Rules in Amazon EventBridge
You specify what EventBridge does with the events delivered to each event bus. To do this, you create rules. A rule specifies which events to send to which targets for processing. A single rule can send an event to multiple targets, which then run in parallel.
You can create two types of rules: rules that match on event data as events are delivered, and rules that run on a defined schedule. In addition, certain AWS services may create and manage rules in your account as well.
Rules that match on event data
You can create rules that match against incoming events based on event data criteria (called an event pattern). An event pattern defines the event structure and the fields that a rule matches. If an event matches the criteria defined in the event pattern, EventBridge sends it to the target(s) you specify.
For more information, see Creating rules that react to events in Amazon EventBridge.
Rules that run on a schedule
Note
While you can create rules that run on a schedule, EventBridge now offers a more flexible and powerful way to create, run, and manage scheduled tasks centrally: EventBridge Scheduler. With EventBridge Scheduler, you can create schedules using cron and rate expressions for recurring patterns, or configure one-time invocations. You can set up flexible time windows for delivery, define retry limits, and set the maximum retention time for failed API invocations.
Scheduler is highly customizable, and offers improved scalability over scheduled rules, with a wider set of target API operations and AWS services. We recommend that you use Scheduler to invoke targets on a schedule.
For more information, see Create a schedule.
You can also create rules that sends events to the specified targets at specified intervals. For example, to periodically run an Lambda function, you can create a rule to run on a schedule.
For more information, see Creating a rule that runs on a schedule in Amazon EventBridge.
Rules managed by AWS services
In addition to the rules you create, AWS services can create and manage EventBridge rules in your AWS account that are needed for certain functions in those services. These are called managed rules.
When a service creates a managed rule, it can also create an IAM policy that grants permission to that service to create the rule. IAM policies created this way are scoped narrowly with resource-level permissions to allow the creation of only the necessary rules.
You can delete managed rules by using the Force delete option, but you should only delete them if you're sure that the other service no longer needs the rule. Otherwise, deleting a managed rule causes the features that rely on it to stop working.
The following video covers the basics of rules:
