I think it depends on how you interpret "rely". If your app can gracefully recover to a reasonable state from a failure to resume the expected session, then you

I think it depends on how you interpret "rely". If your app can gracefully recover to a reasonable state from a failure to resume the expected session, then you could argue it's not that reliant on it. Many systems use sticky sessions as simply as an optimization, which is fine. You didn't actually give an complete example. When are sticky sessions a better choice than persistence?