The time to open the home page of one of the “legacy” applications I was working on was slowly increasing over time. After a quick investigation it looked like there a couple of Azure SQL stored procedures which were called many times as the home page was opening were the problem.
The application used a combination of ADO.Net and Dapper to access the Azure SQL database, so Stack Overflow MiniProfiler looked like a good option.
There were quite a few samples online like the one below which “inspired” my approach.
using (SqlConnection connection = new SqlConnection(_configuration.GetConnectionString("default")))
{
using (ProfiledDbConnection connection = new ProfiledDbConnection((IDbConnection)connection, MiniProfiler.Current))
{
await connection.OpenAsync();
using (ProfiledDbCommand command = (ProfiledDbCommand)connection.CreateCommand())
{
command.CommandText = @"SELECT [StockItemID] as ""ID"", [StockItemName] as ""Name"", [RecommendedRetailPrice], [TaxRate] FROM [Warehouse].[StockItems];
command.CommandType = CommandType.Text;
using (ProfiledDbDataReader reader = (ProfiledDbDataReader)await command.ExecuteReaderAsync())
{
var rowParser = reader.GetRowParser<Model.StockItemListDtoV1>();
while (await reader.ReadAsync())
{
response.Add(rowParser(reader));
}
await reader.CloseAsync();
}
}
await connection.CloseAsync();
}
}
A simple modification of the WebAPI Dapper PerformanceProfiling project program.cs file enabled MiniProfiler for the project.
public static void Main(string[] args)
{
var builder = WebApplication.CreateBuilder(args);
// Add services to the container.
builder.Services.AddTransient<IDapperContext>(s => new DapperContext(builder.Configuration));
builder.Services.AddControllers();
builder.Services.AddMiniProfiler(options =>
{
options.RouteBasePath = "/profiler";
//options.SqlFormatter = new StackExchange.Profiling.SqlFormatters.InlineFormatter();
options.TrackConnectionOpenClose = true;
//options.PopupShowTrivial = false
});
var app = builder.Build();
app.UseMiniProfiler();
// Configure the HTTP request pipeline.
app.UseHttpsRedirection();
app.MapControllers();
app.Run();
}
For simple Dapper calls, the modifications to WebAPI controllers were minimal, and could be done largely with Visual Studio 2022 “search & replace.”
[HttpGet("Dapper")]
public async Task<ActionResult<IEnumerable<Model.StockItemListDtoV1>>> GetDapper()
{
IEnumerable<Model.StockItemListDtoV1> response;
using (IDbConnection db = dapperContext.ConnectionCreate())
{
response = await db.QueryAsync<Model.StockItemListDtoV1>(sql: sqlCommandText, commandType: CommandType.Text);
}
return this.Ok(response);
}
The World Wide Importers database has approximately 250 StockItems which was representative of one of the problematic queries.
[HttpGet("DapperProfiled")]
public async Task<ActionResult<IEnumerable<Model.StockItemListDtoV1>>> GetDapperProfiled()
{
IEnumerable<Model.StockItemListDtoV1> response;
using (IDbConnection db = new ProfiledDbConnection((DbConnection)dapperContext.ConnectionCreate(), MiniProfiler.Current))
{
response = await db.QueryAsync<Model.StockItemListDtoV1>(sql: sqlCommandText, commandType: CommandType.Text);
}
return this.Ok(response);
}
When I executed the GetDapperProfiler() method of the StockItems controller on my development box it took roughly 2.4 seconds.
I sometimes ran the website on my development box so when I used “toggle trivial gaps” it was easier to see what where the delays were.
When I executed the GetDapperProfiler() method of the StockItems controller running in an Azure AppService it took roughly 20 mSec.
In one application a QueryMultipleAsync is used to retrieve information about a product and a list of its attributes. The World Wide Importers database has Invoices which have invoice lines and Transactions which was representative of another problematic query.
[HttpGet("DapperProfiledQueryMultiple")]
public async Task<ActionResult<IEnumerable<Model.StockItemListDtoV1>>> GetDapperProfiledQueryMultiple([Required][Range(1, int.MaxValue, ErrorMessage = "Invoice id must greater than 0")] int id)
{
Model.InvoiceSummaryGetDtoV1 response = null;
using (ProfiledDbConnection db = new ProfiledDbConnection((DbConnection)dapperContext.ConnectionCreate(), MiniProfiler.Current))
{
var invoiceSummary = await db.QueryMultipleAsync("[Sales].[InvoiceSummaryGetV1]", param: new { InvoiceId = id }, commandType: CommandType.StoredProcedure);
response = await invoiceSummary.ReadSingleOrDefaultAsync<Model.InvoiceSummaryGetDtoV1>();
if (response == default)
{
return this.NotFound($"Invoice:{id} not found");
}
response.InvoiceLines = await invoiceSummary.ReadAsync<Model.InvoiceLineSummaryListDtoV1>();
response.StockItemTransactions = await invoiceSummary.ReadAsync<Model.StockItemTransactionSummaryListDtoV1>();
}
return this.Ok(response);
}
I couldn’t see any results for reading the StockItem Invoice lines and Transactions so I wrapped each ReadAsync with a MiniProfiler.Current.Step.
[HttpGet("DapperProfiledQueryMultipleStep")]
public async Task<ActionResult<IEnumerable<Model.StockItemListDtoV1>>> GetDapperProfiledQueryMultipleStep([Required][Range(1, int.MaxValue, ErrorMessage = "Invoice id must greater than 0")] int id)
{
Model.InvoiceSummaryGetDtoV1 response = null;
using (IDbConnection db = new ProfiledDbConnection((DbConnection)dapperContext.ConnectionCreate(), MiniProfiler.Current))
{
SqlMapper.GridReader invoiceSummary;
using (MiniProfiler.Current.Step("db.QueryMultipleAsync"))
{
invoiceSummary = await db.QueryMultipleAsync("[Sales].[InvoiceSummaryGetV1]", param: new { InvoiceId = id }, commandType: CommandType.StoredProcedure);
}
using (MiniProfiler.Current.Step("invoiceSummary.ReadSingleOrDefaultAsync"))
{
response = await invoiceSummary.ReadSingleOrDefaultAsync<Model.InvoiceSummaryGetDtoV1>();
}
if (response == default)
{
return this.NotFound($"Invoice:{id} not found");
}
using (MiniProfiler.Current.Step("invoiceSummaryLine.ReadAsync"))
{
response.InvoiceLines = await invoiceSummary.ReadAsync<Model.InvoiceLineSummaryListDtoV1>();
}
using (MiniProfiler.Current.Step("TransactionSummary.ReadAsync"))
{
response.StockItemTransactions = await invoiceSummary.ReadAsync<Model.StockItemTransactionSummaryListDtoV1>();
}
}
return this.Ok(response);
}
With larger lists every so often there were ReadAsync calls that took a more than a “trivial” amount of time. I surmise was some sort of batching done by the underlying ReadAsync + NextResultAsync methods of a SqlDataReader.
Need to investigate the use of
using (IDbConnection db = new ProfiledDbConnection(new SqlConnection(_configuration.GetConnectionString("default"), MiniProfiler.Current))
{
//...
}
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