服務代理消息流程訂單

Question

我讀到的每個地方都說服務代理處理的消息按照它們到達的順序進行處理，但是如果你創建一個表，消息類型，合同，服務等，並且在激活時有一個等待2秒的存儲過程並插入將msg放入一個表中，將最大隊列讀取器設置為5或10，並發送20條奇怪的消息，即使我將它們插入隊列並查看內容queue我可以看到消息都是正確的順序。

是因為延遲等待最近的秒，每個線程有不同的亞秒時間，然后爭取一個鎖或什么？

我有延遲的原因是模擬連接等延遲

謝謝

演示代碼：

--create the table and service broker

CREATE TABLE test
(
id int identity(1,1),
contents varchar(100)
)

CREATE MESSAGE TYPE test

CREATE CONTRACT mycontract
(
test sent by initiator
)
GO
CREATE PROCEDURE dostuff
AS
BEGIN
    DECLARE @msg varchar(100);
    RECEIVE TOP (1) @msg = message_body FROM myQueue
    IF @msg IS NOT NULL
    BEGIN
        WAITFOR DELAY '00:00:02'
        INSERT INTO test(contents)values(@msg)
    END
END
GO
ALTER QUEUE myQueue
    WITH STATUS = ON,
    ACTIVATION (
        STATUS = ON,
        PROCEDURE_NAME = dostuff,
        MAX_QUEUE_READERS = 10,
        EXECUTE AS SELF
    )

create service senderService
on queue myQueue
(
mycontract
)

create service receiverService
on queue myQueue
(
mycontract
)
GO

--**********************************************************

--now insert lots of messages to the queue

DECLARE @dialog_handle uniqueidentifier

    BEGIN DIALOG @dialog_handle
        FROM SERVICE senderService
        TO SERVICE 'receiverService'
        ON CONTRACT mycontract;

    SEND
        ON CONVERSATION @dialog_handle
        MESSAGE TYPE test
        ('<test>1</test>');

    BEGIN DIALOG @dialog_handle
        FROM SERVICE senderService
        TO SERVICE 'receiverService'
        ON CONTRACT mycontract;

    SEND
        ON CONVERSATION @dialog_handle
        MESSAGE TYPE test
        ('<test>2</test>')

    BEGIN DIALOG @dialog_handle
        FROM SERVICE senderService
        TO SERVICE 'receiverService'
        ON CONTRACT mycontract;

    SEND
        ON CONVERSATION @dialog_handle
        MESSAGE TYPE test
        ('<test>3</test>')

BEGIN DIALOG @dialog_handle
        FROM SERVICE senderService
        TO SERVICE 'receiverService'
        ON CONTRACT mycontract;

    SEND
        ON CONVERSATION @dialog_handle
        MESSAGE TYPE test
        ('<test>4</test>')

BEGIN DIALOG @dialog_handle
        FROM SERVICE senderService
        TO SERVICE 'receiverService'
        ON CONTRACT mycontract;

    SEND
        ON CONVERSATION @dialog_handle
        MESSAGE TYPE test
        ('<test>5</test>')

BEGIN DIALOG @dialog_handle
        FROM SERVICE senderService
        TO SERVICE 'receiverService'
        ON CONTRACT mycontract;

    SEND
        ON CONVERSATION @dialog_handle
        MESSAGE TYPE test
        ('<test>6</test>')

BEGIN DIALOG @dialog_handle
        FROM SERVICE senderService
        TO SERVICE 'receiverService'
        ON CONTRACT mycontract;

    SEND
        ON CONVERSATION @dialog_handle
        MESSAGE TYPE test
        ('<test>7</test>')

Answer 1

要保持相同的順序，必須在同一個對話中發送消息。 如果您為每條消息生成一個對話（如大多數示例所示），則無法保證它們的交付順序。

每次使用BEGIN DIALOG語句時，您都會創建一個新對話。 只做一次，然后在同一個對話中發送所有消息，你就會得到你期望的序列。