Short for transaction processing monitor, a program that monitors a transaction as it passes from one stage in a process to another. The TP monitor's purpose is to ensure that the transaction processes completely or, if an error occurs, to take appropriate actions.
TP monitors are especially important in three-tier architectures that employ load balancing because a transaction may be forwarded to any of several servers. In fact, many TP monitors handle all the load balancing operations, forwarding transactions to different servers based on their availability.
