Blazor page works from Visual Studio but not from IIS

[mnbob70]

.NET 9 Blazor static SSR application.

I am completely stumped by an issue I am experiencing. I have a page that retrieves two data items asynchronously. One is a simple count (int) and the other is an item list for display in a table. Note that retrieving the item list works correctly.

No matter what I do, the count value is 0 when the application runs hosted in IIS while it is 17 when running in Visual Studio. I originally had two variables and set both with await statements in OnInitializedAsync. Since then I have tried all kinds of alternatives including setting the count value synchronously. Currently I have a separate nullable myData object to hold both the count and the item list and check that value to see if it is null. I have also completely commented out the retrieval of the item list so I'm only dealing with the count and still the value is treated as 0 in IIS. This issue occurs with stream rendering on or off (currently on as shown below).

Here is the output in Visual Studio:

Here is the output in IIS:

Code:
private string Title { get; set; } = "App Monitor";
//private int? failedEmailCount;
//private AppMonitorRow[]? items;
private AppMonitorData? myData;

protected override async Task OnInitializedAsync()
{
	//myData = await GetAppMonitorData();
	var count = await GetAutoReportMonitorCountAsync();
	myData = new AppMonitorData()
	{
		FailedEmailCount = count,
		Items = []
	};
}

public int GetAutoReportMonitorCount()
{
	using SqlConnection con = new SqlConnection(_logsContext.Database.GetConnectionString());
	using SqlCommand cmd = new SqlCommand("AutoReportMonitorCount", con);
	cmd.CommandType = CommandType.StoredProcedure;
	var param = cmd.Parameters.Add("@RowCount", SqlDbType.Int);
	param.Direction = ParameterDirection.Output;
	con.Open();
	cmd.ExecuteNonQuery();
	return (int)param.Value;
}

public async Task<int> GetAutoReportMonitorCountAsync()
{
	using SqlConnection con = new SqlConnection(_logsContext.Database.GetConnectionString());
	using SqlCommand cmd = new SqlCommand("AutoReportMonitorCount", con);
	cmd.CommandType = CommandType.StoredProcedure;
	var param = cmd.Parameters.Add("@RowCount", SqlDbType.Int);
	param.Direction = ParameterDirection.Output;
	await con.OpenAsync();
	await cmd.ExecuteNonQueryAsync();
	return (int)param.Value;
}

Here is the relevant part of the html.
At the statement if (myData.FailedEmailCount > 0) the count is 0 because "(myData is null)" flashes in IIS as it's removed when myData ends up with a value.

@page "/appmonitor"
@attribute [StreamRendering]
@inject Data.LogsContext _logsContext
<PageTitle>@Title</PageTitle>
<PageScript Src="./Components/Pages/AppMonitor.razor.js?appmonitor" />

<div class="d-flex align-items-center"><h2>@Title</h2><div class="timestamp">@DateTime.Now.ToString()</div></div>
@* @if (failedEmailCount is null && items is null) *@
@if (myData is null)
{
	<div class="table-responsive-md tableFixHead">
		<table id="jurisdictionStats" class="table table-sm">
			<thead class="table-light">
				<tr>
					<th>Status</th>
					<th>Application</th>
					<th class="text-center">ID</th>
					<th class="text-center">Type</th>
					<th>Process</th>
					<th class="text-center"><span class="bi bi-info-circle-fill" data-bs-toggle="popover" data-bs-trigger="hover focus" data-bs-html="true" data-bs-content="<p>A non-Recurring task is expected to log a RecordsAffected value &gt; 0 in order to have completed successfully.</p><p>A Recurring task repeats and completes regardless of the logged value of RecordsAffected.</p>"></span> Recurring?</th>
					<th class="text-center">Server</th>
					<th class="text-center">Last Start</th>
					<th class="text-center">Last Stop</th>
					<th class="text-center">Duration</th>
					<th class="text-center">Recs</th>
					<th class="text-center">Next Start</th>
					<th class="text-center">Next Stop</th>
				</tr>
			</thead>
			<tbody>
				<tr><td colspan="13">No applications were found. (myData is null)</td></tr>
			</tbody>
		</table>
	</div>
}
else
{
 	if (myData.FailedEmailCount > 0)
	{
 		<div class="alert alert-warning" role="alert">
			<strong>There are @myData.FailedEmailCount failed report emails!</strong> Check the <a href="https://dmg.indecomm.net/reportmonitor/" target="_blank">Report Monitor</a> and FilingData.dbo.tbl_WebReportRequests.
		</div>
	}
	<div class="table-responsive-md tableFixHead">
		<table id="jurisdictionStats" class="table table-sm">

[mnbob70]

If I hard code a value for the count then it works in IIS, but any query (async or not) results in a count value of 0 on IIS. I have separately confirmed that the assigned app identity in IIS has permission to execute the stored procedure used. Besides, there is no error occuring becauase of any type of database issue.

In the following code block I have also tried to retrieve and set the value synchronously. It works in IIS with 17 hard coded as shown (and also async) but it does not work (count = 0) if I assign the value of count instead. WTF?

@code {
	private string Title { get; set; } = "App Monitor";
	private AppMonitorData? myData;

	protected override void OnInitialized()
	{
		var count = GetAutoReportMonitorCount();
		myData = new AppMonitorData()
		{
			FailedEmailCount = 17,
		};
	}

	protected override async Task OnInitializedAsync()
	{
		var items = await GetAppMonitorItems();
		if (myData is null)
		{
			myData = new AppMonitorData();
		}
		myData.Items = items;
	}

	public int GetAutoReportMonitorCount()
	{
		using SqlConnection con = new SqlConnection(_logsContext.Database.GetConnectionString());
		using SqlCommand cmd = new SqlCommand("AutoReportMonitorCount", con);
		cmd.CommandType = CommandType.StoredProcedure;
		var param = cmd.Parameters.Add("@RowCount", SqlDbType.Int);
		param.Direction = ParameterDirection.Output;
		con.Open();
		cmd.ExecuteNonQuery();
		return (int)param.Value;
	}

	public async Task<int> GetAutoReportMonitorCountAsync()
	{
		using SqlConnection con = new SqlConnection(_logsContext.Database.GetConnectionString());
		using SqlCommand cmd = new SqlCommand("AutoReportMonitorCount", con);
		cmd.CommandType = CommandType.StoredProcedure;
		var param = cmd.Parameters.Add("@RowCount", SqlDbType.Int);
		param.Direction = ParameterDirection.Output;
		await con.OpenAsync();
		await cmd.ExecuteNonQueryAsync();
		return (int)param.Value;
	}

	private async Task<AppMonitorRow[]?> GetAppMonitorItems()
	{
		var items = await _logsContext.AppMonitorRows.FromSql($"EXEC ApplicationMonitorViewer @UseExcel = 'no'").ToArrayAsync();
		return items;
	}

	private async Task<AppMonitorData> GetAppMonitorData()
	{
		var items = await _logsContext.AppMonitorRows.FromSql($"EXEC ApplicationMonitorViewer @UseExcel = 'no'").ToArrayAsync();
		var data = new AppMonitorData();
		data.FailedEmailCount = GetAutoReportMonitorCount();
		data.Items = items;
		return data;
		//return results ?? new AppMonitorRow[0];
	}
}

[engineering87]

Hello @mnbob70,
can you try this: on IIS, ensure the correct environment used (IIS runs like Production and ignores launchSettings.json), so set ASPNETCORE_ENVIRONMENT or put the right connection string in appsettings.Production.json to hit the same DB as local. Also confirm the stored procedure sets the OUTPUT parameter and that your ADO.NET parameter is ParameterDirection.Output and read after ExecuteNonQuery().

[mnbob70]

Thank you for the suggestion but this is not a connection string or query issue. The application is using the same database and connection string whether running locally or on IIS. The stored procedure is correct because it works correctly locally and in SSMS. Also, the same database is queried for both the count and the list of items. I just changed the items stored procedure to return the count and it still does not have a >0 value in IIS. This is what my async method looks like with the stored procedure change:

	private async Task GetAppMonitorDataAsync()
	{
		var param1 = new SqlParameter("@p1", "no");
		var param2 = new SqlParameter("@p2", SqlDbType.Int);
		param2.Direction = ParameterDirection.Output;
		var items = await _logsContext.AppMonitorRows.FromSql($"EXEC ApplicationMonitorViewer @UseExcel={param1}, @FailedReportCount={param2} output").ToArrayAsync();
		myData = new AppMonitorData()
		{
			FailedEmailCount = (int)param2.Value,
			Items = items
		};
	}

The items are displayed but FailedEmailCount is still 0. Locally, FailedEmailCount is 17 just like all of my other attemps to fix this.

[mnbob70]

At this point I can only assume I'm experiencing a strange bug under IIS and I'm always extremely hesitant to assume a bug. Any query for int values somehow results in 0 being assigned while running under IIS. I've added a string to my stored procedure just for testing purposes and I'm only querying simple data synchronously. The stored procedure returns an int value (17) and a string value (String from proc). After assigning to two different variables, both int assignments become 0 while the string assignments work. Why is Blazor not accepting the int assignments?!!!

I've simplified this down to the following code:

	private int count2;
	private string? testString;
	private AppMonitorData? myData;

	protected override void OnInitialized()
	{
		GetAutoReportMonitorCount2();
		myData = new AppMonitorData()
		{
			FailedEmailCount = count2,
			TestValue = 13,
			TestString = testString
		};
	}

	public void GetAutoReportMonitorCount2()
	{
		using SqlConnection con = new SqlConnection(_logsContext.Database.GetConnectionString());
		con.Open();
		using SqlCommand cmd = new SqlCommand("AutoReportMonitorCount2", con);
		cmd.CommandType = CommandType.StoredProcedure;
		using SqlDataReader reader = cmd.ExecuteReader();
		while (reader.Read())
		{
			count2 = (int)reader["FailedEmailCount"];
			testString = (string)reader["TestString"];
		}
	}

The correct result when I run from Visual Studio:

The incorrect result running from production IIS server:

[mnbob70]

Talking to myself... Modifying the stored procedure works in some cases so I believe I've narrowed this down to some type of database permission issue even though I'm not receiving any errors.