服务代理消息流程订单

Question

我读到的每个地方都说服务代理处理的消息按照它们到达的顺序进行处理，但是如果你创建一个表，消息类型，合同，服务等，并且在激活时有一个等待2秒的存储过程并插入将msg放入一个表中，将最大队列读取器设置为5或10，并发送20条奇怪的消息，即使我将它们插入队列并查看内容queue我可以看到消息都是正确的顺序。

是因为延迟等待最近的秒，每个线程有不同的亚秒时间，然后争取一个锁或什么？

我有延迟的原因是模拟连接等延迟

谢谢

演示代码：

--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

要保持相同的顺序，必须在同一个对话中发送消息。 如果您为每条消息生成一个对话（如大多数示例所示），则无法保证它们的交付顺序。

每次使用BEGIN DIALOG语句时，您都会创建一个新对话。 只做一次，然后在同一个对话中发送所有消息，你就会得到你期望的序列。