sql-server - SQL Server 过程超时

Question

从生产站点上的 ASP.NET 前端环境调用此存储过程时，我遇到了中间超时。它返回以下 sql 异常:

Exception Details: System.Data.SqlClient.SqlException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.

有趣的是，当在服务器上或使用 Management Studio 从远程 PC 上执行此过程时，它会在 6 秒内执行。但是，有时从 ASP.NET 应用程序执行时会超时？这个查询可以改进吗？或者这个问题与其他问题有关？有谁可以帮忙吗？我读过一些关于增加超时和在 web.config 中的连接字符串上启用池化的线程，但还没有尝试过。

 ALTER PROCEDURE [dbo].[Report_Activity]
    (
        @StartDate      DATETIME
    ,   @EndDate        DATETIME
    ,   @TotalActions INT OUTPUT
    )

    AS
    BEGIN 

        SELECT      @TotalActions = COUNT(EventHistoryId)
        FROM        dbo.SessionEventHistory
        WHERE       DateCreated BETWEEN @StartDate AND @EndDate

        SELECT      EventDescription, COUNT(EventHistoryId) AS EventCount           
        FROM        dbo.SessionEventHistory
        WHERE       DateCreated BETWEEN @StartDate AND @EndDate
        GROUP BY    EventDescription
        ORDER BY    EventDescription

SQL 架构:

CREATE TABLE [dbo].[SessionEventHistory](
    [EventHistoryID] [int] IDENTITY(1,1) NOT NULL,
    [SessionHistoryID] [int] NOT NULL,
    [CategoryID] [int] NULL,
    [UserName] [nvarchar](50) NULL,
    [IPAddress] [nvarchar](20) NOT NULL,
    [EventDescription] [nvarchar](1000) NOT NULL,
    [EventData] [varbinary](max) NULL,
    [DateCreated] [datetime] NOT NULL,
 CONSTRAINT [PK_UserEventHistory] PRIMARY KEY CLUSTERED 
(
    [EventHistoryID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

GO

ALTER TABLE [dbo].[SessionEventHistory] ADD  CONSTRAINT [DF_UserEventHistory_DateCreated]  DEFAULT (getdate()) FOR [DateCreated]
GO

表有 3 个索引:

/****** Object:  Index [IX_SessionEventHistory_SessionHistoryId_CategoryId]    Script Date: 07/04/2012 10:47:06 ******/
CREATE NONCLUSTERED INDEX [IX_SessionEventHistory_SessionHistoryId_CategoryId] ON [dbo].[SessionEventHistory] 
(
    [SessionHistoryID] ASC,
    [CategoryID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
GO


/****** Object:  Index [IX_SessionEventHistory_UserName_DateCreated]    Script Date: 07/04/2012 10:47:09 ******/
CREATE NONCLUSTERED INDEX [IX_SessionEventHistory_UserName_DateCreated] ON [dbo].[SessionEventHistory] 
(
    [UserName] ASC,
    [DateCreated] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
GO


/****** Object:  Index [PK_UserEventHistory]    Script Date: 07/04/2012 10:47:14 ******/
ALTER TABLE [dbo].[SessionEventHistory] ADD  CONSTRAINT [PK_UserEventHistory] PRIMARY KEY CLUSTERED 
(
    [EventHistoryID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
GO

编辑

我添加了以下索引，看起来还好吗？

CREATE NONCLUSTERED INDEX [IX_SessionEventHistory_DateCreated] ON [dbo].[SessionEventHistory] 
(
    [DateCreated] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
GO

Answer 1

查看 ASP.Net 应用程序和 SSMS session 的 sys.dm_exec_sessions。我大胆猜测您的 SET 设置中至少有一个是不同的。这可能会导致不同的计划(最终这归因于参数嗅探)，并且应用程序端通常会因此而变得更糟。

请参阅这些其他问题以了解更多详细信息:

Stored procedure slow when called from web, fast from Management Studio

Procedure times out from ADO.NET but not in SSMS

Query times out when executed from web, but super-fast when executed from SSMS

ADO .NET vs. SQL Server Management Studio - ADO performs worse

另请阅读this great article by Erland Sommarskog .