Optimistic transmission flow control including receiver data discards upon inadequate buffering condition

An article of manufacture comprising a computer useable medium having computer readable program code means embodied therein for flow-controlling a plurality of sequential messages from a source node into a destination node in a message processing system, each of the plurality of messages including a first data portion and related control information including respective identifying indicia thereof, the computer readable program code means in said article of manufacture comprising:

• code means for initially transmitting the respective data portions and the respective control information of a first message and at least one subsequent message of the plurality of messages from the source node to destination node;
• and
• code means for, in response to the destination node receiving but being unable to retain, due to conditions therein, the data portion of the first message:
• the destination node discarding the data portion of the first message but retaining the identifying indicia of the control information thereof, and sending a negative acknowledgment relating to the first message to the source node using said control information, and
• until it is able to retain, due to changed conditions therein, any data portions of messages, the destination node discarding respective data portions of the at least one subsequent message as they are received thereby but retaining the respective identifying indicia of the respective control information thereof, and sending respective negative acknowledgments relating thereto to the source node using said respective control information.