I have a asp.net application deployed to Azure websites connecting to Azure SQL Database. This has been working fine for the last year, but last weekend I have started getting errors connecting to the database giving the following stacktrace.
[Win32Exception (0x80004005): Access is denied]
[SqlException (0x80131904): A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)]
This error comes and goes staying a few hours and then goes away for a few hours. The database is always accessible from my machine.
A few things that I have tried are:
Adding a "allow all" firewall rule (0.0.0.0-255.255.255.255) has no effect
Changing the connection string to use the database owner as credential has no effect.
what does have effect is to change the azure hosting level to something else. This resolves the issue temporarily and the website can access the database for a few hours more.
What could have have happened for this error to start showing up? The application hasn't been changed since August.
EDIT:
Azure support found that there was socket and port exhaustion on the instance. What the root cause for that is, is still unkown.
Craig is correct in that you need to implement SQLAzure Transient Fault Handling. You can find instructions here: https://msdn.microsoft.com/en-us/library/hh680899(v=pandp.50).aspx
From the article
You can instantiate a PolicyRetry object and wrap the calls that you
make to SQL Azure using the ExecuteAction method using the methods
show in the previous topics. However, the block also includes direct
support for working with SQL Azure through the ReliableSqlConnection
class.
The following code snippet shows an example of how to open a reliable
connection to SQL Azure.
using Microsoft.Practices.EnterpriseLibrary.WindowsAzure.TransientFaultHandling;
using Microsoft.Practices.EnterpriseLibrary.WindowsAzure.TransientFaultHandling.AzureStorage;
using Microsoft.Practices.EnterpriseLibrary.WindowsAzure.TransientFaultHandling.SqlAzure;
...
// Get an instance of the RetryManager class.
var retryManager = EnterpriseLibraryContainer.Current.GetInstance<RetryManager>();
// Create a retry policy that uses a default retry strategy from the
// configuration.
var retryPolicy = retryManager.GetDefaultSqlConnectionRetryPolicy();
using (ReliableSqlConnection conn =
new ReliableSqlConnection(connString, retryPolicy))
{
// Attempt to open a connection using the retry policy specified
// when the constructor is invoked.
conn.Open();
// ... execute SQL queries against this connection ...
}
The following code snippet shows an example of how to execute a SQL command with retries.
using Microsoft.Practices.EnterpriseLibrary.WindowsAzure.TransientFaultHandling;
using Microsoft.Practices.EnterpriseLibrary.WindowsAzure.TransientFaultHandling.AzureStorage;
using Microsoft.Practices.EnterpriseLibrary.WindowsAzure.TransientFaultHandling.SqlAzure;
using System.Data;
...
using (ReliableSqlConnection conn = new ReliableSqlConnection(connString, retryPolicy))
{
conn.Open();
IDbCommand selectCommand = conn.CreateCommand();
selectCommand.CommandText =
"UPDATE Application SET [DateUpdated] = getdate()";
// Execute the above query using a retry-aware ExecuteCommand method which
// will automatically retry if the query has failed (or connection was
// dropped).
int recordsAffected = conn.ExecuteCommand(selectCommand, retryPolicy);
}
The answer from Azure support indicated that the connection issues I was experiencing was due to port/socket exhaustion. This was probably caused by another website on the same hosting plan.
Some answers to why the symptoms were removed by changing hosting service level:
Changing the hosting plan helped for a while since this moved the virtual machine and closed all sockets.
Changing the hosting plan from level B to level S helped since azure limits the number of sockets on level B.
Okay, so after about an hour of searching through the web, I'm still having issues trying to create a local DB connection in ASP.net.
I need to create a connection to a local database file, and then simply loop through each record in a table. I'm not sure which file extension to use here (.aspx, .vbhtml, .cshtml?)
This is what I currently have from this W3school tutorial,
' Create local connection to DB file
#{
var db = Database.Open("Properties.mdf");
var query = db.Query("SELECT * FROM Properties");
}
<div id="pagewrap">
' Loop through records
#foreach(var row in query)
{
<p>#row.StreetAddress</p>
<p>#row.City</p>
<p>#row.State</p>
}
</div>
I'm currently getting a Connection string "Properties.mdf" was not found. error when running the above code. Any help is greatly appreciated.
That is because "Properties.mdf" is not a connection string. The mdf file cannot be opened just like this on its own - it needs a proper sql server database service. Exemplary connection string could look like this
var db = Database.Open("Server=.\SQLExpress;AttachDbFilename=Properties.mdf;Database=mydatabase;Trusted_Connection=Yes");
Although you need to have sql server installed (in this case your sql server instance would be called SQLExpress). and the connection string highly depends on what version of SQL Server you want to connect to.
Please refer to MSDN article.
I'm using SQL Server and ASP.NET. I have the following function:
Using js = daoFactory.CreateJoinScope()
Using tran = New Transactions.TransactionScope()
'...
tran.Complete()
End Using
End Using
However, the following exception is thrown:
The transaction manager has disabled its support for remote/network transactions.
Description of JoinScope:
Public Class JoinScope
Implements IJoinScope
Implements IDisposable
'...
End Class
I have worked this way in another application with the same environment without a problem, but here I have this problem. What could I do to fix the issue?
Make sure that the "Distributed Transaction Coordinator" Service is
running on both database and client.
Also make sure you check "Network DTC Access", "Allow Remote Client",
"Allow Inbound/Outbound" and "Enable TIP".
To enable Network DTC Access for MS DTC transactions
Open the Component Services snap-in.
To open Component Services, click Start. In the search box, type dcomcnfg, and then press ENTER.
Expand the console tree to locate the DTC (for example, Local DTC) for which you want to enable Network MS DTC Access.
On the Action menu, click Properties.
Click the Security tab and make the following changes:
In Security Settings, select the Network DTC Access check box.
In Transaction Manager Communication, select the Allow Inbound and Allow Outbound check boxes.
I had a store procedure that call another store Procedure in "linked server".when I execute it in ssms it was ok,but when I call it in application(By Entity Framework),I got this error.
This article helped me and I used this script:
EXEC sp_serveroption #server = 'LinkedServer IP or Name',#optname = 'remote proc transaction promotion', #optvalue = 'false' ;
for more detail look at this:
Linked server : The partner transaction manager has disabled its support for remote/network transactions
In my scenario, the exception was being thrown because I was trying to create a new connection instance within a TransactionScope on an already existing connection:
Example:
void someFunction()
{
using (var db = new DBContext(GetConnectionString()))
{
using (var transaction = new TransactionScope(TransactionScopeOption.Required, new TransactionOptions { IsolationLevel = System.Transactions.IsolationLevel.ReadUncommitted }))
{
someOtherFunction(); // This function opens a new connection within this transaction, causing the exception.
}
}
}
void someOtherFunction()
{
using (var db = new DBContext(GetConnectionString()))
{
db.Whatever // <- Exception.
}
}
I was getting this issue intermittently, I had followed the instructions here and very similar ones elsewhere. All was configured correctly.
This page: http://sysadminwebsite.wordpress.com/2012/05/29/9/ helped me find the problem.
Basically I had duplicate CID's for the MSDTC across both servers. HKEY_CLASSES_ROOT\CID
See: http://msdn.microsoft.com/en-us/library/aa561924.aspx section Ensure that MSDTC is assigned a unique CID value
I am working with virtual servers and our server team likes to use the same image for every server. It's a simple fix and we didn't need a restart. But the DTC service did need setting to Automatic startup and did need to be started after the re-install.
Comment from answer: "make sure you use the same open connection for all the database calls inside the transaction. – Magnus"
Our users are stored in a separate db from the data I was working with in the transactions. Opening the db connection to get the user was causing this error for me. Moving the other db connection and user lookup outside of the transaction scope fixed the error.
I post the below solution here because after some searching this is where I landed, so other may too. I was trying to use EF 6 to call a stored procedure, but had a similar error because the stored procedure had a linked server being utilized.
The operation could not be performed because OLE DB provider _ for linked server _ was unable to begin a distributed transaction
The partner transaction manager has disabled its support for remote/network transactions*
Jumping over to SQL Client did fix my issue, which also confirmed for me that it was an EF thing.
EF model generated method based attempt:
db.SomeStoredProcedure();
ExecuteSqlCommand based attempt:
db.Database.ExecuteSqlCommand("exec [SomeDB].[dbo].[SomeStoredProcedure]");
With:
var connectionString = db.Database.Connection.ConnectionString;
var connection = new System.Data.SqlClient.SqlConnection(connectionString);
var cmd = connection.CreateCommand();
cmd.CommandText = "exec [SomeDB].[dbo].[SomeStoredProcedure]";
connection.Open();
var result = cmd.ExecuteNonQuery();
That code can be shortened, but I think that version is slightly more convenient for debugging and stepping through.
I don't believe that Sql Client is necessarily a preferred choice, but I felt this was at least worth sharing if anyone else having similar problems gets landed here by google.
The above Code is C#, but the concept of trying to switch over to Sql Client still applies. At the very least it will be diagnostic to attempt to do so.
I was having this issue with a linked server in SSMS while trying to create a stored procedure.
On the linked server, I changed the server option "Enable Promotion on Distributed Transaction" to False.
Screenshot of Server Options
If you could not find Local DTC in the component services try to run this PowerShell script first:
$DTCSettings = #(
"NetworkDtcAccess", # Network DTC Access
"NetworkDtcAccessClients", # Allow Remote Clients ( Client and Administration)
"NetworkDtcAccessAdmin", # Allow Remote Administration ( Client and Administration)
"NetworkDtcAccessTransactions", # (Transaction Manager Communication )
"NetworkDtcAccessInbound", # Allow Inbound (Transaction Manager Communication )
"NetworkDtcAccessOutbound" , # Allow Outbound (Transaction Manager Communication )
"XaTransactions", # Enable XA Transactions
"LuTransactions" # Enable SNA LU 6.2 Transactions
)
foreach($setting in $DTCSettings)
{
Set-ItemProperty -Path HKLM:\Software\Microsoft\MSDTC\Security -Name $setting -Value 1
}
Restart-Service msdtc
And it appears!
Source: The partner transaction manager has disabled its support for remote/network transactions
In case others have the same issue:
I had a similar error happening. turned out I was wrapping several SQL statements in a transactions, where one of them executed on a linked server (Merge statement in an EXEC(...) AT Server statement). I resolved the issue by opening a separate connection to the linked server, encapsulating that statement in a try...catch then abort the transaction on the original connection in case the catch is tripped.
I had the same error message. For me changing pooling=False to ;pooling=true;Max Pool Size=200 in the connection string fixed the problem.
Can we close all known/unknown connections to database with the code?
I'm using Access database and my application gives the following error:
"Could not use ''; file already in use. "
I don't know which connection is opened and no closed, so is there a way to close all application's opened connections?
When working with disposable objects you should use using so they will get disposed, and in this case even closed, when leaving the using block. Your code should look something like:
using (var connection = new OleDbConnection(connectionString))
{
connection.Open();
// Do work here; connection closed on following line.
}
Read about OleDbConnection.
UPDATE: I missed that you were accessing an access database, so updated the code to use OleDbConnection instead.
I'm trying to rename my SQLite database file after I'm done using it, however the file still appears to be opened by SQLite even after all my connections are closed.
Here is an example of what I'm doing:
using (DbConnection conn = new SQLiteConnection("Data Source=test.db"))
{
conn.Open();
DbCommand command = conn.CreateCommand();
command.CommandText = "select id from test";
command.ExecuteScalar();
}
File.Move("test.db", "test.db.test");
The Move call throws an IOException. This is the only connection that I have to this database file. Once the application ends I can move the file manually without a problem. I've tried various things such as explicitly setting Pooling=false in the connection string, manually calling Close before the connection is disposed, explicitly starting and committing a transaction, but none of this seems to help. Is there a way to force SQLite to close/release the database file without exiting the application?
I presume you are using SQLite.Net? I have just tried your code and works without problem with SQLite.Net 1.0.65, in VS 2005 on Vista.
DBCommand is IDisposable. Maybe you need to call Dispose on it or create it in a using statement.