![]() ![]() For example, spent considerable effort to ensure that when its first thousand Xboxes went on sale, each of the 50,000 customers who were vying for an Xbox had a fair chance to get one. At a rock concert, when dozens of operations are competing to reserve the same remaining seats, it’s important that only one customer is assigned to each seat. Uncontrolled concurrent transactions can generate wrong answers. To scale up a system for high performance, transactions must execute concurrently. Yet companies want to serve their customers quickly and with the least cost. We’ve all had the experience of being delayed because a sales person is waiting for a cash register terminal to respond or because it takes too long to download a web page. Transaction volume and database size adds complexity and undermines efficiency. However, when scalability, reliability, and cost enter the picture, things can quickly get very complicated. It is easy to imagine a simple program that would do this work. One operation records the payment and another operation records the commitment to ship the item to the customer. For example, consider the purchase of an item from an on-line catalog. There are many requirements on computer-based transaction processing, such as the following: ■Ī business transaction requires the execution of multiple operations. ![]() This is transaction processing (TP)-the processing of business transactions by computers connected by computer networks. communications between the parties involved in the business transaction is often done over a computer network, such as the Internet. ![]() Often this bookkeeping is done by a computer, for better scalability, reliability, and cost. Usually some bookkeeping is required to record what happened. For example, it could involve exchanging money, products, information, or service requests. Read moreĪ business transaction is an interaction in the real world, usually between an enterprise and a person or another enterprise, where something is exchanged. The following sections detail roles played by BTP elements and the nature and content of BTP messages. The superior informs the inferior when to prepare to terminate the transaction and waits for the inferior to report back on the result of its request. The BTP element associated with the application element that starts a business transaction is usually assigned the superior role. The initiator and terminator of a transaction are usually played by the same application element.īTP elements play either a superior or inferior role. With respect to a BTP transaction, application elements play the role of initiator (the Web service that starts the transaction) and terminator (the Web service that decides to commit or end the transaction). These elements may or may not coexist in a single address space. The separation of system components into BTP and application elements is a logical one. The BTP elements are supplied by the BTP vendor. The application element pertains to the service consumer and service producer components the application programmer deploys–that is, application/business logic. The BTP elements of the two services also exchange messages that help compose, control, and coordinate a reliable outcome for the message sent between the application elements. When Flute Bank's bill payment service sends a message to the check writing service with details of the payee's name, address, and payment amount, the application elements of the two services are exchanging a message. The application elements exchange messages to accomplish the business function.
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