In n-tier architecture, the clients and servers can be placed at distant locations. The server that implements business logic can provide services to various clients. In such a scenario, it is essential to ensure asynchronous communication. | Implementing Services for Message-Based Communication Chapter 11 In n-tier architecture the clients and servers can be placed at distant locations. The server that implements business logic can provide services to various clients. In such a scenario it is essential to ensure asynchronous communication. This allows the client applications to send requests even if the server is not available to process the requests immediately. SQL Server 2005 allows you to implement this by using service broker. Service Broker is a feature provided by SQL Server that provides a platform on which the services interact by sending and receiving messages. Services are self-contained components that provide a required functionality. This chapter provides an overview of message-based communication. Further it explains how to implement services for a message-based communication. Objectives In this chapter you will learn to fl Appreciate message-based communication fl Implement Service Broker Message-Based Communication Consider a scenario of credit card services. When a person makes a purchase through a credit card the credit card details are validated and a purchase transaction is completed. In addition an entry is made in the database of the bank that issued the credit card for an amount that the person had to pay for the transaction. At the end of a period a consolidated bill is sent to the person to receive the credited amount. In this scenario there is also a possibility of the client application not being able to connect to the database. Therefore it is required to build a reliable system to ensure that all the requests sent to the server will be processed. SQL Server 2005 provides the developers with Service Broker. Service Broker is a message-based communication platform that helps in maintaining reliable query processing and asynchronous communication. Introduction to Service Broker Service Broker allows the database developers to create services that converse with each other by .
