Amazon EventBridge is a serverless event bus service that makes it simple to link your apps to data from several sources. EventBridge streams real-time data from your applications, Software-as-a-Service (SaaS) apps, and AWS services and directs it to destinations such as AWS Lambda. You may create routing rules to define where your data should be sent to create application architectures that respond in real-time to all of your data sources.
Let us start with An Introduction to Amazon EventBridge: Learn to Build Event-Driven Applications!
What is AWS EventBridge?
Amazon EventBridge is a serverless event bus service provided by Amazon Web Services (AWS). It enables you to send and receive events between applications, services, and AWS resources. With EventBridge, you can create event-driven architectures that respond to real-time events from your own applications, SaaS applications, and AWS services. EventBridge is fully managed and can automatically route events to AWS Lambda functions, Amazon SNS topics, Amazon SQS queues, and other AWS services.
EventBridge extends this capability outside of the AWS environment, allowing you to connect your own (old) applications, SaaS (Software-as-a-Service), and AWS Services. It can feed real-time data from a variety of event sources such as PagerDuty and Symantec and route it to a variety of destinations (AWS services such as SQS, Lambda, and others). EventBridge debuted with support for ten SaaS application partners, over 90 AWS services as event sources, and 17 AWS services as targets.
What sets EventBridge apart from other AWS services?
EventBridge is an AWS service that provides a serverless event bus that allows developers to automate and respond to events generated by AWS services, custom applications, and SaaS applications. EventBridge is unique in that it provides a single, unified way to connect events across different AWS services and third-party applications, making it easier to build event-driven applications.
Additionally, EventBridge uses a rule-based system to route events to their intended targets, providing a scalable and flexible way to process events without having to manage infrastructure. This makes EventBridge an effective tool for building event-driven architectures, enabling you to focus on writing code that responds to events, rather than managing infrastructure.
Let’s have a look at the various event routing choices available on AWS and see how they compare to EventBridge. For event routing, there are four primary AWS-native options:
- CloudWatch Events
- SNS
- EventBridge
- Kinesis
Let us learn about the differences between these.
CloudWatch Events vs EventBridge
CloudWatch Events and EventBridge are two AWS services that allow you to manage and process events in the cloud. However, there are some differences between the two services:
- Purpose: CloudWatch Events is primarily used for monitoring, auditing, and logging AWS resource changes, while EventBridge is used for connecting and routing events between different AWS services and third-party applications.
- Event Sources: CloudWatch Events supports events generated by AWS services, while EventBridge supports a wider range of event sources, including AWS services, custom applications, and SaaS applications.
- Event Routing: Both services allow you to route events to their intended targets, but EventBridge provides a more flexible and scalable rule-based system for routing events, whereas CloudWatch Events supports a more limited set of event routing options.
- Serverless: EventBridge is a serverless service, meaning you do not have to manage any infrastructure to process events. CloudWatch Events, on the other hand, can be used in both serverless and non-serverless configurations.
SNS vs EventBridge
Simple Notification Service (SNS) and EventBridge are both AWS services that allow you to publish and subscribe to events in the cloud. However, there are some differences between the two services:
- Purpose: SNS is a messaging service that allows you to send messages to multiple subscribers, whereas EventBridge is an event bus that enables you to route events from different sources to their intended targets.
- Event Sources: SNS supports publishing events from any source, while EventBridge is designed to support a wide range of event sources, including AWS services, custom applications, and SaaS applications.
- Subscriber Types: SNS supports multiple subscriber types, including HTTP/HTTPS, email, SMS, and Lambda functions, while EventBridge supports Lambda functions, S3 buckets, EC2 instances, and other AWS services as targets for events.
- Rule-Based Routing: EventBridge uses a rule-based system to route events to their intended targets, making it a more flexible and scalable solution for processing events. SNS does not have a similar feature, instead relying on subscribers to filter the events they receive.
Kinesis vs EventBridge
Amazon Kinesis and EventBridge are two AWS services that allow you to process streaming data in the cloud. However, there are some differences between the two services:
- Purpose: Kinesis is a managed service for real-time processing of streaming data, while EventBridge is an event bus that enables you to route events from different sources to their intended targets.
- Event Processing: Kinesis provides the ability to process large amounts of streaming data in real-time using consumer applications, while EventBridge allows you to route events to their intended targets using a rule-based system.
- Scalability: Kinesis provides scalable and highly available streaming data processing capabilities, while EventBridge provides scalable and flexible event routing capabilities.
- Event Sources: Kinesis supports events generated by custom applications, while EventBridge supports a wider range of event sources, including AWS services, custom applications, and SaaS applications.
AWS EventBridge Building Blocks
Before delving into the inner workings of EventBridge, let us first examine the components that make up this service:
Events – An event is a change that occurs in real-time in a system, data, or environment. This modification can occur in your application, an AWS service, or a SaaS partner service.
Event sources – An event source is used to ingest events to an AWS customer account from a SaaS partner or your app.
Event buses – To receive events from event sources, you must establish an event bus in your AWS account. These event buses come in a variety of styles:
- Default event bus — This is the default event bus, and it receives events from any AWS service.
- Custom event bus – Receives events from custom apps that you design and must be manually created.
- Partner event bus — This bus receives events from SaaS partner apps and must be manually setup.
Furthermore,
Rules — A rule is generated and connected with an event bus, from which the events to be matched are scanned. When incoming events fit the rule, they are forward to targets for processing. You can also enable Parallel processing by routing to many destinations. A rule can also parse JSON and filter/customize it to deliver just specific sections of JSON or to rewrite content.
Targets – A target is an event processor. For events, it supports the JSON format. AWS services such as Amazon EC2 instances, Lambda functions, Kinesis streams, Amazon ECS tasks, Step Functions, Amazon SNS topics, and Amazon SQS may all be targets.
How EventBridge Works
Amazon EventBridge, in layman’s terms, is a serverless event bus that supports the publish/subscribe approach. SaaS apps provide events to this event bus, which distributes them to one or more AWS target services.
The first step is to write out a rule. A rule must be in the same region as the target. An event pattern must be present in order for a rule to exist. It uses the pattern to match the incoming events. An illustration of how to handle all EC2 instance termination events is shown below:
Each rule must be link to an event bus. You can choose one of the event buses depending on the criteria described above. Now, choose a target to which the events will direct; if the rule matches the event pattern.
The following stage is to design an event bus. Every AWS account has one default event bus that accepts events from AWS services. Custom apps can also configure to transmit events to the default event bus. You can establish a partner event bus if you need to interface with a SaaS partner application.
After you’ve configured the basic flow, you may activate features like content-based event filtering, altering target inputs, schema registry, and so on.
Content-based event filtering
Complex rules are written in content-based event filtering; to allow events to handle when filtering requirements get fulfil. For example, you could wish to pass the event only if it lacks a specified field or if it originates from a specific IP address. It supports the following pattern matching types:
- Matching of Prefixes
- Everything except Matching
- Matching by Numbers
- IP Address Verification
- Exists Matching
- Complex Example with Multiple Matching
EventBridge Schema Registry
We’ve seen how events are released and digested by targets so far. However, if you need to read these events at the target end and handle them; you must now manually create code that matches the event format being received.
AWS released Schema Registry to consolidate and distribute the event structure; which can be download as objects with common programming languages like Java and Python, to address this issue. These schemas can be in use to produce events as well as code binding.
Additional Information
Here are some other considerations to keep in mind while you create EventBridge for your serverless applications:
- EventBridge is price similarly to CloudWatch Events, at $1 per 1 million events broadcast to the event bus.
- EventBridge will guarantee that objectives are meet. If there is a failure, it will attempt for 24 hours before labelling it as unsuccessful. In the case of Lambda, successful delivery implies that the EventBridge was able to asynchronously call your function. As long as EventBridge receives a 200 answer, the transaction is consider successful. If Lambda execution fails, it must respond using the Lambda retry policy. EventBridge’s retry strategies are ineffective.
- EventBridge connects an AWS service from one AWS account to another AWS service in a separate account in a seamless manner. It has an aim of “event bus from another account.”
- EventBridge requires SQS to provide resilience, whereas Kinesis has this feature by default.
What Came Before EventBridge?
EventBridge is primarily for addressing issues with SaaS platform connection with AWS services. This is crucial since, in today’s cloud environment, SaaS platforms like as CRMs, identity providers, and so on have become critical partners. They create a vast volume of data that is sent to AWS systems for business processing. Before EventBridge, there were only two options for transmitting event data to AWS:
Pollin
We often use a Cron job or CloudWatch Scheduler to contact the SaaS APIs using this approach. It will check to see whether there has been any change in the data before retrieving it. Polling frequency might range from minutes to hours, depending on the use case and the capacity of the SaaS platform to handle the traffic.
SaaS Webhooks
This method eliminates the issue of data freshness. In this section, we discover an HTTP endpoint of the AWS-hosted application that the SaaS platform may use to deliver event data. When records update, the SaaS platform will activate the webhooks and provide real-time data.
Final Words
Amazon EventBridge is a powerful and flexible event-driven service that enables you to build scalable and responsive applications. It simplifies the process of building event-driven architectures by providing a fully managed service that connects different AWS services, third-party SaaS applications, and custom applications.
With EventBridge, you can define rules to process events and trigger actions in response to specific events, making it easy to automate workflows and build responsive applications. The pre-built event patterns and schema registry make it easier to integrate new services and manage your event data.
The advent of EventBridge aids in resolving some of the major challenges associated with SaaS platform interaction with AWS services. In addition, interaction with current AWS services has been simpler and smoother. When compared to other AWS services, it’s evident that, while CloudWatch Events, SNS, and Kinesis all have their merits, EventBridge has the potential to be a vital component of a contemporary, highly distributed microservices architecture.
