Re: MySqlException: Unable to connect to any of the specified MySQL hosts

[bronislav r]

I have that problem with MySQL 5.0.41 and .Net connector 5.2.2

The problem is, when I try to open several connections from different threads, often the calls to sqlconnection.open() result in

a) exception "Unable to connect to any of the specified MySQL hosts" if pooling=false

or

b) call never returns (hangs) if pooling = true.

The problem seems to go away if I serialize calls to conn.open() from different threads in this way:

static object lockDBObject = new object();

lock(lockDBObject)
{
conn.open();
}

Apparently there is some threading bug somewhere in .NET or in the Connector code.