Calling Stored procedure inside a thread to update multiple records - asp.net

Question

I am trying to calla stored procedure for various unique entities . The stored procedure for a single entity takes about 33 secs. So I decided to call it using threads.
Here are some of trials I have done :
public bool ExecuteTaxRateLinkingParallel(int mapID, int createdBy)
{
try
{
int snapshotID = (int)(HttpContext.Current.Session[GlobalConstant.snapShotID]);
List<TaxEntity> taxEntities = new List<TaxEntity>();
List<Task> tasks = new List<Task>();
using (var ctx = new TopazDbContainer())
{
taxEntities = ctx.TaxEntities.AsParallel().Where(t => t.IsActive == true).ToList<TaxEntity>();
}
Parallel.ForEach<TaxEntity>(taxEntities, (entity) =>
{
//SqlConnection connection; SqlTransaction trans; SqlCommand command;
// break this into pieces of 5
var task = Task.Factory.StartNew(() =>
{
using (var pctx = new TopazDbContainer())
{
try
{
int taxEntityID = entity.TaxEntityID;
pctx.CommandTimeout = 5000;
//string connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["TOPAZDBConnectionStringParallel"].ConnectionString;
//connection = new SqlConnection(connectionString);
//command = new SqlCommand("dbo.[Usp_TaxRatesLinkingParallel]", connection);
//trans = connection.BeginTransaction();
//command.CommandType = CommandType.StoredProcedure;
//command.Parameters.AddWithValue("#MapID", mapID);
//command.Parameters.AddWithValue("#UserID", createdBy);
//command.Parameters.AddWithValue("#TaxEntityID", taxEntityID);
//command.Parameters.AddWithValue("#SnapshotID", snapshotID);
//connection.Open();
//command.CommandTimeout = 5000;
//command.ExecuteReader().AsParallel();
pctx.ContextOptions.LazyLoadingEnabled = true;
//pctx.ExecuteStoreCommand("Exec [Usp_TaxRatesLinkingParallel] #MapID={0},#UserID={1},#TaxEntityID={2},#SnapshotID{3}", new SqlParameter("MapID", mapID), new SqlParameter("UserID", createdBy), new SqlParameter("TaxEntityID", taxEntityID), new SqlParameter("SnapshotID", snapshotID));
var param = new DbParameter[] { new SqlParameter("UserID", createdBy), new SqlParameter("TaxEntityID", taxEntityID), new SqlParameter("SnapshotID", snapshotID) };
pctx.ExecuteStoreCommand("Exec [Usp_TaxRatesLinkingParallel] #MapID,#UserID,#TaxEntityID,#SnapshotID", param);
//var result = output.FirstOrDefault();
}
catch (TaskCanceledException tx)
{
}
catch (Exception e)
{
}
finally
{
pctx.SaveChanges();
pctx.Connection.Close();
}
}
}, TaskCreationOptions.PreferFairness);
tasks.Add(task);
try
{
Task.WaitAll(tasks.ToArray());
}
catch (AggregateException ae)
{
ae.Handle((x) =>
{
if (x is UnauthorizedAccessException)
{
return true;
}
else
{
return false;
}
});
}
catch (Exception ex)
{
throw ex;
}
});
return true;
}
catch (Exception ex)
{
TopazErrorLogs.AddTopazErrorLogBL(ex, 1, 1);
throw new TopazCustomException(GlobalConstant.errorMessage);
}
}
For some the above statements the SP seems like it runs fine but when I check from the application or from backend the records doesn't get updated.
Need help!

Answer 1

If you are not on .NET 4.5 yet, you can use these extension methods to execute your commands async.
using System.Diagnostics.Contracts;
using System.Threading.Tasks;
using System.Xml;
namespace System.Data.SqlClient
{
public static class SqlCommandExtensions
{
public static Task<SqlDataReader> ExecuteReaderAsync(this SqlCommand command)
{
Contract.Requires(command != null);
return ExecuteReaderAsync(command, null);
}
public static Task<SqlDataReader> ExecuteReaderAsync(this SqlCommand command, object state)
{
Contract.Requires(command != null);
return Task.Factory.FromAsync<SqlDataReader>(command.BeginExecuteReader, command.EndExecuteReader, state);
}
public static Task<XmlReader> ExecuteReaderXmlAsync(this SqlCommand command)
{
Contract.Requires(command != null);
return ExecuteReaderXmlAsync(command, null);
}
public static Task<XmlReader> ExecuteReaderXmlAsync(this SqlCommand command, object state)
{
Contract.Requires(command != null);
return Task.Factory.FromAsync<XmlReader>(command.BeginExecuteXmlReader, command.EndExecuteXmlReader, state);
}
public static Task<int> ExecuteNonQueryAsync(this SqlCommand command)
{
Contract.Requires(command != null);
return ExecuteNonQueryAsync(command, null);
}
public static Task<int> ExecuteNonQueryAsync(this SqlCommand command, object state)
{
Contract.Requires(command != null);
return Task.Factory.FromAsync<int>(command.BeginExecuteNonQuery, command.EndExecuteNonQuery, state);
}
}
}

Answer 2

It is not an asynchronous database query that you are doing here. Please have a look:
Asynchronous Database Calls With Task-based Asynchronous Programming Model (TAP) in ASP.NET MVC 4
Here is an example of an asynchronous database call with new async / await features:
public async Task<IEnumerable<Car>> GetCarsAsync() {
var connectionString =
ConfigurationManager.ConnectionStrings["CarGalleryConnStr"].ConnectionString;
var asyncConnectionString = new SqlConnectionStringBuilder(connectionString) {
AsynchronousProcessing = true
}.ToString();
using (var conn = new SqlConnection(asyncConnectionString)) {
using (var cmd = new SqlCommand()) {
cmd.Connection = conn;
cmd.CommandText = selectStatement;
cmd.CommandType = CommandType.Text;
conn.Open();
using (var reader = await cmd.ExecuteReaderAsync()) {
return reader.Select(r => carBuilder(r)).ToList();
}
}
}
}
You may find the detailed info inside the blog post.