Creating a rule that runs on a schedule in Amazon EventBridge

A rule can run in response to an event, or at certain time intervals. For example, to periodically run an AWS Lambda function, you can create a rule to 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.

In EventBridge, you can create two types of scheduled rules:

• Rules that run at a regular rate

  EventBridge runs these rules at regular intervals; for example, every 20 minutes.

  To specify the rate for a scheduled rule, you define a rate expression.

• Rules that run at specific times

  EventBridge runs these rules at specific times and dates; for example, 8:00 a.m. PST on the first Monday of every month.

  To specify the time and dates a scheduled rule runs, you define a cron expression.

Rate expressions are simpler to define, while cron expressions offer detailed schedule control. For example, with a cron expression, you can define a rule that runs at a specified time on a certain day of each week or month. In contrast, rate expressions run a rule at a regular rate, such as once every hour or once every day.

All scheduled events use UTC+0 time zone, and the minimum precision for a schedule is one minute.

Note

EventBridge doesn't provide second-level precision in schedule expressions. The finest resolution using a cron expression is one minute. Due to the distributed nature of EventBridge and the target services, there can be a delay of several seconds between the time the scheduled rule is triggered and the time the target service runs the target resource.

The following video gives an overview of scheduling tasks:

Create a rule that runs on a schedule

The following steps walk you through how to create an EventBridge rule that runs on a regular schedule.

Note

You can only create scheduled rules using the default event bus.

Steps

• Define the rule
• Define the schedule
• Select targets
• Configure tags and review rule

Define the rule

First, enter a name and description for your rule to identify it.

To define the rule detail

1. Open the Amazon EventBridge console at https://console.aws.amazon.com/events/.

2. In the navigation pane, choose Rules.

3. Choose Create rule.

4. Enter a Name and, optionally, a Description for the rule.

   A rule can't have the same name as another rule in the same AWS Region and on the same event bus.

5. For Event bus, choose the default event bus. You can only create scheduled rules using the default event bus.

6. To have the rule take effect as soon as you create it, make sure the Enable the rule on the selected event bus option is enabled.

7. For Rule type, choose Schedule.

   At this point, you can choose to continue with creating a rule that runs on a schedule, or use Amazon EventBridge Scheduler.

8. Choose how you want to continue:

   • Use EventBridge Scheduler to create your schedule

     Note

     EventBridge Scheduler is a serverless scheduler that allows you to create, run, and manage tasks from one central, managed service. It provides one-time and recurring scheduling functionality independent of event buses and rules. EventBridge Scheduler is highly customizable, and offers improved scalability over EventBridge scheduled rules, with a wider set of target API operations and AWS services.

     We recommend that you use EventBridge Scheduler to invoke targets on a schedule. For more information, see What is Amazon EventBridge Scheduler? in the Amazon EventBridge Scheduler User Guide.

     1. Select Continue in EventBridge Scheduler

        EventBridge opens the EventBridge Scheduler console to the Create schedule page.

     2. Create the schedule in the EventBridge Scheduler console.

   • Continue using EventBridge to create a scheduled rule for the default event bus

     1. Select Continue to create rule.

Define the schedule

Next, define the schedule pattern.

To define the schedule pattern

1. For Schedule pattern, choose whether you want the schedule to run at a specific time, or at a regular rate:

   Specific time

   1. Choose A fine-grained schedule that runs at a specific time, such as 8:00 a.m. PST on the first Monday of every month.

   2. For Cron expression, specify fields to define the cron expresssion that EventBridge should use to determine when to execute this scheduled rule.

      Once you have specified all fields, EventBridge displays the next ten dates when EventBridge will execute this scheduled rule. You can choose whether to display those dates in UTC or Local time zone.

      For more information on constructing a cron expression, see Cron expressions.

   Regular rate

   1. Choose A schedule that runs at a regular rate, such as every 10 minutes.

   2. For Rate expression, specify the Value and Unit fields to define the rate at which EventBridge should execute this scheduled rule.

      For more information on constructing a rate expression, see Rate expressions.

2. Choose Next.

Select targets

Choose one or more targets to receive events that match the specified pattern. Targets can include an EventBridge event bus, EventBridge API destinations, including SaaS partners such as Salesforce, or another AWS service.

To select targets

1. For Target type, choose one of the following target types:

   Event bus

   To select an EventBridge event bus, select EventBridge event bus, then do the following:

   • To use an event bus in the same AWS Region as this rule:

     1. Select Event bus in the same account and Region.

     2. For Event bus for target, choose the dropdown box and enter the name of the event bus. You can also select the event bus from the dropdown list.

        For more information, see Sending events between event buses in the same account and Region in Amazon EventBridge.

   • To use an event bus in a different AWS Region or account as this rule:

     1. Select Event bus in a different account or Region.

     2. For Event bus as target, enter the ARN of the event bus you want to use.

        For more information, see:

        • Sending and receiving events between AWS accounts in Amazon EventBridge

        • Sending and receiving events between AWS Regions in Amazon EventBridge

   API destination

   To use an EventBridge API destination, select EventBridge API destination, then do one of the following:

   • To use an existing API destination, select Use an existing API destination. Then select an API destination from the dropdown list.

   • To create a new API destination, select Create a new API destination. Then, provide the following details for the destination:

     • Name – Enter a name for the destination.

       Names must be unique within your AWS account. Names can have up to 64 characters. Valid characters are A-Z, a-z, 0-9, and . _ - (hyphen).

     • (Optional) Description – Enter a description for the destination.

       Descriptions can have up to 512 characters.

     • API destination endpoint – The URL endpoint for the target.

       The endpoint URL must start with https. You can include the * as a path parameter wildcard. You can set path parameters from the target's HttpParameters attribute.

     • HTTP method – Select the HTTP method used when you invoke the endpoint.

     • (Optional) Invocation rate limit per second – Enter the maximum number of invocations accepted for each second for this destination.

       This value must be greater than zero. By default, this value is set to 300.

     • Connection – Choose to use a new or existing connection:

       • To use an existing connection, select Use an existing connection and select the connection from the dropdown list.

       • To create a new connection for this destination select Create a new connection, then define the connection's Name, Destination type, and Authorization type. You can also add an optional Description for this connection.

   For more information, see API destinations as targets in Amazon EventBridge.

   AWS service

   To use an AWS service, select AWS service, then do the following:

   1. For Select a target, select an AWS service to use as the target. Provide the information requested for the service you select.

      Note

      The fields displayed vary depending on the service selected. For more information about available targets, see Event bus targets available in the EventBridge console.

2. For many target types, EventBridge needs permissions to send events to the target. In these cases, EventBridge can create the IAM role needed for your rule to run.

   For Execution role, do one of the following:

   • To create a new execution role for this rule:

     1. Select Create a new role for this specific resource.

     2. Either enter a name for this execution role, or use the name generated by EventBridge.

   • To use an existing execution role for this rule:

     1. Select Use existing role.

     2. Enter or select the name of the execution role to use from the dropdown list.

3. (Optional) For Additional settings, specify any of the optional settings available for your target type:

   Event bus

   (Optional) For Dead-letter queue, choose whether to use a standard Amazon SQS queue as a dead-letter queue. EventBridge sends events that match this rule to the dead-letter queue if they are not successfully delivered to the target. Do one of the following:

   • Choose None to not use a dead-letter queue.

   • Choose Select an Amazon SQS queue in the current AWS account to use as the dead-letter queue and then select the queue to use from the drop-down list.

   • Choose Select an Amazon SQS queue in an other AWS account as a dead-letter queue and then enter the ARN of the queue to use. You must attach a resource-based policy to the queue that grants EventBridge permission to send messages to it.

     For more information, see Granting permissions to the dead-letter queue.

   API destination

   1. (Optional) For Configure target input, choose how you want to customize the text sent to the target for matching events. Choose one of the following:

      • Matched events – EventBridge sends the entire original source event to the target. This is the default.

      • Part of the matched events – EventBridge only sends the specified portion of the original source event to the target.

        Under Specify the part of the matched event, specify a JSON path that defines the part of the event you want EventBridge to send to the target.

      • Constant (JSON text) – EventBridge sends only the specified JSON text to the target. No part of the original source event is sent.

        Under Specify the constant in JSON, specify the JSON text that you want EventBridge to send to the target instead of the event.

      • Input transformer – Configure an input transformer to customize the text you want EventBridge send to the target. For more information, see Amazon EventBridge input transformation.

        1. Select Configure input transformer.

        2. Configure the input transformer following the steps in Configuring an input transformer when creating a rule in EventBridge.

   2. (Optional) Under Retry policy, specify how EventBridge should retry sending an event to a target after an error occurs.

      • Maximum age of event – Enter the maximum amount of time (in hours, minutes, and seconds) for EventBridge to retain unprocessed events. The default is 24 hours.

      • Retry attempts – Enter the maximum number of times EventBridge should retry sending an event to the target after an error occurs. The default is 185 times.

   3. (Optional) For Dead-letter queue, choose whether to use a standard Amazon SQS queue as a dead-letter queue. EventBridge sends events that match this rule to the dead-letter queue if they are not successfully delivered to the target. Do one of the following:

      • Choose None to not use a dead-letter queue.

      • Choose Select an Amazon SQS queue in the current AWS account to use as the dead-letter queue and then select the queue to use from the drop-down list.

      • Choose Select an Amazon SQS queue in an other AWS account as a dead-letter queue and then enter the ARN of the queue to use. You must attach a resource-based policy to the queue that grants EventBridge permission to send messages to it.

        For more information, see Granting permissions to the dead-letter queue.

   AWS service

   Note that EventBridge may not display all of the following fields for a given AWS service.

   1. (Optional) For Configure target input, choose how you want to customize the text sent to the target for matching events. Choose one of the following:

      • Matched events – EventBridge sends the entire original source event to the target. This is the default.

      • Part of the matched events – EventBridge only sends the specified portion of the original source event to the target.

        Under Specify the part of the matched event, specify a JSON path that defines the part of the event you want EventBridge to send to the target.

      • Constant (JSON text) – EventBridge sends only the specified JSON text to the target. No part of the original source event is sent.

        Under Specify the constant in JSON, specify the JSON text that you want EventBridge to send to the target instead of the event.

      • Input transformer – Configure an input transformer to customize the text you want EventBridge send to the target. For more information, see Amazon EventBridge input transformation.

        1. Select Configure input transformer.

        2. Configure the input transformer following the steps in Configuring an input transformer when creating a rule in EventBridge.

   2. (Optional) Under Retry policy, specify how EventBridge should retry sending an event to a target after an error occurs.

      • Maximum age of event – Enter the maximum amount of time (in hours, minutes, and seconds) for EventBridge to retain unprocessed events. The default is 24 hours.

      • Retry attempts – Enter the maximum number of times EventBridge should retry sending an event to the target after an error occurs. The default is 185 times.

   3. (Optional) For Dead-letter queue, choose whether to use a standard Amazon SQS queue as a dead-letter queue. EventBridge sends events that match this rule to the dead-letter queue if they are not successfully delivered to the target. Do one of the following:

      • Choose None to not use a dead-letter queue.

      • Choose Select an Amazon SQS queue in the current AWS account to use as the dead-letter queue and then select the queue to use from the drop-down list.

      • Choose Select an Amazon SQS queue in an other AWS account as a dead-letter queue and then enter the ARN of the queue to use. You must attach a resource-based policy to the queue that grants EventBridge permission to send messages to it.

        For more information, see Granting permissions to the dead-letter queue.

4. (Optional) Choose Add another target to add another target for this rule.

5. Choose Next.

Configure tags and review rule

Finally, enter any desired tags for the rule, then review and create the rule.

To configure tags, and review and create the rule

1. (Optional) Enter one or more tags for the rule. For more information, see Tagging resources in Amazon EventBridge.

2. Choose Next.

3. Review the details for the new rule. To make changes to any section, choose the Edit button next to that section.

   When satisfied with the rule details, choose Create rule.