SharePoint (ASP.NET) Application works fine until morning, only an IISRESET fixes problem

Question

A colleague has developed a SharePoint web-part application (which was developed in VS2005), and deployed on MOSS 2007. We use an .ASCX file for deployment.

This application works fine all day, but something happens overnight whereby we need to do an IISRESET every-morning before it starts working again. (It is basically driving us nuts!)

The error we get is:

the type specified in the TypeName property of ObjectDataSource 'ObjectDataSource2' could not be found

The relevant 'ObjectDataSource2' in the ascx file has this code:

<asp:ObjectDataSource ID="ObjectDataSource2" runat="server" InsertMethod="Insert"
OldValuesParameterFormatString="original_{0}" SelectMethod="GetDataByEnquiryType"
TypeName="crmDatasetTableAdapters.Lookup_tableTableAdapter">
<InsertParameters>
    <asp:Parameter Name="Domain" Type="String" />
    <asp:Parameter Name="code" Type="String" />
    <asp:Parameter Name="meaning" Type="String" />
    <asp:Parameter Name="enabled" Type="Int32" />
    <asp:Parameter Name="Link" Type="String" />
</InsertParameters>
</asp:ObjectDataSource>

The dropdownlist using the above datasource is:

<asp:DropDownList ID="ddlEnquiryType" runat="server" AutoPostBack="True" DataSourceID="ObjectDataSource2"
DataTextField="meaning" DataValueField="meaning" Width="256px">

The TypeName entry is referring to a dataset that was created (.xsd file). We have a web.config connection string that looks like:

<add name="crmConnectionString" connectionString="Data Source=myservername;Initial Catalog=CRM;User Id=xyz123;Password=***************;Integrated Security=False;Connect Timeout=30;" providerName="System.Data.SqlClient" />

As I mentioned, this application works fine in VS2005, VS2008, and also when within SharePoint. - Until overnight, and the sharePoint server 'loses' whatever it needs regarding 'ObjectDataSource2'.

Can anyone shed light on this puzzle? If you need more information, then let me know.

Thanks in advance!

Answer 1

We saw similar behavior a few years ago. It had to do with how the .NET runtime loads assemblies after it gets unloaded from memory (after a period of non-use, which sounds like what could happen with your application). This can be related to not using the fully qualified name of the assembly. If you have a SafeCode entry for a business layer DLL you are using, make sure it's fully qualified.

DLLName, Version=1.0.3300.0, Culture=neutral, PublicKeyToken=b77a5c561934e089

as opposed to

DLLName

Also verify references in ASCX are fully qualified.

Interested if that's the issue. Took us FOREVER to resolve that one. In the interim to work around the problem we created a command line application to ping the server every 5 minutes so users did not see an error in the morning in case what is outlined above does not resolve.

Answer 2

Can you check the 12 hive logs, EventViewer to see any issues pertaining to the web application.

if it is sure that this is caused by the new application i suggest you write a custom log to find if there are any issues

Answer 3

Are you seeing a persistent error where IIS shuts down the web app because of the persistent error, or just the single error and it doesn't work again?

I'd almost wonder if there's a nightly backup (or some other operation) on that data source that's interrupting your connection and it's simply failing after the connection gets interrupted.

Is the error time fairly consistent in your logs from night to night?