1. A method for resending messages comprising: determining if a particular message with a first unique identifier has been received by a number of potential recipient tasks in a distributed streaming system; in response to all of the number of potential recipient tasks not receiving the particular message, blocking the particular message; determining whether to resend the particular message; in response to determining to resend the particular message, notifying the number of potential recipient tasks to ignore the particular message with the first unique identifier; unblocking the particular message; and resending the particular message with a second unique identifier.