Managing Exceptions and Resubmissions in Events

We have two questions/proposals:

1. Exception Handling in Event Listeners

Is there any way to control exceptions thrown within event listeners?

We’re using events to communicate between modules, but we’re unsure how to properly manage the different types of exceptions that may be thrown by a module.

We’re currently dealing with two types of exceptions:

• Retryable exceptions – should trigger a resubmission.
• Non-retryable exceptions – should mark the event as failed.

We attempted to handle this by creating an aspect that marks the event as failed. However, the only way we found to prevent an exception from being retried was to simulate multiple attempts until the scheduler stops picking up the event—based on resubmission options with a high attempt count. This approach feels quite hacky and not clean.

Additionally, we noticed that unless the exception is rethrown, Modulith marks the event as completed—even if we explicitly marked it as failed. This behavior seems counterintuitive.

Is there anything on the roadmap regarding better exception management for events?

2. Controlling Resubmission Behavior by Event Type

How can we control resubmission strategies based on different event types?

For example:

• EventA should be resubmitted based on a duration.
• EventB should be resubmitted based on completion attempts.

We explored ResubmissionOptions and the withFilter method, but couldn’t find a way to differentiate behavior based on event type.

Would it be feasible to expose the event type in the EventPublication object?
That could allow more granular control over resubmission logic.

Thanks in advance for your feedback!

Start by reading ResubmissionOptions, its withFilter method, and EventPublication, then trace how listener exceptions and resubmissions are currently handled. The issue needs maintainer clarification before work can begin: whether exception classification, event-type-specific strategies, or exposing event type is wanted, along with the expected behavior and tests.