Initiator Queue – Ritesh Shah (Extreme-Advice.Com)

Setup service broker between two databases in SQL Server.

My earlier article “Service Broker implementation between two tables in one database” explained how to setup service broker between two table in one database. Today I am explaining how to setup service broker between two tables resides in two different databases in one SQL Server instance.

I will be using the same table, queues, contracts, services and message types given in “Service Broker implementation between two tables in one database” article so if you have not read this article, I would recommend to take a look there once.

Creating two different databases in one SQL Server 2012 instance.

[sourcecode language=”sql”]
USE MASTER;
GO

IF EXISTS (SELECT 1 FROM sys.databases WHERE name = N’ExtremeAdviceSBMain’)
DROP DATABASE ExtremeAdviceSBMain;
GO

CREATE DATABASE ExtremeAdviceSBMain;
GO

IF EXISTS (SELECT 1 FROM sys.databases WHERE name = N’ExtremeAdviceSBReceiver’)
DROP DATABASE ExtremeAdviceSBReceiver;
GO

CREATE DATABASE ExtremeAdviceSBReceiver;
GO

–making broker enable for database.
ALTER DATABASE ExtremeAdviceSBMain SET ENABLE_BROKER
ALTER DATABASE ExtremeAdviceSBMain SET TRUSTWORTHY ON;
ALTER AUTHORIZATION ON DATABASE::ExtremeAdviceSBMain TO [sa];
GO

–making broker enable for database.
ALTER DATABASE ExtremeAdviceSBReceiver SET ENABLE_BROKER
ALTER DATABASE ExtremeAdviceSBReceiver SET TRUSTWORTHY ON;
ALTER AUTHORIZATION ON DATABASE::ExtremeAdviceSBReceiver TO [sa];
GO
[/sourcecode]

Let us now create basic architecture of service broker like message type, contract, queue and services in both databases ExtremeAdviceSBMain & ExtremeAdviceSBReceiver (target and initiator). Please note that I have used the same service broker object I have used in earlier article. We may eliminate few things but I will cover it up later on.

[sourcecode language=”sql”]
USE ExtremeAdviceSBReceiver
GO

–Create Message Type in target database
CREATE MESSAGE TYPE [EXTREME://EX/Message/Order/Request] VALIDATION = WELL_FORMED_XML
CREATE MESSAGE TYPE [EXTREME://EX/Message/Order/Response] VALIDATION = WELL_FORMED_XML
GO

–Create Contract in target database
CREATE CONTRACT [EXTREME://EX/Contract/Order]
(
[EXTREME://EX/Message/Order/Request] SENT BY INITIATOR,
[EXTREME://EX/Message/Order/Response] SENT BY TARGET
);
GO

–Create Target Queue
CREATE QUEUE OrderTargetQueue
WITH STATUS = ON
GO

CREATE SERVICE [EXTREME://EX/Service/Order/Target] ON QUEUE [OrderTargetQueue] ([EXTREME://EX/Contract/Order])
GO

USE ExtremeAdviceSBMain
GO

–Create Message Type in initiator database
CREATE MESSAGE TYPE [EXTREME://EX/Message/Order/Request] VALIDATION = WELL_FORMED_XML
CREATE MESSAGE TYPE [EXTREME://EX/Message/Order/Response] VALIDATION = WELL_FORMED_XML
GO

–Create Contract in initiator database
CREATE CONTRACT [EXTREME://EX/Contract/Order]
(
[EXTREME://EX/Message/Order/Request] SENT BY INITIATOR,
[EXTREME://EX/Message/Order/Response] SENT BY TARGET
);
GO
–Create initiator Queue

CREATE QUEUE OrderInitiatorQueue
WITH STATUS = ON
GO

CREATE SERVICE [EXTREME://EX/Service/Order/Initiator] ON QUEUE [OrderInitiatorQueue] ([EXTREME://EX/Contract/Order])
GO
[/sourcecode]

Now we will create two tables. One table in initiator database which is OrderDetail. Sales person will generate sales order and data will falls under that table. If sales person inserting duplicate order, it will caught by trigger and will be inserted in OrderHistory table. For more detail about this concept, have a look at my earlier article.

[sourcecode language=”sql”]
USE ExtremeAdviceSBMain
GO

–two sample table for demonstration
CREATE TABLE OrderDetail
(
OrderID INT IDENTITY(1,1),
ClientID VARCHAR(10),
ProjectID VARCHAR(50),
OrderDate DATETIME DEFAULT GETDATE()
)
GO

USE ExtremeAdviceSBReceiver
GO

CREATE TABLE OrderHistory
(
ID INT IDENTITY(1,1),
OrderID INT,
DuplicateWith INT,
CheckDate DATETIME DEFAULT GETDATE()
)
GO
[/sourcecode]

Now we will create main logic which will send and process original message along with trigger on OrderDetail table which will activate service broker as soon as new record inserted in OrderDetail table.

[sourcecode language=”sql”]
USE ExtremeAdviceSBMain
GO
–Create this SP in Initiator database
–Create SP which will be called from app
–or trigger or by any other way
–and activate service broker
CREATE PROCEDURE [SendOrderRequestMessage]
(
@data AS XML
)
AS
SET XACT_ABORT OFF;
BEGIN TRY
BEGIN TRANSACTION

DECLARE @DialogHandle UNIQUEIDENTIFIER;

BEGIN DIALOG CONVERSATION @DialogHandle
FROM SERVICE [EXTREME://EX/Service/Order/Initiator]
TO SERVICE N’EXTREME://EX/Service/Order/Target’
ON CONTRACT [EXTREME://EX/Contract/Order]
WITH ENCRYPTION = OFF;

SEND ON CONVERSATION @DialogHandle
MESSAGE TYPE [EXTREME://EX/Message/Order/Request](@data);
–END CONVERSATION @DialogHandle
COMMIT ;

END TRY

BEGIN CATCH
ROLLBACK TRAN;
DECLARE @msg VARCHAR(MAX);
SELECT @msg = ERROR_MESSAGE();
PRINT @msg
END CATCH;
GO

USE ExtremeAdviceSBReceiver
GO

–Create this SP in target database
— Create actual business logic SP
CREATE PROCEDURE [CheckOrderMessage]
(
@data XML
)
AS
BEGIN TRY

DECLARE @MessageType VARCHAR(50)
,@OrderID INT
,@ClientID VARCHAR(10)
,@ProjectID VARCHAR(50)

SELECT @MessageType = @Data.value(‘(OrderMessage/Header/@MessageType)[1]’,’VARCHAR(50)’),
@OrderID = @data.value(‘(OrderMessage/Header/@OrderID)[1]’,’INT’),
@ClientID = @Data.value(‘(OrderMessage/Header/@ClientID)[1]’,’VARCHAR(10)’),
@ProjectID = @data.value(‘(OrderMessage/Header/@ProjectID)[1]’,’VARCHAR(50)’)

SELECT @MessageType = ISNULL(@MessageType,”)

IF @MessageType = ‘OrderHistory’ AND @OrderID IS NOT NULL BEGIN
DECLARE @OrderIDOld INT
,@ClientIDOld VARCHAR(10)
,@ProjectIDOld VARCHAR(50)

SELECT @ClientIDOld=ClientID, @ProjectIDOld=ProjectID, @OrderIDOld=OrderID
FROM ExtremeAdviceSBMain.dbo.OrderDetail
WHERE ClientID=@ClientID AND ProjectID=@ProjectID AND OrderID<>@OrderID

IF(@OrderIDOld IS NOT NULL)
BEGIN
INSERT INTO OrderHistory (OrderID,DuplicateWith)
SELECT @OrderIDOld,@OrderID
END
RETURN
END
END TRY

BEGIN CATCH
DECLARE @msg VARCHAR(MAX)
SELECT @msg = ERROR_MESSAGE()
END CATCH
RETURN
GO

–Create Target queue reader SP
CREATE PROC [OrderTargetQueueReader]
AS
SET NOCOUNT ON;

DECLARE @XML XML,
@MessageBody VARBINARY(MAX),
@MessageTypeName SYSNAME,
@ConversationHandle UNIQUEIDENTIFIER,
@Response XML

BEGIN TRY
WHILE (1 = 1)
BEGIN
WAITFOR (
RECEIVE TOP(1)
@MessageTypeName = message_type_name,
@MessageBody = message_body,
@ConversationHandle = [conversation_handle]
FROM dbo.OrderTargetQueue
), TIMEOUT 60000

IF (@@ROWCOUNT = 0)
BEGIN
BREAK
END
SET @XML = CAST(@MessageBody AS XML);
IF @MessageTypeName = ‘EXTREME://EX/Message/Order/Request’
BEGIN
–PRINT ‘executing CheckOrderMessage @XML’

EXECUTE CheckOrderMessage @XML

–PRINT ‘sending response’

SELECT @xml = ‘OK’;

SEND ON CONVERSATION @ConversationHandle
MESSAGE TYPE [EXTREME://EX/Message/Order/Response](@xml);
–PRINT ‘ending cnversation’
END CONVERSATION @ConversationHandle;
END
END
END TRY
BEGIN CATCH

DECLARE @msg VARCHAR(MAX)
SELECT @msg = ERROR_MESSAGE()
DECLARE @line INT, @proc VARCHAR(MAX)
SELECT @line = ERROR_LINE(), @proc = ERROR_PROCEDURE()

SELECT @msg = ‘proc: ‘ + @proc + ‘; line: ‘ + CAST(@line as varchar) + ‘; msg: ‘ + @msg
SELECT @msg
END CATCH
GO

USE ExtremeAdviceSBMain
GO

–create following SP to handle response of target in initiatordatabase
–Create Initiator queue reader SP
CREATE PROC [OrderInitiatorQueueReader]
AS
SET NOCOUNT ON;
DECLARE @XML XML,
@MessageBody VARBINARY(MAX),
@MessageTypeName SYSNAME,
@ConversationHandle UNIQUEIDENTIFIER,
@Response XML

BEGIN TRY

WHILE (1 = 1)
BEGIN
BEGIN TRANSACTION
WAITFOR (
RECEIVE TOP(1)
@MessageTypeName = message_type_name,
@MessageBody = message_body,
@ConversationHandle = [conversation_handle]
FROM dbo.OrderInitiatorQueue
), TIMEOUT 60000

IF (@@ROWCOUNT = 0 AND @@TRANCOUNT>0)
BEGIN
ROLLBACK TRANSACTION
BREAK
END

IF @MessageTypeName = ‘http://schemas.microsoft.com/SQL/ServiceBroker/EndDialog’ BEGIN
END CONVERSATION @ConversationHandle;
END
COMMIT TRANSACTION
END
END TRY
BEGIN CATCH

IF @@TRANCOUNT > 0
ROLLBACK TRANSACTION
DECLARE @msg VARCHAR(MAX)
SELECT @msg = ERROR_MESSAGE()
DECLARE @line INT, @proc VARCHAR(MAX)
SELECT @line = ERROR_LINE(), @proc = ERROR_PROCEDURE()
SELECT @msg = ‘proc: ‘ + @proc + ‘; line: ‘ + CAST(@line as varchar) + ‘; msg: ‘ + @msg
END CATCH
GO

——-service broker call from trigger.
CREATE TRIGGER trg_OrderDetail_Ins
ON OrderDetail
AFTER INSERT
AS
BEGIN
SET NOCOUNT ON;

DECLARE @Data XML
SELECT @Data =
(
SELECT
‘OrderHistory’ AS ‘Header/@MessageType’,
OrderID AS ‘Header/@OrderID’,
ClientID AS ‘Header/@ClientID’,
ProjectID AS ‘Header/@ProjectID’
FROM
(SELECT * FROM inserted) AS T
FOR XML PATH(”), ROOT(‘OrderMessage’), TYPE
)

EXEC [SendOrderRequestMessage] @Data
END
GO
[/sourcecode]

Once you are ready with this structure, you are all set to go. Let us insert one record in OrderDetail table.

[sourcecode language=”sql”]
USE ExtremeAdviceSBMain
GO

–Testing SB by inserting one record in OrderDetail Table
–which will execute Trigger and trigger will activate SB
INSERT INTO OrderDetail(ClientID,ProjectID)
SELECT ‘TC01′,’NY Healthcare’
GO

–you will get one record which we have inserted above.
SELECT * FROM OrderDetail
GO

–you will get no record in OrderHistory table
–as we have not inserted duplicate record yet.
SELECT * FROM ExtremeAdviceSBReceiver.dbo.OrderHistory
GO
[/sourcecode]

Since we have not inserted any duplicate records yet, we won’t get any record in OrderHistory table. Let us inserting duplicate record in OrderDetail table.

[sourcecode language=”sql”]
–inserting same record again so SB will detect it as duplicate order
–that will be inserted in ORderHistory table
INSERT INTO OrderDetail(ClientID,ProjectID)
SELECT ‘TC01′,’NY Healthcare’
GO

–you will get one record in OrderHistory table
–as we have inserted duplicate record
SELECT * FROM ExtremeAdviceSBReceiver.dbo.OrderHistory
GO
[/sourcecode]

We, now, suppose to get record in OrderHistory table but unfortunately we won’t get it. There are two possibilities that either our initiator queue doesn’t have sent message to target or target have received the record but it has not processed it. Right???? Let us check it.

[sourcecode language=”sql”]
SELECT CAST(MESSAGE_BODY AS XML), * FROM ExtremeAdviceSBMain.DBO.OrderInitiatorQueue
SELECT CAST(MESSAGE_BODY AS XML), * FROM ExtremeAdviceSBReceiver.DBO.OrderTargetQueue
GO
[/sourcecode]

You can see that our “OrderTargetQueue” has record to process. Then question is why it has not processed?

Well, we have had Trigger on OrderDetail table which has activated our initiator queue and hence record reached to target queue but target queue has not been activated and hence it has not processed target message.

We can process message with following SP either manually or by sql server job as we have not activate it automatically.

[sourcecode language=”sql”]
USE ExtremeAdviceSBReceiver
GO

EXEC [OrderTargetQueueReader]
GO
[/sourcecode]

Now let us see whether record is processed or not.

You can see “OrderTargetQueue”has not record now as our message is processed and you can also see the entry in “OrderHistory” table also as we had one duplicate record.

Still “OrderInitiatorQueue” has record to process. You can see that it is just a blank message for end dialog with “OK” status which has sent back by target queue after processing messages.

We can run following SP to process end dialog in initiator queue.

[sourcecode language=”sql”]
USE ExtremeAdviceSBMain
GO

EXEC [OrderInitiatorQueueReader]
GO
[/sourcecode]

I will shortly come up with article which will run full service broker cycle by its own without manual interaction.

If you wish to refer my other Service Broker related article, have a look at following list:

Importance of Service Broker in SQL Server (Click Here)
Introduction of Service Broker in SQL Server (Click Here)
Enable Service Broker in SQL Server database (Click Here)
Small demonstration of Service broker for beginners (Click Here)
Find Service Broker Object like Contract, Message Type, Service Name, Queue Name in SQL Server (Click Here)
Find Service Broker Queue Count in SQL Server (Click Here)
Get Transmission queue row count in Service Broker (Click Here)
Purge target Transmission queue of Service Broker in SQL Server (Click Here)
Deal with size of Transmission Queue table sysxmitqueue in MSDB database (Click Here)
Service Broker implementation between two tables in one database (Click Here)
Service Broker Queue Activation and Thread in SQL Server (Click Here)

If you like this article, do like “Extreme-Advice” page in Facebook.

Reference: Ritesh Shah

http://Extreme-Advice.com

http://www.sqlhub.com

Note: Microsoft Books online is a default reference of all articles.

Service Broker implementation between two tables in one database

I have already provided small demonstration of how service broker works at “Small demonstration of Service broker for beginners” along with list of articles related to service broker from the concept of service broker to its implementation and definition of important part of Service Broker so I will not those concept here in this article, If you wish, you can have a look at those articles, here is the list:

Importance of Service Broker in SQL Server (Click Here)
Introduction of Service Broker in SQL Server (Click Here)
Enable Service Broker in SQL Server database (Click Here)
Small demonstration of Service broker for beginners (Click Here)
Find Service Broker Object like Contract, Message Type, Service Name, Queue Name in SQL Server (Click Here)
Find Service Broker Queue Count in SQL Server (Click Here)
Get Transmission queue row count in Service Broker (Click Here)
Purge target Transmission queue of Service Broker in SQL Server (Click Here)
Deal with size of Transmission Queue table sysxmitqueue in MSDB database (Click Here)

Let us now start implementing Service Broker for two tables in one database.

Let me explain the business logic which will be used in this article.

Sales people in Company “Extreme Trading” (ET) goes to client site and accept the order from client. Sales people may use iPad, iPhone or any other smart phone, tablet, laptop or other portable device to insert order of client.

There is a rule in company that any order shouldn’t have same client id and project id. If same client give order for same project, it should be added in original order. Original order should be edited. It shouldn’t insert new order id for same client, project combination.

Well, we can define composite primary key or put some validation or check constraint etc. but I don’t want to debate on this rule.

If any duplicate order comes, it should be accepted from the sales people but later on it should insert original order id along with new order id in one table so back office team can handle it and sales person could be free immediately without even waiting for validation gets completed.

Demonstrating this exercise, we will need one database along with two sample table before we start implementing actual service broker.

[sourcecode language=”sql”]
–create database.
CREATE DATABASE ExtremeAdviceSBDemo
GO

–making broker enable for database.
ALTER DATABASE ExtremeAdviceSBDemo SET ENABLE_BROKER
ALTER DATABASE ExtremeAdviceSBDemo SET TRUSTWORTHY ON;
ALTER AUTHORIZATION ON DATABASE::ExtremeAdviceSBDemo TO [sa];
GO

USE ExtremeAdviceSBDemo
GO

–two sample table for demonstration
CREATE TABLE OrderDetail
(
OrderID INT IDENTITY(1,1),
ClientID VARCHAR(10),
ProjectID VARCHAR(50),
OrderDate DATETIME DEFAULT GETDATE()
)
GO

CREATE TABLE OrderHistory
(
ID INT IDENTITY(1,1),
OrderID INT,
DuplicateWith INT,
CheckDate DATETIME DEFAULT GETDATE()
)
GO
[/sourcecode]

Now, let us start service broker code. I will not explain each block of code here, if you wish, you can refer my earlier articles given in first paragraph here.

[sourcecode language=”sql”]
–Create Message Type
CREATE MESSAGE TYPE [EXTREME://EX/Message/Order/Request] VALIDATION = WELL_FORMED_XML
CREATE MESSAGE TYPE [EXTREME://EX/Message/Order/Response] VALIDATION = WELL_FORMED_XML
GO

–Create Contract
CREATE CONTRACT [EXTREME://EX/Contract/Order]
(
[EXTREME://EX/Message/Order/Request] SENT BY INITIATOR,
[EXTREME://EX/Message/Order/Response] SENT BY TARGET
);
GO

–Create Initiator queue reader SP
CREATE PROC [OrderInitiatorQueueReader]
AS
SET NOCOUNT ON;
DECLARE @XML XML,
@MessageBody VARBINARY(MAX),
@MessageTypeName SYSNAME,
@ConversationHandle UNIQUEIDENTIFIER,
@Response XML

BEGIN TRY

IF (@@ROWCOUNT = 0 AND @@TRANCOUNT>0)
BEGIN
ROLLBACK TRANSACTION
BREAK
END

IF @MessageTypeName = ‘http://schemas.microsoft.com/SQL/ServiceBroker/EndDialog’ BEGIN
END CONVERSATION @ConversationHandle;
END
COMMIT TRANSACTION
END
END TRY
BEGIN CATCH

END CATCH
GO

–Create Initiator Queue
CREATE QUEUE OrderInitiatorQueue
WITH STATUS = ON,
ACTIVATION(
PROCEDURE_NAME = OrderInitiatorQueueReader,
MAX_QUEUE_READERS = 1,
EXECUTE AS OWNER
);
GO

— Create actual business logic SP
CREATE PROCEDURE [CheckOrderMessage]
(
@data XML
)
AS
BEGIN TRY

DECLARE @MessageType VARCHAR(50)
,@OrderID INT
,@ClientID VARCHAR(10)
,@ProjectID VARCHAR(50)

SELECT @MessageType = ISNULL(@MessageType,”)

IF @MessageType = ‘OrderHistory’ AND @OrderID IS NOT NULL BEGIN
DECLARE @OrderIDOld INT
,@ClientIDOld VARCHAR(10)
,@ProjectIDOld VARCHAR(50)

SELECT @ClientIDOld=ClientID, @ProjectIDOld=ProjectID, @OrderIDOld=OrderID
FROM OrderDetail
WHERE ClientID=@ClientID AND ProjectID=@ProjectID AND OrderID<>@OrderID

IF(@OrderIDOld IS NOT NULL)
BEGIN
INSERT INTO OrderHistory (OrderID,DuplicateWith)
SELECT @OrderIDOld,@OrderID
END
RETURN
END
END TRY

BEGIN CATCH
DECLARE @msg VARCHAR(MAX)
SELECT @msg = ERROR_MESSAGE()
END CATCH
RETURN
GO

–Create Target queue reader SP
CREATE PROC [OrderTargetQueueReader]
AS
SET NOCOUNT ON;

DECLARE @XML XML,
@MessageBody VARBINARY(MAX),
@MessageTypeName SYSNAME,
@ConversationHandle UNIQUEIDENTIFIER,
@Response XML

IF (@@ROWCOUNT = 0)
BEGIN
BREAK
END
SET @XML = CAST(@MessageBody AS XML);
IF @MessageTypeName = ‘EXTREME://EX/Message/Order/Request’
BEGIN
–PRINT ‘executing CheckOrderMessage @XML’
EXECUTE CheckOrderMessage @XML

–PRINT ‘sending response’
SELECT @xml = ‘OK’;
SEND ON CONVERSATION @ConversationHandle
MESSAGE TYPE [EXTREME://EX/Message/Order/Response](@xml);
–PRINT ‘ending cnversation’
END CONVERSATION @ConversationHandle;
END
END
END TRY
BEGIN CATCH
DECLARE @msg VARCHAR(MAX)
SELECT @msg = ERROR_MESSAGE()
DECLARE @line INT, @proc VARCHAR(MAX)
SELECT @line = ERROR_LINE(), @proc = ERROR_PROCEDURE()
SELECT @msg = ‘proc: ‘ + @proc + ‘; line: ‘ + CAST(@line as varchar) + ‘; msg: ‘ + @msg
SELECT @msg
END CATCH
GO

–Create Target Queue
CREATE QUEUE OrderTargetQueue
WITH STATUS = ON,
ACTIVATION(
PROCEDURE_NAME = OrderTargetQueueReader,
–You can change queue reader number based on your queue load
MAX_QUEUE_READERS = 1,
EXECUTE AS OWNER
);
GO

————–Create SP which will be called from app
–or trigger or by any other way
–and activate service broker
CREATE PROCEDURE [SendOrderRequestMessage]
(
@data AS XML
)
AS
SET XACT_ABORT OFF;
BEGIN TRY
BEGIN TRANSACTION

DECLARE @DialogHandle UNIQUEIDENTIFIER;

SEND ON CONVERSATION @DialogHandle
MESSAGE TYPE [EXTREME://EX/Message/Order/Request](@data);
–END CONVERSATION @DialogHandle
COMMIT ;
END TRY
BEGIN CATCH
ROLLBACK TRAN;
DECLARE @msg VARCHAR(MAX);
SELECT @msg = ERROR_MESSAGE();
PRINT @msg
END CATCH;
GO

–Create Initiator Service
CREATE SERVICE [EXTREME://EX/Service/Order/Initiator] ON QUEUE [OrderInitiatorQueue] ([EXTREME://EX/Contract/Order])
GO

–Create Target Service
CREATE SERVICE [EXTREME://EX/Service/Order/Target] ON QUEUE [OrderTargetQueue] ([EXTREME://EX/Contract/Order])
GO
[/sourcecode]

Now, we will define one trigger which will call SB to check whether order is duplicate or not every time we insert new record (not calling trigger for Update, you can do it if it is your business need)

[sourcecode language=”sql”]
——-service broker call from trigger.
CREATE TRIGGER trg_OrderDetail_Ins
ON OrderDetail
AFTER INSERT
AS
BEGIN
SET NOCOUNT ON;

EXEC [SendOrderRequestMessage] @Data
END
GO
[/sourcecode]

Now, we are ready with service broker architecture and ready to test whether SB is working or not.

[sourcecode language=”sql”]
–Testing SB by inserting one record in OrderDetail Table
–which will execute Trigger and trigger will activate SB
INSERT INTO OrderDetail(ClientID,ProjectID)
SELECT ‘TC01′,’NY Healthcare’
GO

–you will get one record which we have inserted above.
SELECT * FROM OrderDetail
GO

–you will get no record in OrderHistory table
–as we have not inserted duplicate record yet.
SELECT * FROM OrderHistory
GO

–inserting same record again so SB will detect it as duplicate order
–that will be inserted in ORderHistory table
INSERT INTO OrderDetail(ClientID,ProjectID)
SELECT ‘TC01′,’NY Healthcare’
GO

–you will get one record in OrderHistory table
–as we have inserted duplicate record
SELECT * FROM OrderHistory
GO
[/sourcecode]

I have not handled Error properly in CATCH block of Stored Procedure but just printed error message on screen because error handling is out of scope of this article, If you want to handle Error properly in Stored Procedure, have a look at my earlier article here.

If you like this article, do like “Extreme-Advice” page in Facebook.

Reference: Ritesh Shah

http://Extreme-Advice.com

http://www.sqlhub.com

Note: Microsoft Books online is a default reference of all articles.

Purge target Transmission queue of Service Broker in SQL Server

Last Sunday I have got very interesting question from one of my blog reader and before we discuss his question and solve it, let me give you some basic understanding regarding how message traverse between Initiator and Target Queue in very simple word by eliminating deep technicality.

When any message comes to service broker, message has to pass through various way including validation until it reaches to target queue and get processed.

Transmission Queue plays an important role in whole service broker architecture. Transmission Queue works as a “postman” between Initiator Queue and Target Queue.

Let me give you this understanding in simple words, without including deep technical explanation.

Suppose we have two server “S1” and “S2”. We have service broker implemented between these two servers. S1 is an initiator and S2 is a target. S1 sends message to process to S2 and S2 replies back to S1 via Transmission Queue.

Here is simple explanation in brief wording.

S1 send message to process to S2 via Transmission Queue and starts conversation dialog.
S2 receive message from S1’s Transmission Queue and acknowledge the same to S1 via S2’s Transmission Queue
Now, S2 process the message and again acknowledge the same to S1 via S2’s Transmission Queue
Finally message get processed and S2 send acknowledge of the same via Transmission Queue to S1 to finally close the conversation dialog
When S1 closes the conversation, it acknowledge the same to S2 and message gets deleted from the transmission queue of S2.

Please note that, our task get completes in first three steps whereas fourth & fifth steps are formality to close open conversation in S1 & S2.

I have written articles to watching the message count currently stays inside different queues.

Find Service Broker Queue Count in SQL Server (Click Here)
Get Transmission queue row count in Service Broker (Click Here)

One of the blog reader has implemented the functions I have given in both of the above articles and found that his initiator and target queue always having few hundreds message in peak business hours and become even zero many times but his transaction queue in target server (S2 in our example) having millions of message unprocessed. He wanted me to help him in dealing with that huge queue.

Obviously I don’t have access to his server so I have to guess after getting certain information from him. I have asked him to execute following query in his S2 server ‘s database where he has setup service broker and transmission queue showing millions of records.

[sourcecode language=”sql”]
SELECT
‘MessageNeedsToClose’ AS ActionToTake,
COUNT(*) AS RowsCount
FROM
sys.transmission_queue
WHERE
message_body IS NULL
AND is_end_of_dialog = 1
AND enqueue_time < getdate() – 7
UNION ALL
SELECT
‘MessageToKeep’ AS ActionToTake,
COUNT(*) AS RowsCount
FROM
sys.transmission_queue
WHERE
message_body IS NOT NULL
GO
[/sourcecode]

He sent me approx million+ records in “MessageNeedsToClose” and less then hundred count comes in “MessageToKeep”.

SELECT query before the UNION ALL clause checks where the row in transmission queue is having any message inside it or not. If Message_Body is NULL then there is no message at all. If “is_end_of_dialog” is 1 then that message is just an acknowledgment nothing else. So if there is no message to process in message_body and if message is just an acknowledgment, we can probably close it to fix the high number of queue one time, if message is already closed from initiator side.

Reader has already told me that transmission queue on initiator side (in server S1) always stays below 1000 and become zero also so there is no chance that the million message we have seen in S2 is still there open in S1.

Since I didn’t have access to his server to investigate further and the messages we have in target transmission queue is not a real business process, we can close that dialog. If I would have access to server, I would run profiler for broker in S1 as well as in S2 to see what is happening with that big transmission queue but the reader was already convinced and wanted to settled down by closing the conversation of dialog.

I have written one customized Stored procedure for him to create on Server S2 in the database where he has Service Broker setup.

[sourcecode language=”sql”]
CREATE PROCEDURE [CleanTransmissionQueueByEndingDialog]
AS
SET NOCOUNT ON
BEGIN
BEGIN TRY
DECLARE @ConvHandle UNIQUEIDENTIFIER

DECLARE conv CURSOR FOR

SELECT
S2TransQueue.conversation_handle
FROM
sys.conversation_endpoints AS S2ConvEnd WITH(NOLOCK)
INNER JOIN
sys.transmission_queue S2TransQueue WITH(NOLOCK)
ON
S2TransQueue.conversation_handle = S2ConvEnd.conversation_handle
AND S2TransQueue.message_body is null
AND S2TransQueue.is_end_of_dialog = 1
AND S2TransQueue.enqueue_time < getdate() – 7

–I HIGHLY recomment uncomment the following WHERE clause to check
–where same message is alive in initiator end or not
–if it is alive, we shouldn’t close that message.

–WHERE NOT EXISTS(
— SELECT 1
— –S1 is a Linked Server, you have to replace it with your linked server of Initiator
— –"DatabaseName" should be replace by your database name where you have setup
— –Service Broker in Initiator Server.
— FROM S1.DatabaseName.sys.conversation_endpoints S1ConvEnd with(nolock)
— WHERE S1ConvEnd.conversation_id = S2ConvEnd.conversation_id
–)

OPEN conv
FETCH NEXT FROM conv INTO @ConvHandle

WHILE @@FETCH_STATUS = 0 Begin
END CONVERSATION @ConvHandle WITH cleanup
FETCH NEXT FROM conv into @ConvHandle
PRINT @ConvHandle
END

CLOSE conv
DEALLOCATE conv

END TRY

BEGIN CATCH
PRINT ERROR_MESSAGE()
END CATCH
END
GO
[/sourcecode]

Please note that I have investigated this issue without accessing live server of blog reader. Whatever suggestions I have given here is going to affect your live production environment if you are executing this script in production environment so please give a second thought and do it at your own risk.

I have written some other articles related to service broker, if you are directly landed to this article and new to Service broker, have a look at following articles which covers Service Broker concept from scratch.

Importance of Service Broker in SQL Server (Click Here)
Introduction of Service Broker in SQL Server (Click Here)
Enable Service Broker in SQL Server database (Click Here)
Small demonstration of Service broker for beginners (Click Here)
Find Service Broker Object like Contract, Message Type, Service Name, Queue Name in SQL Server (Click Here)
Find Service Broker Queue Count in SQL Server (Click Here)
Get Transmission queue row count in Service Broker (Click Here)

If you like this article, do like “Extreme-Advice” page in Facebook.

Reference: Ritesh Shah

http://Extreme-Advice.com

http://www.sqlhub.com

Note: Microsoft Books online is a default reference of all articles.

Small demonstration of Service broker for beginners

If you are new to Service Broker and want to know what service broker is and where can we use service broker, you can have a look at my two earlier articles.

Importance of Service Broker in SQL Server (Click Here)

Introduction of Service Broker in SQL Server (Click Here)

If your database is not already enabled for Service Broker, have a look at following link to know how to enable Service Broker for database in SQL Server.

Enable Service Broker in SQL Server database (Click Here)

Once you are ready with basic understanding of Service broker, we can, now, focus on developing architecture for service broker. This article will show you very basic architecture of service broker without much complexity so that even beginners can understand it easily, later on I will come up with some exciting and complex architecture of Service Broker.

Creating sample database and enable service broker for it.

[sourcecode language=”sql”]
USE MASTER
GO

CREATE DATABASE ExtremeAdviceSB
GO

ALTER DATABASE ExtremeAdviceSB SET Enable_Broker WITH ROLLBACK IMMEDIATE
GO
[/sourcecode]

Now, creating two different message type. One for request message for initiator service and another one for response message for target service.

Note: If you are not aware with “Message Type” and other service broker related terms, please click here.

[sourcecode language=”sql”]
USE ExtremeAdviceSB
GO

CREATE MESSAGE TYPE [http://Extreme-Advice.com/SBDemo01/RequestMessage]
VALIDATION = WELL_FORMED_XML
GO

CREATE MESSAGE TYPE [http://Extreme-Advice.com/SBDemo01/ResponseMessage]
VALIDATION = WELL_FORMED_XML
GO
[/sourcecode]

Now, we will create one contract which will define which message type will be used from initiator as well as from target.

[sourcecode language=”sql”]
CREATE CONTRACT [http://Extreme-Advice.com/SBDemo01/ExtremeAdviceContractDemo]
(
[http://Extreme-Advice.com/SBDemo01/RequestMessage] SENT BY INITIATOR,
[http://Extreme-Advice.com/SBDemo01/ResponseMessage] SENT BY TARGET
)
GO
[/sourcecode]

Once, you are ready with Contract, it is a time to define two queue 1.) Initiator Queue 2.) Target Queue. Which will be used by core logic or service program. Initiator queue will generate message/request which will be sent to target queue after validation. Target queue will process message/request and generate response message and send to initiator queue.

[sourcecode language=”sql”]
CREATE QUEUE SBDemoInitiatorQueue
WITH STATUS = ON
GO

CREATE QUEUE SBDemoTargetQueue
WITH STATUS = ON
GO
[/sourcecode]

After having both the queue, need to define service which will work for the same contract we have created above in our example.

[sourcecode language=”sql”]
CREATE SERVICE SBDemoInitiatorService
ON QUEUE SBDemoInitiatorQueue
(
[http://Extreme-Advice.com/SBDemo01/ExtremeAdviceContractDemo]
)
GO

CREATE SERVICE SBDemoTargetService
ON QUEUE SBDemoTargetQueue
(
[http://Extreme-Advice.com/SBDemo01/ExtremeAdviceContractDemo]
)
GO
[/sourcecode]

Well now we are ready with basic architecture of service broker for our first demonstration for beginners. Here is the screen capture from my SSMS which shows every object I have created above. Have a look:

We will generate two message from initiator and send it to target with “BEGIN DIALOG CONVERSATION” command.

[sourcecode language=”sql”]
–Message 1
BEGIN TRY
BEGIN TRANSACTION;

DECLARE @UniId UNIQUEIDENTIFIER
DECLARE @SBMessage NVARCHAR(MAX);

BEGIN DIALOG CONVERSATION @UniId
FROM SERVICE SBDemoInitiatorService
TO SERVICE ‘SBDemoTargetService’
ON CONTRACT [http://Extreme-Advice.com/SBDemo01/ExtremeAdviceContractDemo]
WITH ENCRYPTION = OFF;
SET @SBMessage =
‘<SBRequest>
Message 1: Extreme-Advice.com on Service Broker
</SBRequest>’;

SEND ON CONVERSATION @UniId MESSAGE TYPE
[http://Extreme-Advice.com/SBDemo01/RequestMessage]
(
@SBMessage
);
COMMIT;
END TRY
BEGIN CATCH
ROLLBACK TRANSACTION
END CATCH
GO

–Message 2
BEGIN TRY
BEGIN TRANSACTION;

DECLARE @UniId UNIQUEIDENTIFIER
DECLARE @SBMessage NVARCHAR(MAX);

BEGIN DIALOG CONVERSATION @UniId
FROM SERVICE SBDemoInitiatorService
TO SERVICE ‘SBDemoTargetService’
ON CONTRACT [http://Extreme-Advice.com/SBDemo01/ExtremeAdviceContractDemo]
WITH ENCRYPTION = OFF;
SET @SBMessage =
‘<SBRequest>
Message 2: Extreme-Advice.com on Service Broker
</SBRequest>’;

SEND ON CONVERSATION @UniId MESSAGE TYPE
[http://Extreme-Advice.com/SBDemo01/RequestMessage]
(
@SBMessage
);

COMMIT;
END TRY
BEGIN CATCH
ROLLBACK TRANSACTION
END CATCH
GO
[/sourcecode]

Since we have generated two message from TSQL given above, we can confirm the same with “SBDemoTargetQueue” hidden table of target queue.

[sourcecode language=”sql”]
SELECT CAST(message_body as XML) AS Message, * FROM SBDemoTargetQueue
GO
[/sourcecode]

Here is the screen capture of above SELECT statement:

Now, we have to message received in target queue which we have seen above. Now, question is, how to process it?

Well, we have “RECEIVE” command to process the record by reading “SBDemoTargetQueue” hidden table. Here is the code which will process one record from target queue table. Since we have two records in target queue, we have to execute following TSQL two times to get both record processed.

[sourcecode language=”sql”]
DECLARE @ConvGroupID UNIQUEIDENTIFIER
DECLARE @ConvHandleID UNIQUEIDENTIFIER
DECLARE @messagetypename NVARCHAR(256)
DECLARE @messagebody XML;
BEGIN TRY
BEGIN TRANSACTION;

RECEIVE TOP (1)
@ConvGroupID = conversation_group_id,
@ConvHandleID = conversation_handle,
@messagetypename = message_type_name,
@messagebody = CAST(message_body AS XML)
FROM SBDemoTargetQueue

IF (@@ROWCOUNT > 0)
BEGIN
PRINT ‘MessageType: ‘ + @messagetypename
PRINT ‘MessageXML: ‘ + CAST(@messagebody AS NVARCHAR(MAX))
END
COMMIT
END TRY
BEGIN CATCH
ROLLBACK TRANSACTION
END CATCH
GO
[/sourcecode]

Once you are done with both the message from target queue, you can confirm that there is nothing left in your target queue’s hidden table.

[sourcecode language=”sql”]
SELECT CAST(message_body as XML) AS Message, * FROM SBDemoTargetQueue
GO
[/sourcecode]

If you like this article, do like “Extreme-Advice” page in Facebook.

Reference: Ritesh Shah

http://Extreme-Advice.com

http://www.sqlhub.com

Note: Microsoft Books online is a default reference of all articles.