AWS Introduces Enhanced Custom Event Buses for Organization-Wide Event Sharing

AWS has released an enhanced custom event bus for Amazon EventBridge, designed to simplify event-driven architectures across multiple AWS accounts. Unlike the previous model that required complex cross-account routing and bus-to-bus configurations, this new resource allows a single centralized bus to be shared across an entire organization using AWS Resource Access Manager (AWS RAM).

Core Capabilities

The enhanced bus introduces several key features to address operational complexity and performance needs:

• Organization-Wide Sharing: Platform teams can deploy one bus as a central backbone, allowing application teams to publish and subscribe without configuring cross-account permissions. The default quota is 10,000 Subscribers per bus, with options to request higher limits.
• Event Ordering: Publishers can include an EventGroupId to ensure events with the same ID are delivered in sequence. This supports synchronous invocation for targets like AWS Lambda, eliminating the need for intermediate Amazon SQS queues for reliability.
• Simplified Subscriptions: A new Subscriber resource consolidates filtering, target configuration, retry policies, and dead-letter destinations into a single unit, replacing the previous need to manage separate rules and targets.

Data Handling and Pricing

The update includes advanced data processing features and a revised pricing structure:

• Content-Based Deduplication: EventBridge can hash event payloads to detect and drop retries within a five-minute window, providing exactly-once delivery semantics for sources that cannot reliably identify duplicate events.
• Event Transformation: Subscribers can use JSONata expressions to reshape events before delivery. The system also supports deserializing Apache Avro and Protocol Buffers payloads to JSON for fine-grained filtering.
• New Pricing Model: Costs are now based on ingress and egress throughput rather than per-event routing. Publishers pay for ingested events, and subscribers pay for delivered events, aiming to reduce the compounding costs of multi-bus architectures.

Availability

The enhanced custom event bus is available today in US East (N. Virginia, Ohio), US West (Oregon), Europe (Ireland, Frankfurt, Stockholm, Spain), and Asia Pacific (Hong Kong, Malaysia, Mumbai, Singapore, Sydney, Thailand, Tokyo). Existing custom event buses remain available as Custom event bus – classic and require no changes.