Amazon EventBridge was announced at the AWS New York Summit in 2019. It’s a serverless event bus service that uses the Amazon CloudWatch Events API, but also includes more functionality, like the ability to ingest events from SaaS apps. The EventBridge service uses the CloudWatch Events API and it is fully backward compatible, so you don’t need to make any changes to your existing CloudFormation templates or API calls. Event-based architectures can make it easier to decouple your application services and make your systems more extensible.

Events are emitted from services throughout AWS, and you can create custom events from your own applications. The popularity of event-based compute is why CloudWatch Events grew to process trillions of events every month. See this video for an overview of the features of the EventBridge service.

EventBridge is designed to extend the event model beyond AWS, bringing data from software as a service (SaaS) providers into your AWS environment. This means you can consume events from popular providers such as Zendesk, PagerDuty, and Auth0. You can use these in your applications with the same ease as any AWS-generated event.

This blog post explains the differences between the CloudWatch Events and EventBridge, and the benefits of upgrading. I also provide additional resources to help you gain the benefits of using the newer EventBridge service.

Integrated SaaS providers in EventBridge

Fetching data from third-party providers has typically relied on processes such as polling, or building custom webhooks where these are supported. Polling is compute-intensive and often wasteful, since many requests return no new data. Additionally, there is a lag between new data becoming available and your system receiving the information.

While webhooks offers improvements over polling and may approximate a real-time connection, these requests travel over the public internet. This means you must secure the webhook endpoint, and use a security mechanism between the two services. You must also scale up if the SaaS provider sends large numbers of messages.

EventBridge enables SaaS providers to publish data on an event bus within their AWS environment. These events are then routed to your AWS account, and appear on your partner event bus. All of this happens on the private AWS network, away from the public internet. The service manages scaling, security, and integration for you.

Configuring EventBridge in your SaaS provider account is easy. To learn how to set up the integration, see these videos for a full walkthrough:

A full list of EventBridge SaaS integrations is available on the EventBridge website. Additionally, if you want to integrate your own SaaS software with EventBridge, read more in the onboarding guide.

Custom event buses and enhanced rules

CloudWatch Events provides a default event bus that exists in every AWS account. All AWS events are routed via the default bus. You can also choose to publish your custom events to the default bus.

EventBridge introduces custom event buses you can use exclusively for your own workloads. These can be useful for controlling access to events to a limited set of AWS accounts or custom applications. Custom event buses are free to set up. Watch this video to see how to set up a custom event bus.

You can also use powerful advanced rules for routing events. With content-based filtering, you can use comparison operators to identify and filter values in events. This allows you to use EventBridge to handle more processing on behalf of your application, reducing the load on downstream services. See this blog post to learn more about using content-filtering to build advanced rules.

Schema registry

One of the traditional challenges of working with event-based architectures is the administration of managing event structures. With different applications, services and microservices publishing events, it can be hard to standardize event formats. These formats, or schemas, may also change when developers introduce new versions of their services.

The EventBridge Schema Registry allows you to automate the discovery and creation of schemas. You can find schemas for AWS services, integrated SaaS providers, and your own custom events. EventBridge infers the schemas and stores these in a registry. You can then download custom code bindings for popular type-safe programming languages. This accelerates the development process, making it easy to construct objects based on events.

Watch this video to see how to use the EventBridge Schema Registry, and get started with your own applications.

Migration and compatibility

Comparing the EventBridge console and CloudWatch Events console, EventBridge has a new design that makes it easier to build and manage rules and event buses. If you are new to using events within AWS, it’s recommended that you start with the EventBridge console.

The EventBridge service uses the CloudWatch Events API and it is fully backward compatible. Any rules you have configured in CloudWatch Events continue to work in EventBridge. You can access the default event bus and any configurations you created in CloudWatch Events from EventBridge immediately. If you’re a current CloudWatch Events customer, you can upgrade to EventBridge by simply opening the EventBridge console.

AWS continues to build new functionality to enhance the capabilities of event-based architectures. These features are only released via EventBridge, so it’s recommended that you upgrade to ensure you can take advantage of these new capabilities.

Additional EventBridge resources for serverless developers

Event-based architectures can help serverless developers create dynamic, decoupled applications. Here are additional resources with sample code repos to help you get started:

Conclusion

EventBridge is the evolution of the CloudWatch Events service. It brings new features, including the ability to integrate data from popular SaaS providers as events within AWS.

In this post, I discuss the new ability to create custom event buses, and how you can develop advanced rules for sophisticated event routing. I also discuss the new EventBridge Schema Registry, which automates event schema discovery, and downloading code bindings directly into your IDE.

New event-based features are now released in EventBridge. By migrating from CloudWatch Events, you can take advantage of new capabilities as they are released.

To learn more about using EventBridge for your AWS workloads, visit the EventBridge Learning Path, which includes a range of learning resources.