I have a SQL Server 2014 hosted on Windows server 2012.
I also have many windows services develop in c# that run on Windows Server 2012.
My services have different responsabilities... They then connect on different databases on the server mentionned above.
Sometimes, in a realy intermitent manner, one of the service gets the following SqlException... While they other are still working fine...
Message: The client was unable to establish a connection because of an error during connection initialization process before login. Possible causes include the following: the client tried to connect to an unsupported version of SQL Server; the server was too busy to accept new connections; or there was a resource limitation (insufficient memory or maximum allowed connections) on the server. (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.)
I googled for some troubleshooting info with no luck...
What appears to be strange, it that two service working on the same database on the same server but only one gets the error...
Related
I have an app service with hybrid connection enabled(on a VM in the same network with the SQL Sever) for me to access on prem SQL Server, which I don't own. However, the connectivity has been pretty unstable.
I am able to access to the SQL Server probably for maybe 5% of the tries and mostly I just get error
One or more errors occurred. (A connection was successfully established with the server, but then an error occurred during the pre-login handshake. (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.
I'm able to log in thru SSMS on the VM. Connection string should be alright since I can access locally(local network is the same network as the SQL Server).
Named instances use dynamic ports and UDP, which are not supported by Hybrid Connections. Suggest you using static port as Nick mentioned. Please refer to this document Connect to on-premises SQL Server from a web app in Azure App Service using Hybrid Connections to get more information.
provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.
What is your Windows version? When Windows versions that don't contain the leading zero fixes for TLS_DHE will display this error message. You can try to update windows version or disable the TLS_DHE ciphers to solve this issue. Please refer to this document.
I have read this thread, however unfortunately couldn't find the solution to my problem. I have an ASP.Net Core project (that's called Rent) and it works without any problem on my local machine. However, once I publish the project to the IIS (still in development mode) I get the below error
fail: Rent.Program[0]An error occured during migration
Microsoft.Data.SqlClient.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: SQL Network Interfaces, error: 50 - Local Database Runtime error occurred. Cannot create an automatic instance. See the Windows Application event log for error details.
---> System.ComponentModel.Win32Exception (0x89C50118): Unknown error (0x89c50118)
The connection string is called DefaultConnection and is the environment variable. Can anyone help me please? Can provide any additional information if required.
The first thing you should check is that your SQL Server instance is up and running and that your database is still available. This error means quite literally that it can't establish a connection to SQL Server from the Secret Server application.
And you can also check follow things in your environment:
Is something blocking the connection between your Secret Server server and SQL Server?
The standard SQL port is 1433. Check with your server administrator - is the Windows Firewall in use, blocking this port on your SQL server? Check with your network administrator - is there a firewall at some point in between that has closed off this port? Keep in mind that if you use a custom port for SQL, it need to be specified the Secret Server database connection using a SQLSERVER,port type of format.
On the server hosting your SQL Server database, is the SQL Server
service running?
Open services.msc or SQL Configuration Manager to view the status of your SQL Server service.
I have a SQL Server database which I connect to from my VB.net client application.
Everything works fine in most of the systems. But in a few new VMs the client application is unable to connect to SQL Server and it throws the error mentioned below. The strange thing is that I can use the same credentials (SQL Server authentication) to connect through SQL Server Management Studio in the same system.
A connection was successfully established with the server, but then an error occurred during the pre-login handshake. (provider: Named Pipes Provider, error: 0 - No process is on the other end of the pipe.)
The sample connection string used is as below
Data Source=[server name];Initial Catalog=[db name];Persist Security Info=True;User ID=[username];Password=[pass]
I have checked similar answers and have already tried the following
Made sure SQL Server is accepting remote connections
Made sure TCP and Named Pipes are enabled in SQL Server
Started SQL Server Browser service
Tried specifying IP address instead of server name
By reading related articles, some of them point eventually to SSH, TLS1.1 and TLS1.2 issues. I also suspect firewall, but because I do not have admin rights to the system, I am not able to check the inbound and outbound rules.
Any suggestions would help.
We have an older machine that hosts a bunch of test databases. It was working fine for years. One day a few months ago, we could no longer open SQL Admin on that machine. When you tried, you get the dreaded:
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)
Note that we are running everything on this one machine. We are not trying to connect over the network from another machine. I tried variations on MS's page and on various SO threads on the topic:
the firewall is off
the server is running, as is the name service
it is configured for remote connections
we've rebooted it
Again, this was all working fine, and we changed nothing on that machine. I suppose a Win update may have occurred.
On a lark, today I tried making a new DSN to the same server, using SQL Client 11. It saw the server in the combo (took a while), and the test connection worked fine. But SQLSM still fails!
Does anyone know what connection type the Native Client would use, and what that driver uses to populate the server list?
My suspicion is that something is wrong with the named pipes service. If ODBC uses named pipes, then I'm a bit stumped.
I have two SQL Servers : one in Dijon, France; one in Arvada, Colorado, US. A data replication has been set up between them.
Everything works fine when users try to connect to SQL Server 2008 R2 Dijon database.
BUT an error occurs when one of my users is trying to connect to SQL Server 2012 US database from a VB.Net application.
The error is :
"A connection was successfully established with the server, but then an error occurred during the login process (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.)"
This error shows up only for one user. The others can connect without any issue. I have maybe a clue about this. We already encountered connection issues for him, because he belonged to many AD security groups.
Here is the connection string :
Data Source=server\instance;Initial Catalog=db;Integrated Security=SSPI;Connection Timeout=0;
We have the same issue for a US user trying to connect to the same server. But not when he tries to connect to Dijon. Do you have any clue that could help me resolving this issue please ?
I checked StackOverflow threads and other solutions from the web, but nothing helped me...
Refer following URLs
Troubleshooting: Connection Forcibly Closed
TCP Provider, error:
connection was forcibly closed
Follow these steps
First goto services and check whether 'SQL Server Browser' service is started, if not start the service.
Open SQL Server Configuration Manager
Goto Protocols for MSSQLSERVER
Enable all protocols
Goto SQL Native Client
Select Client Protocols and and Enable All
Restart the SQL Server services.
Use .. (.NET Framework Data Provider for SQL Server) as provider
Connectionstring
Data Source=server\instance;Initial Catalog=;Persist Security Info=True;User ID=;Password=;Network Library=dbmssocn
It was, as I expected, a problem of Kerberos authentication because my user has too many AD security groups...
The solution is explained here : Problems with Kerberos authentication when a user belongs to many groups and here MaxTokenSize and Windows 8 and Windows Server 2012
If the authorization data for a user attempting to authenticate is larger than the MaxTokenSize, then the authentication fails for that connection using that protocol.
On Windows 7 and Windows Server 2008R2 , the MaxTokenSize (the default buffer size for Kerberos) is 12k. Its size has been increased in Windows 8 and Windows Server 2012 to 48k. It wasn't enough for my case.
I had to add a key in the registry HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\Kerberos\Parameters\MaxTokenSize (REG_DWORD type to the decimal value 65535).
Then I rebooted the server.
My user can now access data without error.