apache/iceberg · error · IllegalArgumentException

Invalid operator event type:

Error message

Invalid operator event type: 

What it means

TriggerManagerCoordinator.handleEventFromOperator handles OperatorEvents from maintenance subtasks on the coordinator side. It only accepts LockRegisterEvent; any other event type produces this IllegalArgumentException, wrapped by Tasks.foreach with subtask/attempt context. It signals the coordinator received an event it was not designed to process.

Source

Thrown at flink/v2.2/flink/src/main/java/org/apache/iceberg/flink/maintenance/operator/TriggerManagerCoordinator.java:48

  TriggerManagerCoordinator(String operatorName, Context context) {
    super(operatorName, context);
    LOG.info("Created TriggerManagerCoordinator: {}", operatorName);
  }

  @Override
  public void handleEventFromOperator(int subtask, int attemptNumber, OperatorEvent event) {
    runInCoordinatorThread(
        () -> {
          LOG.debug(
              "Handling event from subtask {} (#{}) of {}: {}",
              subtask,
              attemptNumber,
              operatorName(),
              event);
          if (event instanceof LockRegisterEvent) {
            registerLock((LockRegisterEvent) event);
          } else {
            throw new IllegalArgumentException(
                "Invalid operator event type: " + event.getClass().getCanonicalName());
          }
        },
        String.format(
            Locale.ROOT,
            "handling operator event %s from subtask %d (#%d)",
            event.getClass(),
            subtask,
            attemptNumber));
  }
}

View on GitHub (pinned to 86d9c8fc54)

Solutions

1. Send only LockRegisterEvent to TriggerManagerCoordinator; route LockReleaseEvent to LockRemoverCoordinator.
2. Use matching Iceberg versions when restoring from savepoints so event classes line up.
3. Review custom code paths that fetch the coordinator's OperatorEventGateway.

if (!(event instanceof LockRegisterEvent)) {
  LOG.warn("Ignoring unexpected event at TriggerManagerCoordinator: {}", event.getClass());
  return;
}

boolean isLockRegister(OperatorEvent e) { return e instanceof LockRegisterEvent; }

try {
  coordinatorGateway.sendEventToCoordinator(new LockRegisterEvent(lockId));
} catch (IllegalArgumentException e) {
  LOG.error("TriggerManager coordinator rejected event", e);
}

When it happens

Trigger: An OperatorEvent that is not a LockRegisterEvent (e.g. a LockReleaseEvent) is delivered to the TriggerManager coordinator, commonly from a miswired gateway or version-skewed operator event during restore.

Common situations: Mixing Iceberg versions across a savepoint restore, or a bug in event routing where release events are sent to the register coordinator.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• Invalid operator event type:
• Invalid operator event type:
• Invalid operator event type:
• Invalid operator event type:
• Invalid operator event type: <event.getClass().getCanonicalN

AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/977e88bde8d5e581. Report an issue: GitHub.