfully. You can configure an error action to handle errors when an action is run. For more information, see Error handling (error action).