We Keep Coding

Xamarin Database Connection Refuse

I'm trying to get connected to my own MySQL Database over the System.Data.SqlClient but every time i'm trying i'll get in the Timeout because of the server is unreachable. I also tried the MySQL Plugin but there i also get an Error. I think that the "APP" blocks the connection.
This is my Code:
public void connDB() {
SqlConnectionStringBuilder ConnString = new SqlConnectionStringBuilder();
ConnString.DataSource = "[Server-IP]";
ConnString.UserID = "[Username]";
ConnString.Password = "[Password]";
ConnString.InitialCatalog = "[DB-Name]";
ConnString.ConnectTimeout = 50;
SqlConnection sqlConn = new SqlConnection(ConnString.ToString());
sqlConn.Open();
}
At sqlConn.Open(); i get this message =>
System.Data.SqlClient.SqlException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.
The Server is normally responding and my server inputs are right.
Can anyone help me?

Get a rid of SqlConnection, which remains in Activity Monitor after being closed/disposed

I'm creating database, using ADO.NET. Basically, I'm executing SQL commands in next way:
private bool ExecuteSqlCommand(string command)
{
var success = true;
using (var connection = GetSqlConnection())
{
if (connection == null)
return false;
using (var myCommand = new SqlCommand("query", connection))
{
try
{
connection.Open();
myCommand.CommandText = command;
myCommand.ExecuteNonQuery();
}
catch (Exception ex)
{
success = false;
Log.LogMessage(string.Format("Unable to execute SQL command: {0}", ex.Message));
}
}
}
return success;
}
GetSqlConnection just gets some proper SqlConnection with connection string like
"Server={0}\\{1};User Id={2};Password={3};Application Name={4};"
It works well, and executes command properly, with one exception - according to Sql Manager Studio activity monitor, it remains as active connection even after method was executed.
According to question Why does my SqlConnection remain in the SSMS Processes list after closing it?, this is correct behavior, since connection might be reused. But the serius issue is, that later, READ_COMMITTED_SNAPSHOT command will be called for this database, while using different SqlConnection. Which leads to exception, since READ_COMMITTED_SNAPSHOT requires, that connection, which is used to call this command, should be the only connection to database.
I can't reuse this connection for further operations with database, since I use different connection string for them, with database specified as InitialCatalog (obviously, I can't use it, while database doesn't exist).
So, can I somehow remove this initial connection?

Execute SqlConnection.ClearPool This will mark all connections to be discarded instead of recycled.

Sql Connection Pool timeout

[Disclaimer] : I think I have read every stackoverflow post about this already
I have been breaking my head over this for quite some time now. I am getting the following exception in my asp.net web.api.
Exception thrown: 'System.InvalidOperationException' in mscorlib.dll
Additional information: Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached.
Most people suggested that I should look for leaked connections in my application. Here is my code. Now I am sure that I am not leaking any connections
public async Task<IEnumerable<string>> Get()
{
var ds = new DataSet();
var constring = "Data Source=xxx;Initial Catalog=xxx;User Id=xxx;Password=xxx;Max Pool Size=100";
var asyncConnectionString = new SqlConnectionStringBuilder(constring)
{
AsynchronousProcessing = true
}.ToString();
using (var con = new SqlConnection(asyncConnectionString))
using (var cmd = new SqlCommand("[dbo].[xxx]", con))
{
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.AddWithValue("#x1", 1);
cmd.Parameters.AddWithValue("#x2", "something");
await con.OpenAsync();
using (var rdr =await cmd.ExecuteReaderAsync())
{
if (rdr.HasRows)
{
ds.Load(rdr, LoadOption.OverwriteChanges, "MyTable");
}
rdr.Close();
con.Close();
ds.Dispose();
}
}
//I know this looks wrong, just an empty api method to show the code
return new string[] { "value1", "value2" };
}
The exception does not occur when I am using my local Sql Server. Only happens when I connect to our 'test server'. Are there anything else I can look at when trying resolve this issue. Like Sql server settings / network settings etc.
The stored procedure I call does not lock up the db I have checked for that as well. If that was the case it should have failed on my local Sql instance as well.
I am using jmeter to generate load, 1500 - threads(users). Surely I should be able to handle way more than that.
Thanks in advance

You have not specified any Connection Time out property, so it's 15 seconds default. using Max Pool Size=100 is not a good idea until you don't have proper hardware resources.
You started 1500 threads, so it seems that the some the threads keep waiting for 15 seconds to get their chance for connection opening. And as time goes out, you get the connection time out error.
So I think increasing the 'Connection Timeout' property in connection string may resolve your issue.

Cannot configure timeout from connection string

I have created this stored procedure in SQL Server 2008 R2:
CREATE PROCEDURE dbo.test AS
BEGIN
WAITFOR DEALY '00:00:40'
END
I have also written a C# console app to test the connect timeout property.
static void Main(string[] args)
{
OpenSqlConnection();
Console.ReadLine();
}
private static void OpenSqlConnection()
{
string connectionString = GetConnectionString();
using (SqlConnection connection = new SqlConnection(connectionString))
{
using (var command = new SqlCommand("dbo.test", connection) { CommandType = CommandType.StoredProcedure })
{
connection.Open();
Console.WriteLine("ConnectionTimeout: {0}", connection.ConnectionTimeout);
command.ExecuteNonQuery();
Console.WriteLine("Finished");
connection.Close();
}
}
}
static private string GetConnectionString()
{
return
"Data Source=test.com;Initial Catalog=test_db;Integrated Security=True;MultipleActiveResultSets=True;Connect Timeout=10; Application Name=Test";
}
There was a connection timeout exception returned as excepted (timeout in connection string < 40s). However, when I changed the Connect Timeout property to 120, I still got the same timeout exception. After some trial and error, it seems that the timeout value is always 30s regardless of my connection string value.
Is the connection timeout controlled by somewhere else? (if yes, where?)
Why the connect timeout value in connection string has no effect on my console app?
Update
Thanks all. I have just noticed that the command timeout is different from connection timeout(timeout in connection string).
Instead of changing my app.config, I would have to specify the CommandTimeout property as Sudipta Maiti suggested and recompile my code.
There is a similar issue in:
http://forums.asp.net/t/1197160.aspx?Can+you+change+command+timeout+via+the+connection+string+

Use CommandTimeout:
using (var command = new SqlCommand("dbo.test", connection) {
CommandType = CommandType.StoredProcedure })
{
connection.Open();
Console.WriteLine("ConnectionTimeout: {0}",
connection.ConnectionTimeout);
command.CommandTimeout = 120;
command.ExecuteNonQuery();
Console.WriteLine("Finished");
connection.Close();
}

I strongly suspect the given Timeout, it may not be enough to complete your operations. So make it Connection Timeout=30;
Connect Timeout -or- Connection Timeout by default the value will be 15 seconds. Based on your operation performance you might need to extend the seconds.
When a connection is returned to the pool, its creation time is compared with the current time, and the connection is destroyed if that time span (in seconds) exceeds the value specified by Connection Lifetime. This is useful in clustered configurations to force load balancing between a running server and a server just brought online.
A value of zero (0) causes pooled connections to have the maximum connection timeout.
There is a Sample Source almost same as yours.

SQL Server Error while pulling hundreds of records

I am getting this error when I try to get all the username password from production copied local database, I guess it is because of not closing the connection properly, but I am not sure how . I am using the Microsoft Enterprise Library, ant thought or comment about it?
Timeout expired. The timeout period elapsed prior to
obtaining a connection from the pool. This may have occurred
because all pooled connections were in use and max pool size was reached.
this is the mothod that is getting the username and password and producing the error.
private Model.UsernameandPass GetUsernamePass(string AccountNumber)
{
Model.UsernameandPass model = null;
string myConnection = System.Configuration.ConfigurationManager.ConnectionStrings[connectionName].ToString();
SqlDatabase db = new SqlDatabase(myConnection);
using (DbCommand command = db.GetStoredProcCommand("Get_TheUsernamePassWordFromProduction"))
{
db.AddInParameter(command, "AccountNumber", DbType.String, AccountNumber);
var result = db.ExecuteReader(command);
try
{
while (result.Read())
{
model = new Model.UsernameandPass();
model.Username = result.GetString(1);
model.Password = result.GetString(2);
}
}
catch (Exception ex)
{
}
}
db = null;
return model;
}
I am getting the error in this line after program runs for a while.
var result = db.ExecuteReader(command);

You're getting that error because a connection cannot be established, not only because they aren't being closed properly. Check permissions for the user you're trying to authenticate against the database with. Also be sure to call .open()/.close() when/if you are programatically opening/closing connections.
Check this link. You may want to increase your pool size, or check for long-running queries.