"There is already an open DataReader associated with this Command which must be closed first."

This can happen if you execute a query while iterating over the results from another query. I ran into this issue when I called another async call while I was executing one result.

public async Task<IActionResult> GetTicketsInventory(int customerID, int accountID)
        {
            var service_response = await this.ticketsService.GetTicketsInventory(customerID, accountID);
            List<TicketsInventoryCO> items = service_response.Response.ToConvert();

               // this is my second call where i am trying to get results based on some condition
               // to get customer names
                var customer_response = await this.customerService.GetAllMobilityCustomers();

            return ProcessServiceResponse(
                apiContext,
                service_response,
                items,
                null);

        }

This can be easily solved by allowing MARS in your connection string. Add MultipleActiveResultSets=true to the provider part of your connection string (where Data Source, Initial Catalog, etc. are specified). Sample connection string

 "CoreCS": "Data Source=xxx.xxx.xxx.xxx;Initial Catalog=Mobility;Integrated Security=False;User Id=sa; Password=xxxxxx;Max Pool Size=20; Connection Timeout=10;MultipleActiveResultSets=true;",

Doloto – Download time optimizer for web 2.0 apps

Doloto is an AJAX application optimization tool, useful for large and complex Web 2.0 applications that contain a lot of code. Doloto analyzes AJAX application workloads and automatically performs code splitting of existing large Web 2.0 applications. After being processed by Doloto, an application will initially transfer only the portion of code necessary for application initialization.

Requirements

• Minimum: .NET Framework 3.5 (in US English only)

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Walkthrough Doloto