我使用服务代理作为我的消息系统来安排和运行作业。 Eash作业由多个任务或称为引擎的步骤组成。
我的服务代理对象是：
我在jobqueue上有内部激活（存储过程）。对于SubmitJob MessageTypes，存储过程获取该作业的第一个任务，启动与EngineService的对话并向该队列发送消息（StartTask）对于TaskResponses MessageType，我检查是否还有该任务的任务，如果有然后他们被提交到EngineQueue，如果没有，那么这个工作的任务就完成了（发送消息并清理。）
这一切看起来都很有效。但是，我希望有一个处理EngineQueue消息的外部应用程序（引擎）。所以我使用微软的外部激活机制（ssbeas.exe。）花了很长时间，但我终于让它工作了。消息进入EngineQueue，EventNotificationEngineQueue将触发我的应用程序并排空队列。到现在为止还挺好。但是，我的应用程序似乎运行了多次。我的测试应用程序配置为在完成后发送电子邮件。即使我只用一个任务发送一份工作，我也会收到多封电子邮件（表示该程序多次运行。）
以下是我的应用程序（vb.net）的代码（代理是封装服务代理服务的对象（发送，接收等）：
While True
oBroker.tran = oBroker.cnn.BeginTransaction
oBroker.Receive("EMGQueue", msgType, msg, serviceInstance, dialogHandle)
If dialogHandle = System.Guid.Empty Then
'Console.WriteLine("An Error Occurred. Program Terminated.")
oBroker.tran.Commit()
Exit While
End If
ConsoleWriteLine("Received: " & msgType)
If (msg Is Nothing) Then
ConsoleWriteLine("commiting and exiting")
oBroker.tran.Commit()
Exit While
Else
Select Case (msgType)
Case "SubmitTask"
ProcessMsg(oBroker.cnn, oBroker.tran, msgType, msg, iTaskID, iTaskKey)
oBroker.Send(dialogHandle, "<TaskStatus>1</TaskStatus>'")
Case "http://schemas.microsoft.com/SQL/ServiceBroker/EndDialog"
oBroker.EndDialog(dialogHandle)
Case "http://schemas.microsoft.com/SQL/ServiceBroker/Error"""
oBroker.EndDialog(dialogHandle)
End Select
End If
ConsoleWriteLine("commiting...")
oBroker.tran.Commit()
End While
我不明白为什么应用程序运行多次但超出了我不明白为什么后续版本仍然能够在队列中看到该消息。毕竟，第一个化身应该将消息锁定在队列中。它确实锁定了队列，因为我能够使用查询管理器进行测试，以便在我的应用程序运行且被阻止时尝试接收消息。
我尝试过使用EAService.config中的并发值。当我把它设置为 min =“0”和max =“1”我确实减少了应用程序似乎减少到2的次数。以前，使用min =“0”和max =“10”，它运行它似乎是18个副本。
我希望这对长度有意义和抱歉。任何人都有任何想法在这里发生了什么？我在.net应用程序编码中犯了错误吗？
由于 马丁
编辑：添加在Engine运行后创建的日志：
2010-02-08 09:31:39 - 主要
2010-02-08 09:31:39 - 收到：SubmitTask
2010-02-08 09:31:39 - ProcessMsg
2010-02-08 09:31:39 - <Task><TaskID> 5</TaskID><TaskKey>2</TaskKey></Task>
2010-02-08 09:31:39 - DoWork
2010-02-08 09:31:39 - 发送电子邮件
2010-02-08 09:31:40 - 承诺...
2010-02-08 09:31:40 - 睡觉了
2010-02-08 09:32:10 - 睡觉完成。
2010-02-08 09:32:10 - 主要完成
2010-02-08 09:32:10 - 外部激活的应用程序成功并立即终止
2010-02-08 09:32:10 - 主要
2010-02-08 09:32:10 - 收到：SubmitTask
2010-02-08 09:32:10 - ProcessMsg
2010-02-08 09:32:10 - <Task><TaskID> 5</TaskID><TaskKey> 2</TaskKey></Task>
2010-02-08 09:32:10 - DoWork
2010-02-08 09:32:10 - 发送电子邮件
2010-02-08 09:32:10 - 承诺...
2010-02-08 09:32:10 - 睡觉
2010-02-08 09:32:40 - 睡觉完成。
2010-02-08 09:32:40 - 主要完成
2010-02-08 09:32:40 - 外部激活的应用程序成功并立即终止。
你可以看到它通过整个应用程序两次（主要，收到，dowork，sendemail，完成。）
编辑2：这是存储过程的最新版本（debuggin语句和所有）在作业提交到队列时被激活：
ALTER PROCEDURE [dbo].[pr_ProcessJob] AS BEGIN
DECLARE @message_type_name sysname
DECLARE @dialog uniqueidentifier
DECLARE @message_sequence_number bigint
DECLARE @error_message_sequence_number bigint
DECLARE @message_body xml
DECLARE @cgid uniqueidentifier
DECLARE @JobID int
DECLARE @Params varchar(MAX)
DECLARE @ErrorNumber bigint
DECLARE @ErrorText nvarchar(MAX)
DECLARE @TaskID int
DECLARE @TaskService varchar(100)
DECLARE @TaskKey int
DECLARE @chEngine uniqueidentifier
DECLARE @Step int
DECLARE @NextStep int
DECLARE @jobch uniqueidentifier
DECLARE @EngineMsg XML
DECLARE @TimeStarted datetime
DECLARE @TaskStatus int
-- This procedure will just sit in a loop processing Task messages in the queue
-- until the queue is empty
SET NOCOUNT ON
SET @error_message_sequence_number = -100
PRINT 'pr_ProcessJob: Start'
WHILE (1=1) BEGIN
BEGIN TRY
PRINT 'pr_ProcessJob: BEGIN TRANSACTION'
BEGIN TRANSACTION
-- first lets get the conversation group id for the next message.
WAITFOR (
GET CONVERSATION GROUP @cgid FROM [JobQueue]
), TIMEOUT 1000
IF (@@ROWCOUNT = 0) BEGIN
PRINT 'pr_ProcessJob: ROLLBACK TRANSACTION (GET CONVERSATION)'
ROLLBACK TRANSACTION
BREAK
END
PRINT @CGID
-- Inner Loop (Message Processing)
WHILE (1=1) BEGIN
-- Receive the next available message
PRINT 'Receiving Message.'
WAITFOR (
RECEIVE top(1) -- just handle one message at a time
@message_type_name=message_type_name, --the type of message received
@message_body=CAST(message_body AS XML), -- the message contents
@message_sequence_number=message_sequence_number,
@dialog = conversation_handle -- the identifier of the dialog this message was received on
FROM [JobQueue]
WHERE conversation_group_id=@cgid
), TIMEOUT 3000 -- if the queue is empty for three seconds, give up and go away
-- If we didn't get anything, the queue is empty so bail out
IF (@@ROWCOUNT = 0) BEGIN
PRINT 'pr_ProcessJob::WaitFor - No messages for conversation group bailing out'
BREAK
END --IF (@@ROWCOUNT = 0)
PRINT 'Message Received: ' + @message_type_name
SAVE TRANSACTION MessageReceivedSavePoint
-- Handle the End Conversation Message
IF (@message_type_name = 'http://schemas.microsoft.com/SQL/ServiceBroker/EndDialog') BEGIN
-- When we receive an End Dialog, we need to end also.
PRINT 'ENDING CONVERSATION'
END CONVERSATION @dialog
END -- IF (@message_type_name = 'http://schemas.microsoft.com/SQL/ServiceBroker/EndDialog') BEGIN
ELSE BEGIN
-- Handle the Conversation Error Message
IF (@message_type_name = 'http://schemas.microsoft.com/SQL/ServiceBroker/Error') BEGIN
-- We can't return anything here because the dialog at the other end is closed so just log
-- an error and close our end of the conversation.
PRINT 'ENDING CONVERSATION w/Error'
END CONVERSATION @dialog
END -- (@message_type_name = 'http://schemas.microsoft.com/SQL/ServiceBroker/Error')
ELSE BEGIN
IF (@message_type_name = 'SubmitJob') BEGIN -- Process normal Job messages..
PRINT 'pr_ProcessJob:: Message Type SubmitJob received.'
-- Pull the information out of the task message with XQuery
SELECT @JobID = @message_body.value('(/Job/JobID)[1]', 'int'),
@Params = @message_body.value('(/Job/Params)[1]', 'varchar(MAX)')
PRINT 'pr_ProcessJob::@JobID = ' + cast(@jobID as varchar(10))
PRINT 'pr_ProcessJob::@Params = ' + @Params
SELECT @ErrorNumber = 0, @ErrorText = N''
-- Do something with the job
-- save state
-- we are looking for the first step
SET @Step=1
PRINT 'Selecting from JobTask'
---------------------------------------------------------
-- Get the next task
---------------------------------------------------------
SELECT TOP 1
@TaskID=task.TaskID,
@TaskService=tt.TaskService,
@TaskKey =Task.TaskKey
FROM JobTask task INNER JOIN TaskType tt
ON task.TaskTypeID = tt.TaskTypeID
WHERE task.jobID=@JobID AND task.enabled=1 and task.step>=@step
ORDER BY Task.step
---------------------------------------------------------
PRINT 'Selecting from JobTask: complete'
PRINT 'Step='+cast(@step as varchar(max))
PRINT 'TaskID='+cast(@TaskID as varchar(max))
PRINT 'TaskService='+cast(@TaskService as varchar(max))
PRINT'TaskKey='+cast(@TaskKey as varchar(max))
PRINT 'BEGIN DIALOG with ' + @TaskService
BEGIN DIALOG @chEngine
FROM SERVICE [JobService]
TO SERVICE @TaskService
ON CONTRACT [TaskContract]
WITH RELATED_CONVERSATION=@dialog;
PRINT 'BEGIN DIALOG with ' + @TaskService+' completed.'
SET @EngineMsg = CAST('<Task><TaskID>'+ str(@TaskID)+'</TaskID><TaskKey>'+ str(@Taskkey)+'</TaskKey></Task>' as XML);
PRINT CAST(@EngineMsg as varchar(max))
PRINT 'Sending Message Type SubmitTask to Engine.';
SEND ON CONVERSATION @chEngine
MESSAGE TYPE SubmitTask
(@EngineMsg)
PRINT 'Inserting into jobstate'
INSERT INTO JobState(cgid, jobch, jobID, step) VALUES(@cgid, @dialog, @jobid, @step)
END -- IF (@message_type_name = 'SubmitJob')
ELSE BEGIN
IF (@message_type_name = 'TaskResponse') BEGIN
PRINT 'Processing MessageType TaskResponse'
SELECT @TaskStatus = @message_body.value('(/TaskStatus)[1]', 'int')
PRINT 'pr_ProcessJob::@TaskStatus = ' + cast(@TaskStatus as varchar(10))
PRINT 'Loading State'
--LoadState
SELECT @JobID=jobid,
@Step=Step,
@jobch=jobch,
@TimeStarted=sysdate
FROM Jobstate
WHERE cgid=@cgid
PRINT 'Loading State complete'
PRINT @jobch
PRINT 'Selecting from JobTask'
---------------------------------------------------------
-- Get the next task
---------------------------------------------------------
SELECT TOP 1
@TaskID=task.TaskID,
@TaskService=tt.TaskService,
@TaskKey =task.TaskKey,
@NextStep = task.Step
FROM JobTask task INNER JOIN TaskType tt
ON task.TaskTypeID = tt.TaskTypeID
WHERE task.jobID=@JobID AND task.enabled=1 and task.step>@step
ORDER BY Task.step
---------------------------------------------------------
PRINT 'Selecting from JobTask: complete'
PRINT 'NextTask: ['+@TaskService+']'
if (@TaskService is null) BEGIN
PRINT '@TaskService is NULL: BEGIN'
-- no more tasks
--END CONVERSATION @jobch
PRINT 'Removing from state table'
DELETE FROM JobState
WHERE @cgid=cgid
PRINT @@ROWCOUNT
PRINT 'Removing from state table-completed'
DECLARE @ResponseDoc xml
-- Send a response message saying we're done
DECLARE @Time nvarchar(100)
SET @Time = cast(getdate() as nvarchar(100))
DECLARE @TimeStartedText nvarchar(100)
SET @TimeStartedText = cast(@TimeStarted as nvarchar(100))
SET @ResponseDoc = N'<Job/>'
SET @ResponseDoc.modify(
'insert (<JobID>{ sql:variable("@JobID") }</JobID>,
<JobStatus>{ sql:variable("@ErrorNumber") }</JobStatus>,
<ErrorNumber>{ sql:variable("@ErrorNumber") }</ErrorNumber>,
<ErrorText>{ sql:variable("@ErrorText") }</ErrorText>,
<TimeStarted>{ sql:variable("@TimeStartedText") }</TimeStarted>,
<TimeCompleted>{ sql:variable("@Time") }</TimeCompleted>)
as last into /Job [1]');
SEND ON CONVERSATION @jobch
MESSAGE TYPE [JobResponse] (@ResponseDoc)
END CONVERSATION @jobch
PRINT '@TaskService is NULL: END'
END --if (@TaskService is null) BEGIN
ELSE BEGIN
-- there are more tasks
PRINT '@TaskService is not null: BEGIN'
PRINT 'BEGIN DIALOG with ' + @TaskService
--another task
BEGIN DIALOG @chEngine
FROM SERVICE [JobService]
TO SERVICE @TaskService
ON CONTRACT [TaskContract]
WITH RELATED_CONVERSATION=@dialog;
SET @EngineMsg = CAST('<Task><TaskID>'+ str(@TaskID)+'</TaskID><TaskKey>'+ str(@Taskkey)+'</TaskKey></Task>' as XML);
PRINT 'SEND ' +cast(@EngineMsg as varchar(max));
SEND ON CONVERSATION @chEngine
MESSAGE TYPE SubmitTask (@EngineMsg)
PRINT 'SAVING State: ' +str(@step)
-- save state
Update JobState
SET step = @NextStep
FROM JobState
WHERE cgid=@cgid
PRINT '@TaskService is not null: END'
END -- ELSE (@TaskService is NOT NULL)
PRINT 'Processing MessageType TaskResponse...Complete'
END -- IF (@message_type_name = 'TaskCompleted')
END -- ELSE IF (@message_type_name <> 'JobRequest')
END -- ELSE (@message_type_name <> 'http://schemas.microsoft.com/SQL/ServiceBroker/Error')
END -- ELSE (@message_type_name <> 'http://schemas.microsoft.com/SQL/ServiceBroker/EndDialog')
END -- WHILE (1=1) BEGIN
PRINT 'COMMIT TRANSACTION'
COMMIT TRANSACTION
END TRY
BEGIN CATCH
--rollback transaction
DECLARE @ErrNum int
DECLARE @ErrMsg varchar(max)
SELECT
ERROR_NUMBER() AS ErrorNumber
,ERROR_SEVERITY() AS ErrorSeverity
,ERROR_STATE() AS ErrorState
,ERROR_PROCEDURE() AS ErrorProcedure
,ERROR_LINE() AS ErrorLine
,ERROR_MESSAGE() AS ErrorMessage;
PRINT 'pr_ProcessJob: ROLLBACK (CATCH)'
if (error_number()=1205) BEGIN
-- a deadlock occurred. We can try it again.
PRINT 'pr_ProcessJob: ROLLBACK TRANSACTION (CATCH)'
ROLLBACK TRANSACTION
--CONTINUE
END --if (error_number()=1205)
ELSE BEGIN
if (error_number()=9617) BEGIN
PRINT 'pr_ProcessJob: ROLLBACK TRANSACTION (CATCH)'
ROLLBACK TRANSACTION
END
ELSE BEGIN -- (error_number()<>9617)
-- another error occurred. The message cant be procesed sucessfully
PRINT 'pr_ProcessJob: ROLLBACK TRANSACTION to MessageReceivedSavePoint (CATCH)'
ROLLBACK TRANSACTION MessageReceivedSavePoint
END --ELSE (error_number()<>9617)
END -- if (error_number()<>1205)
END CATCH
END -- while loop
PRINT 'pr_ProcessJob: Complete'
END -- CREATE PROCEDURE [dbo].[ProcessJobProc]
答案 0 :(得分：1)
如果您的应用的后续实例能够看到该消息，则仅表示一件事：前一个实例必须已回滚接收。乍一看，您提供的代码看起来没问题，所以我会去查找您正在使用的对象模型中的错误。如果其中一个方法抛出异常，则应用程序将被终止，并且收到该消息的事务将自动回滚。
如果您希望一次只运行一个应用程序实例，请将Max设置保持为1，否则默认情况下会同时运行更多实例以跟上负载。