3.1 Oracle Tuxedo CORBA Overview

Oracle Tuxedo CORBA provides businesses and organizations that depend on mission-critical applications with the advantages of the CORBA-compliant programming model, combined with the power, robustness, and proven reliability of the Tuxedo transaction processing technology. Oracle Tuxedo CORBA also taps into the existing Tuxedo infrastructure for transaction management, security, message transport, administration and manageability, and XA-compliant database support. Oracle Tuxedo CORBA combines the ORB model with online transaction processing (OLTP) functions to create a top-of-the-line Object Transaction Monitor (OTM).

As shown in the following figure, an OTM is an example of a 3-tier client/server architecture, where the OTM supports the application logic between the GUI front-end and the back-end resource managers. Examples of resource managers are object-oriented databases, relational databases, message queues, legacy applications, and other back-end services.

Figure 3-1 Tier Client/Server Architecture Using an OTM

By breaking the direct connection between the user interface front-end and the resource managers, an OTM controls all the traffic that links hundreds or thousands or even tens of thousands of clients with run-time objects and the back-end resources. An OTM ensures that global (distributed) transactions are completed accurately, provides load balancing, and improves the overall system performance. An OTM also prestarts pools of objects and provides fault-tolerance. More importantly, an OTM makes an application’s server processes independent of the user interface front-end and any resource manager.

Oracle Tuxedo CORBA is an object application server that runs server-side distributed objects. Besides managing an application’s server objects and managing transactions, Oracle Tuxedo CORBA also manages client/server communications.

Object-oriented transactional communications use a highly augmented version of ORB invocations. However, most of the value-added elements are transparent to the programmer: The transactional client/server exchanges look like ordinary exchanges bracketed by start and end transaction calls. The distinguishing factor is that all resource managers and processes invoked through these calls become part of the transaction. An OTM, such as Oracle Tuxedo CORBA, orchestrates the actions of all the participants and makes them act as part of a transaction.