這里演示同一個SQL Server中不同數據庫之間的基于Service Broker的異步消息傳遞，其中Stored Procedure充當Service Program。HelloWorldDB為目標數據庫，DotNetFun2則為消息發送發的數據庫。
同時，假設Server Broker的基本對象類型已經創建，如MessageType(XMLMessage), Contract(XMLContract), Queue(SendingQueue and ReceivingQueue)等等，具體操作可以參考《A simple tutorial on SQL Server 2005 Beta 2 Service Broker》。另外，因為在不同的Databases之間進行消息傳遞，因此需要創建Route，具體操作可以參考《SQL Server 2005 Beta 2 Service Broker: Create Route》。
1.創建Stored Procedure作為Internal Service Program.
USE HelloWorldDBGOAlter Procedure HelloWorldResponderAsBeginDeclare @conversationHandle UNIQUEIDENTIFIERDeclare @message_body nvarchar(MAX)Declare @message_type_name SYSNAMEWHILE (1=1)BEGINBEGIN TRANSACTION-- Wait for 1 seconds for messages to arriveWAITFOR (-- For simplicity we process one message at a timeRECEIVE TOP(1)@message_type_name=message_type_name,@conversationHandle=conversation_handle,@message_body=message_bodyFROM [ReceivingQueue]), TIMEOUT 1000-- If a message was received, process it, else skipIF (@@rowcount <= 0)BREAK;-- If this is a XML message,-- respond with an appropriate greetingIF @message_type_name = 'XMLMessage'BEGINSEND ON CONVERSATION @conversationHandleMESSAGE TYPE XMLMessage('Hello From Rickie')END CONVERSATION @conversationHandleENDCOMMITENDCOMMITENDGO |
該Stored Procedure負責從ReceivingQueue中檢索消息，并根據Queue的Retention設置，來確定從Queue中移除消息或更新Queue中消息的狀態。
2.設置目標隊列（Target Queue）的激活機制
Use HelloWorldDBgoALTER QUEUE [ReceivingQueue] WITHACTIVATION (STATUS = ON, -- Turn on internal activationPROCEDURE_NAME = [HelloWorldResponder], -- Our stored procMAX_QUEUE_READERS = 4, -- Up to 4 concurrent readersEXECUTE AS SELF) -- Execute as user of incoming dialog |
設置上述創建的Stored Procedure，該Stored Procedure將被激活并處理Queue中的消息。
3.在Initiator端發送消息
Use DotNetFun2goDECLARE @conversationHandle uniqueidentifierBEGIN TRANSACTION-- Begin a dialog to the Hello World ServiceBEGIN DIALOG @conversationHandleFROM SERVICE [SendingService]TO SERVICE 'ReceivingService','a727462b-52e7-4405-9eee-d19923729790'ON CONTRACT [XMLContract]WITH ENCRYPTION = OFF, LIFETIME = 600;-- Send messageSEND ON CONVERSATION @conversationHandleMESSAGE TYPE [XMLMessage]('Welcome to Rickie Lee''s blog, www.cnblogs.com/rickie');Select * From sys.conversation_endpointsCOMMIT |
其中，TO SERVICE 'ReceivingService','a727462b-52e7-4405-9eee-d19923729790'，’ReceivingSerice’表示目標Service名稱，'a727462b-52e7-4405-9eee-d19923729790'則指定目標Service所在的數據庫，可以通過如下SQL Script獲取：
-- Retrieve remote broker instance guidSELECT service_broker_guidFROM sys.databasesWHERE database_id = DB_ID('HelloWorldDB') |
另外，可以通過如下的SQL script來檢測Initiator端收到的Reply消息：
Select cast(message_body as XML) From SendingQueueReceive message_type_name,cast(message_body as XML)From SendingQueue |
4.查詢對話端點狀態（State of Conversation Endpoints）
最后，可以通過在Target/Initiator端查詢sys.conversation_endpoints表，獲取Dialog對話狀態：
Select * From sys.conversation_endpoints |
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