Today a Microsoft Windows machine was unable to use the official MySQL client called "MySQL Connector/ODBC" to connect to a different MySQL server on a GNU/Linux machine, in the same LAN, via TCP/IP, standard port 3306, listening on all interfaces and without firewalls.
The connection from the Microsoft Windows client failed with this error message:
Connection Failed
[MySQL][ODBC 8.0(a) Driver] Can't open named pipe to host: xxx pipe: Mysql (s):
Notes
there is no firewall in the LAN
the port is worldwide opened
the credentials are OK
Question
Since this error message is nonsense... what's wrong here?
It seems there is a bug in the MySQL connector, at least version 8.0.
The client is ignoring your check on the TCP/IP option and it's using a legacy connection method called Named Pipe that it's not supported by your server (and should not - to be honest).
To make sure that the client does not use the Named Pipe method, select it, empty the text field (the one that in the example contains the text "Mysql"), and select again TCP/IP.
Now it will work!
It would be nice to discover if it exists an upstream bug in MySQL for that.
Related
I have a trivial VB script which I am using to connect to a MySQL database on a Windows Server (2012 R2).
It's all super simple, out of the box "connect to MySql example" stuff.
I have verified that MySQL is listening on all local IPV4 addresses. I can connect with MySQL workbench with the same parameters. Yet I get a weird error when connecting via my program:
An address incompatible with the requested protocol was used
My connect string is as follows:
"server=127.0.0.1;database=test;uid=xx;pwd=xx"
It appears the connection tries to use IPV6 when connecting. How is this possible?
I suspect some kind of firewall is modifying or blocking my network connection, but it is a "new" machine for me and I don't know what's installed.
The problem was due to an old MySQL Connector DLL (MySQL.Data.dll) version which was either incompatible with Windows (hence the networking error message) or the version of MySQL I'm running. After upgrading the dll, the connection worked properly.
This may help out someone who has a similar problem, as the error is highly misleading.
i can't hosting to connect to mysql database on linux i have this error message :
Unable to connect to any of the specified MySQL hosts
i need your help thx; this is my code
I suspect this message came from an exception thrown by your con.Open() call. The message means your attempt to Open() the connection failed because Connector/Net (the .net driver for mySQL) couldn't find the server you asked for. (Never mind the pluralization in "any of the specified MySQL hosts" ; that is for a loadbalancing / failover feature you're probably not using.)
If it took a few seconds for con.Open() to throw the exception, that means there was a timeout. That means the host at x.x.x.x did not respond at all, probably because it's not there or behind a firewall. If you're trying to connect from your home or office to a MySQL server at a hosting service, you may need to go into the hosting service's control panel and whitelist your own machine's IP address.
If Open() threw its exception quickly, it means the host is there, but it is not running a MySQL server.
Pro tip: Always wrap your Open() calls in their own try{}catch(){} clauses; failed database connection attempts are not an unexpected occurrence. Here is an explanation.
First of all I apologize for my English is not perfect.
I'm trying to connect to mysql database remotely.
I have already done the basic steps such as, for example, comment the bind address in my.cnf.
I gave permissions to the appropriate users in MySQL.
I tried with my friend to do it connect to the database, and it worked but we were in the same room with the same router.
Now I'm home and I tried to connect my friend, but I always get error:
ERROR 2003 (HY000): Can not connect to MySQL server ....
Maybe it's a problem of my home router? I can not even do the telnet.
P.S. I've also taken steps to set the firewall.
Some reasons for that,
mysqld is not running on the local host. Check your operating
system's process list to ensure the mysqld process is present.
You're running a MySQL server on Windows with many TCP/IP connections
to it. If you're experiencing that quite often your clients get that
error, you can find a workaround here: Section B.5.2.2.1, “Connection
to MySQL Server Failing on Windows”.
Check whether the server is running on that host by executing telnet
some_host 3306 and pressing the Enter key a couple of times. (3306 is
the default MySQL port number. Change the value if your server is
listening to a different port.) If there is a MySQL server running
and listening to the port, you should get a response that includes
the server's version number. If you get an error such as telnet:
Unable to connect to remote host: Connection refused, then there is
no server running on the given port.
Look at this mySQL full documentation, it will be helpful.
I am continuously getting below error while connecting to mysql-
Can\'t connect to MySQL server on /ip/address
but mysql is not generating any log for this error. I have below entries in my.cnf file
log=/var/log/mysql_err.log
log-error=/var/log/mysql/mysql_error.log
I am using correct credentials. No issue of conections.
Now how will I determine the exact issue If I'll not get any log ?
Any Idea, how to solve this ?
This is not surprising:
the server can only log an incident it is aware of. However your client does not even reach the server at all! So how should the server know some client has attempted to contact it?
The error message you get clearly indicates that you do have a connection issue.
You can easily make a test to check the most common problems: just open a telnet connection from the system trying to connect to the system the sql server runs on, connect to the mysql port: telnet <ip-of-mysql-server> mysql
On typical unixoid systems "mysql" will be substituted by the "well known port number of mysql, which is 3306. otherwise you have to specify it manually. Do you get a connection at all? I would guess not. This means either the mysql server is not listening where expected (not running or configured otherwise) or the connection is blocked on network level (firewall).
I am trying to connect remotely to SQL Server 2008 R2 Express on a server running Windows Server 2008 R2. I receive the following error:
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: TCP
Provider, error: 0 - 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.)
I think the problem might be related to my connection string, because I am not sure exactly what it should be. I understand the connection string should take the form:
Data Source=123.123.123.123\InstanceName;Initial Catalog=MyDBName;user id=MyUserName;password=MyPassword;
The instance name of my SQL Server installation takes the form ComputerName\SQLEXPRESS. This is what I see when I log in to Management Studio on the server. So should the connection string begin with
Data Source=123.123.123.123\ComputerName\SQLEXPRESS
This looks wrong because of all the slashes. I have tried to omit the computer name thus:
Data Source=123.123.123.123\SQLEXPRESS
I also read somewhere that you can specify a port so I have also tried
Data Source=123.123.123.123,1433\SQLEXPRESS
because I understand that 1433 is the TCP port used by SQL Server and
Data Source=123.123.123.123,1434\SQLEXPRESS
because I understand that 1434 is the UDP port used by SQL Server browser.
I have also tried every combination of these and they all give the same error.
These are the steps I have taken to enable remote browsing on the server:
In Management Studio, right click the instance, go to Properties, Security and check SQL Server and Windows Authentication Mode. On the connections tab I have checked "Allow remote connections to this computer".
In SQL Server Configuration Manager I have enabled all four connection options (Shared Memory, Named Pipes, TCPIP and Via) under every node they occur. Under protocols for SQL Express I have tried specifying port 1433 and also leaving it blank with TCP Dynamic Ports set to 0 (which I think is meant to enable dynamic ports).
I have created firewall exceptions for TCP Port 1433, UDP Port 1434, and program exceptions for sqlservr.exe and sqlbrowser.exe.
If someone could tell me which of the four versions of the DataSource part of the connection string I should be using it would be a great help, even if it did not solve the problem. It would mean that everything I try subsequently I would only have to test once instead of four times.
Thanks in advance for any help!
Where did you enter the firewall exceptions, on your machine, on the server, or both?
The second connection string is the only really valid one. Can you telnet to the server on port 1433? Can you connect to the instance from Management Studio remotely and the problem is only from your code where the connection string is? Did you try running the same code on the server? Did you try forcing TCP/IP (vs. named pipes/shared memory etc) adding the following parameter to your connection string:
Network=DBMSSOCN;
This question comes up quite a lot and I'm sure you're hitting something that others have hit before. Have you gone through this article, "How to troubleshoot connecting to the SQL Server Database Engine"? Also there are 20+ questions on here that mention this error message and Express, according to this search result. I suggest double-checking your settings against some of the items in those answers that solved the issue for other users.