Operating Systems: Concurrent and Distributed Software Design

30.1. Transaction processing monitors

Transaction processing applications were introduced in Chapter 1 and the theory underlying the correct execution of transactions was the core topic of Part III. A TP monitor coordinates the flow of information between users at terminals who issue transaction requests and TP applications that process the requests. Much of the integration of the software components (operating systems, communications and database management systems (DBMSs)) that are used by TP applications is done by the TP monitor. Figure 30.1 gives a model for a TP monitor, which follows Bernstein (1990). It is assumed that each transaction selects a pre-specified application service program. This is in contrast with a database transaction, ...