SQL SERVER – Introduction to Service Broker and Sample Script

Service Broker in Microsoft SQL Server 2005 is a new technology that provides messaging and queuing functions between instances. The basic functions of sending and receiving messages forms a part of a “conversation.” Each conversation is considered to be a complete channel of communication. Each Service Broker conversation is considered to be a dialog where two participants are involved.

Service broker find applications when single or multiple SQL server instances are used. This functionality helps in sending messages to remote databases on different servers and processing of the messages within a single database. In order to send messages between the instances, the Service Broker uses TCP/IP.

This transaction message queuing system enables the developers to build secure and reliable applications, which are scalable. The developers can design applications from independent components known as “services.” If the applications need to avail the functionality of these services, then it sends message to the particular “service.”

Loosely coupled applications (programs that exchange messages independently) are supported by the Service broker. The three components of the Service broker are as follows: conversation components (which consist of the conversation groups, conversations and messages); service definition components (which define the conversations); and networking and security components (defines the infrastructure used for exchanging messages between instances)

The maintenance of Service Broker is easy and it is a part of the routine database administration procedure. This is because this functionality forms a part of the Database Engine. Service Broker also provides security by preventing unauthorized access from networks and by message encryption.

Let us understand Service Broker with simple script. Script contains necessary comments to explain what exactly script is doing.

---------------------------- Service Broker -----------------------
-- In this exercise we will learn how to cofigure Servie Broker and send and recieve messages.
-------------------------------------------------------------------CREATE DATABASE ServiceBrokerTest
GOUSE ServiceBrokerTest
GO-- Enable Service BrokerALTER DATABASE ServiceBrokerTest SET ENABLE_BROKER
GO-- Create Message TypeCREATE MESSAGE TYPE SBMessage
VALIDATION = NONE
GO-- Create ContractCREATE CONTRACT SBContract(SBMessage SENT BY INITIATOR)GO-- Create Send QueueCREATE QUEUE SBSendQueue
GO-- Create Receive QueueCREATE QUEUE SBReceiveQueue
GO-- Create Send Service on Send QueueCREATE SERVICE SBSendServiceON QUEUE SBSendQueue (SBContract)GO-- Create Receive Service on Recieve QueueCREATE SERVICE SBReceiveServiceON QUEUE SBReceiveQueue (SBContract)GO-- Begin Dialog using service on contractDECLARE @SBDialog uniqueidentifierDECLARE @Message NVARCHAR(128)BEGIN DIALOG CONVERSATION @SBDialogFROM SERVICE SBSendServiceTO SERVICE 'SBReceiveService'ON CONTRACT SBContractWITH ENCRYPTION = OFF-- Send messages on DialogSET @Message = N'Very First Message';SEND ON CONVERSATION @SBDialogMESSAGE TYPE SBMessage (@Message)SET @Message = N'Second Message';SEND ON CONVERSATION @SBDialogMESSAGE TYPE SBMessage (@Message)SET @Message = N'Third Message';SEND ON CONVERSATION @SBDialogMESSAGE TYPE SBMessage (@Message)GO-- View messages from Receive QueueSELECT CONVERT(NVARCHAR(MAX), message_body) AS MessageFROM SBReceiveQueue
GO-- Receive messages from Receive QueueRECEIVE TOP(1) CONVERT(NVARCHAR(MAX), message_body) AS MessageFROM SBReceiveQueue
GO-- Receive messages from Receive QueueRECEIVE CONVERT(NVARCHAR(MAX), message_body) AS MessageFROM SBReceiveQueue
GO-- Clean UpUSE master
GODROP DATABASE ServiceBrokerTest
GO

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Let me know what do you think of this script and how simply one can configure service broker.