Using SQL Azure with ELMAH

If you don’t know what ELMAH is, stop right now and go and read about it.

ELMAH (Error Logging Modules and Handlers) is an application-wide error logging facility that is completely pluggable. It can be dynamically added to a running ASP.NET web application, or even all ASP.NET web applications on a machine, without any need for re-compilation or re-deployment.

Then go and read Scott “TheHa” Hanselman’s post on it.

There is a Nuget package for it as well, to make things really super easy.

In fact, running Nuget, setting up SQL Azure and tweaking some config settings took me all of 20 minutes. No freaking kidding. 

Now remember that this is being installed on an MVC site, so don’t let that put you off. Here we go:

Step One: Install from Nuget (making sure you have the latest build of Nuget in the process)

Step Two: Setup SQL Azure

Step Three configure web.config

 

And done Smile

 

So, lets go back and look at the details.

In step two, this is the SQL Azure script that the Migrate Assist wizard spat out:

--~Changing index [dbo].[ELMAH_Error].PK_ELMAH_Error to a clustered index.  You may want to pick a different index to cluster on.
SET ANSI_NULLS ON
SET QUOTED_IDENTIFIER ON
IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[ELMAH_Error]') AND type in (N'U'))
BEGIN
CREATE TABLE [dbo].[ELMAH_Error](
	[ErrorId] [uniqueidentifier] NOT NULL,
	[Application] [nvarchar](60) NOT NULL,
	[Host] [nvarchar](50) NOT NULL,
	[Type] [nvarchar](100) NOT NULL,
	[Source] [nvarchar](60) NOT NULL,
	[Message] [nvarchar](500) NOT NULL,
	[User] [nvarchar](50) NOT NULL,
	[StatusCode] [int] NOT NULL,
	[TimeUtc] [datetime] NOT NULL,
	[Sequence] [int] IDENTITY(1,1) NOT NULL,
	[AllXml] [nvarchar](max) NOT NULL,
 CONSTRAINT [PK_ELMAH_Error] PRIMARY KEY CLUSTERED 
(
	[ErrorId] ASC
)WITH (STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF)
)
END

IF NOT EXISTS (SELECT * FROM sys.indexes WHERE object_id = OBJECT_ID(N'[dbo].[ELMAH_Error]') AND name = N'IX_ELMAH_Error_App_Time_Seq')
CREATE NONCLUSTERED INDEX [IX_ELMAH_Error_App_Time_Seq] ON [dbo].[ELMAH_Error] 
(
	[Application] ASC,
	[TimeUtc] DESC,
	[Sequence] DESC
)WITH (STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF)
GO
IF NOT EXISTS (SELECT * FROM dbo.sysobjects WHERE id = OBJECT_ID(N'[DF_ELMAH_Error_ErrorId]') AND type = 'D')
BEGIN
ALTER TABLE [dbo].[ELMAH_Error] ADD  CONSTRAINT [DF_ELMAH_Error_ErrorId]  DEFAULT (newid()) FOR [ErrorId]
END

GO
SET ANSI_NULLS ON
SET QUOTED_IDENTIFIER ON
IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[ELMAH_GetErrorsXml]') AND type in (N'P', N'PC'))
BEGIN
EXEC dbo.sp_executesql @statement = N'
CREATE PROCEDURE [dbo].[ELMAH_GetErrorsXml]
(
    @Application NVARCHAR(60),
    @PageIndex INT = 0,
    @PageSize INT = 15,
    @TotalCount INT OUTPUT
)
AS 

    SET NOCOUNT ON

    DECLARE @FirstTimeUTC DATETIME
    DECLARE @FirstSequence INT
    DECLARE @StartRow INT
    DECLARE @StartRowIndex INT

    SELECT 
        @TotalCount = COUNT(1) 
    FROM 
        [ELMAH_Error]
    WHERE 
        [Application] = @Application

    -- Get the ID of the first error for the requested page

    SET @StartRowIndex = @PageIndex * @PageSize + 1

    IF @StartRowIndex <= @TotalCount
    BEGIN

        SET ROWCOUNT @StartRowIndex

        SELECT  
            @FirstTimeUTC = [TimeUtc],
            @FirstSequence = [Sequence]
        FROM 
            [ELMAH_Error]
        WHERE   
            [Application] = @Application
        ORDER BY 
            [TimeUtc] DESC, 
            [Sequence] DESC

    END
    ELSE
    BEGIN

        SET @PageSize = 0

    END

    -- Now set the row count to the requested page size and get
    -- all records below it for the pertaining application.

    SET ROWCOUNT @PageSize

    SELECT 
        errorId     = [ErrorId], 
        application = [Application],
        host        = [Host], 
        type        = [Type],
        source      = [Source],
        message     = [Message],
        [user]      = [User],
        statusCode  = [StatusCode], 
        time        = CONVERT(VARCHAR(50), [TimeUtc], 126) + ''Z''
    FROM 
        [ELMAH_Error] error
    WHERE
        [Application] = @Application
    AND
        [TimeUtc] <= @FirstTimeUTC
    AND 
        [Sequence] <= @FirstSequence
    ORDER BY
        [TimeUtc] DESC, 
        [Sequence] DESC
    FOR
        XML AUTO

' 
END
GO
SET ANSI_NULLS ON
SET QUOTED_IDENTIFIER ON
IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[ELMAH_GetErrorXml]') AND type in (N'P', N'PC'))
BEGIN
EXEC dbo.sp_executesql @statement = N'
CREATE PROCEDURE [dbo].[ELMAH_GetErrorXml]
(
    @Application NVARCHAR(60),
    @ErrorId UNIQUEIDENTIFIER
)
AS

    SET NOCOUNT ON

    SELECT 
        [AllXml]
    FROM 
        [ELMAH_Error]
    WHERE
        [ErrorId] = @ErrorId
    AND
        [Application] = @Application

' 
END
GO
SET ANSI_NULLS ON
SET QUOTED_IDENTIFIER ON
IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[ELMAH_LogError]') AND type in (N'P', N'PC'))
BEGIN
EXEC dbo.sp_executesql @statement = N'
CREATE PROCEDURE [dbo].[ELMAH_LogError]
(
    @ErrorId UNIQUEIDENTIFIER,
    @Application NVARCHAR(60),
    @Host NVARCHAR(30),
    @Type NVARCHAR(100),
    @Source NVARCHAR(60),
    @Message NVARCHAR(500),
    @User NVARCHAR(50),
    @AllXml NVARCHAR(MAX),
    @StatusCode INT,
    @TimeUtc DATETIME
)
AS

    SET NOCOUNT ON

    INSERT
    INTO
        [ELMAH_Error]
        (
            [ErrorId],
            [Application],
            [Host],
            [Type],
            [Source],
            [Message],
            [User],
            [AllXml],
            [StatusCode],
            [TimeUtc]
        )
    VALUES
        (
            @ErrorId,
            @Application,
            @Host,
            @Type,
            @Source,
            @Message,
            @User,
            @AllXml,
            @StatusCode,
            @TimeUtc
        )

' 
END
GO

Log in to SQL Management Studio and run that script against your chosen db and you’re good to go.

 

In step 3, there are 2 main things you want to do.

The first is obviously setting up ELMAH to talk to the db. We do it like so.

<elmah>
    <errorLog type="Elmah.SqlErrorLog, Elmah" connectionStringName="ConnectionStringhere" />
    <security allowRemoteAccess="yes" />
  </elmah>

And the second is securing the actual elmah.axd page.

  <location path="elmah.axd">
    <system.web>
      <authorization>
        <deny users="?"/>
        <allow roles="Administrator"/>
      </authorization>
    </system.web>
  </location>

And we’re done. Easiest thing I’ve ever done. Smile