Retry with custom logic

[krezchikov42]

Hello there.
Let's say I am doing a redis mget on a 1000 events. For some reason it is able to fetch 980 events, but it it doesn't find 20 events. We can safely assume that this is because of replication lag. I would then like to retry on these last 20 events up to 3 times within a 3 second period to get those responses back. This use case is more complicated than I believe .onFailure().retry().atMost(2) or anything in this doc allows for because that would have you retry the whole 1000 event request. Does anyone have any ideas on how you could do something like this?
Just being able to retry on a uni without failing would be helpful as well, but even that confuses me without doing an await.

[krezchikov42]

This is an attempt I had to do retries myself, but I don't think this would work correctly.

	public Uni<Optional<Event>> retryGetEvent(String key, int maxAttempts, int initialDelayMs) {
		return Uni.createFrom().deferred(() -> {
			Uni<Optional<Event>> uni = getEvent(key);
			for (int attempt = 1; attempt <= maxAttempts; attempt++) {
				int finalAttempt = attempt;
				uni = uni.onItem().transformToUni(event -> {
					if (event.isPresent()) {
						return Uni.createFrom().item(event); // Success, return the event
					} else if (finalAttempt < maxAttempts) {
						int delay = initialDelayMs * (1 << (finalAttempt - 1)); // Exponential backoff
						LOGGER.warnf("Event not found, retry attempt %d with delay %d for event with key: %s", finalAttempt, delay, key);
						return Uni.createFrom().voidItem().onItem().delayIt().by(Duration.ofMillis(delay))
								.onItem().transformToUni(ignored -> getEvent(key));
					} else {
						return Uni.createFrom().item(Optional.empty()); // All retries exhausted, return empty
					}
				});
			}
			return uni;
		});
	}

where this is the signature for getEvent is where I'm at for being able to retry myself on just a single get request, but I don't think this code would work directly since the last uni would always just the latest uni with the most delay?