I'm trying to connect SQL server in my virtual machine with following connection string: "Server=qqvm;Database=a_test;Integrated Security=False;User Id=sa;Password=<pass>;Connect Timeout=0"
Firstly I had 'Network connection' exception with inner 'Access Denied' exception with empty stack trace. I did some digging and enabled 'Named Pipes' in SQL Configuration Manager.
After that I got this exception:
Connection Timeout Expired. The timeout period elapsed while attempting to consume the pre-login handshake acknowledgement. This could be because the pre-login handshake failed or the server was unable to respond back in time. The duration spent while attempting to connect to this server was - [Pre-Login] initialization=11281; handshake=1;
However, I'm still able to connect via SQL Management Studio to that server remotely. Any ideas?
Finally in my case specifying IP address instead of qqvm name solved the problem. Still don't know why, though. It worked a week ago.
Related
I recently replaced an on-prem MySQL server with Azure Database for MySQL. I have a .NET 6 C# application and it works when connected to the on-prem, but has a problem with the Azure DB. Both databases are version 5.7.32.
When the app is connected to the Azure DB, all of the SQL queries work except for one. That one SQL query throws the error shown below. The query is pretty ugly and has a lot of joins and nested selects, but it works with the on-prem. I can get the query to work if I remove some of the joins.
Is there anything else I can do to troubleshoot this or get a better understanding of what the problem is? Right now, it looks like I have to refactor the query, but I really would like more detail on what the problem was.
MySql.Data.MySqlClient.MySqlException
HResult=0x80004005
Message=Fatal error encountered during command execution.
Source=MySql.Data
StackTrace:
at MySql.Data.MySqlClient.MySqlCommand.ExecuteReader(CommandBehavior behavior)
at MySql.Data.MySqlClient.MySqlCommand.ExecuteReader()
at XXXX.cs:line XXXX
This exception was originally thrown at this call stack:
[External Code]
Inner Exception 1:
MySqlException: Fatal error encountered attempting to read the resultset.
Inner Exception 2:
MySqlException: Reading from the stream has failed.
Inner Exception 3:
IOException: Unable to read data from the transport connection: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond..
Inner Exception 4:
SocketException: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.
We are using SQLLocalDB to connect to a local database. No network access is required - C# Client application is on the same machine as SQLLocalDB. Sometimes I get the following error (only seems to happen on some PCs):
Microsoft.SqlServer.Management.Common.ConnectionFailureException: Failed to connect to server (localdb)\myserverinstancename. ---> System.Data.SqlClient.SqlException: Connection Timeout Expired. The timeout period elapsed while attempting to consume the pre-login handshake acknowledgement. This could be because the pre-login handshake failed or the server was unable to respond back in time. The duration spent while attempting to connect to this server was - [Pre-Login] initialization=27888; handshake=0; ---> System.ComponentModel.Win32Exception: The wait operation timed out
Oddly, it seems to happen if the PC is offline, and if connected to any sort of internet connection and retried, the issue goes away. However, in most cases the connection works fine even when there is no connection.
The closest I've found to my problem is this: Connection to SQL Server Works Sometimes
But that is discussing full SQL Server, rather than SQLLocalDB, and the solution uses "Sql Server Configuration Manager", which doens't work with SQLLocalDB.
My questions:
Does SQLLocalDb use IPv6/TCP for some reason, even when on the same PC?
Is there a way to change these settings for SQLLocalDB?
Or is there a different cause for this issue?
Edit: With help from some of the comments below I realised that the line that fails is when it calls a database creation script. The initial attempt at connection seems to work, but when I run my creation script it throws a "Failed to connect to server".
/// This line works
var server = new Server("(localdb)\myserverinstancename");
/// this line works 99% of the time, but sometimes "failed to connect to server"
server.ConnectionContext.ExecuteNonQuery(databaseCreationScript);
I have a Windows Service(c#) that receives data and inserts it into DB using Entity Framework 6. Database is SQL Server 2014 Enterprise Edition. Both (Service and DB) are hosted on same VPS( Windows Server 2008 R2 with 4 GB RAM). The load on the server and service is too low, approx 60 records per minute.
Now intermittently I get the below error in Logs:
Exception:
The underlying provider failed on Open.
Inner Exception:
System.Data.SqlClient.SqlException (0x80131904): Connection Timeout
Expired. The timeout period elapsed during the post-login phase. The
connection could have timed out while waiting for server to complete
the login process and respond; Or it could have timed out while
attempting to create multiple active connections. The duration spent
while attempting to connect to this server was - [Pre-Login]
initialization=0; handshake=7145; [Login] initialization=0;
authentication=0; [Post-Login] complete=7387; --->
System.ComponentModel.Win32Exception (0x80004005): The wait operation
timed out
Any help regarding fixing this shall be greatly appreciated.
EDIT
Connection String:
Data Source=.;Initial Catalog=wheeltrack;UID=wheeltrack;PWD=wheeltrack; MultipleActiveResultSets=true;Max Pool Size=1000;
I have a scenario in My programmer to check database connection and if database connection available then proceed else try to reconnect it.
I want to fetch DB time using "SELECT GETDATE()" statement. First time when DB connects it runs successfully and when after disconnect and connect DB and trying to fetch DB time it give me below error.
A transport-level error has occurred when sending the request to the server. (Provide: TCP Provider, error: 0 – An existing connection was forcibly closed by the remote host).
Can anyone help me to sort out this Problem?
I took an old software made by someone else, which need to connect to a database with the .mdf extension.
But when I run the software, I have an error 26. I have obviously checked Google and it seems the the main problem is the firewall. But if I disable it the problem doesn't dissapear.
Here is the code for connect the database :
DataClasses1DataContext db = new DataClasses1DataContext(Environment.CurrentDirectory + "\\bddgestionvin.mdf");
I've noticed, when I try to connect the database with the datacontext class it fail too with the same error 26. (see attached screenshot below)
The string connection used by this class is :
Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\bddgestionvin.mdf;Integrated Security=True;Connect `Timeout=30;User Instance=True`
I know I'm a little vague but I never did that kind of stuff (connect to a .mdf database) And the code is not mine, feel free the ask further explanation / code. Any help is welcome !
P.S The error message is
SqlException was unhandled 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: 26 - Error
Locating Server/Instance Specified)
(Sorry for the french software)
Hi I don't know you may see these steps. Make sure that these steps should pass.
The reason that we get this error message is the client stack could
not receive SSRP response UDP packet from SQL Browser. It's easy to
isolate the issue. Here are the steps:
1) Make sure your server name is correct, e.g., no typo on the name.
2) Make sure your instance name is correct and there is actually such
an instance on your target machine. [Update: Some application converts
\ to . If you are not sure about your application, please try both
Server\Instance and Server\Instance in your connection string]
3) Make sure the server machine is reachable, e.g, DNS can be resolve
correctly, you are able to ping the server (not always true).
4) Make sure SQL Browser service is running on the server.
5) If firewall is enabled on the server, you need to put
sqlbrowser.exe and/or UDP port 1434 into exception.
You can read more from here
You can also try PortQry and validate your firewall does not block SQL Browser UDP packet
A network-related or instance-specific error occurred while establishing a connection to SQL Server. Failed to establish a connection with SQL Server.
The server was not found or was not accessible.
May be server is stopped, you don't have permission to access the server, or the instance name is not correct .
Verify that the instance name is correct and that SQL Server is configured to allow remote connections.
Please goto SSMS and try connecting the server. Verify the SQL Server is running and your account is configured to access the service.
(provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
Thanks