NHibernate + MySql 间歇性超时异常

Question

我刚刚将我的 NHibernate 应用程序从 SQL Server 迁移到 MySql。一切似乎都很好，除了我得到间歇性的 TimeoutExceptions。我可以找到很多关于 MySql 超时的信息，甚至是one blog post 关于 Hibernate + MySql + C3PO （不管是什么）的超时信息。但是没有关于如何调整 NHib 来阻止这个问题。你知道吗？

这是堆栈跟踪：

NHibernate.TransactionException: Begin failed with SQL exception ---> System.TimeoutException: 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 ---> System.IO.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. ---> System.Net.Sockets.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
   at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)
   at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
   --- End of inner exception stack trace ---
   at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
   at MyNetworkStream.Read(Byte[] buffer, Int32 offset, Int32 count)
   --- End of inner exception stack trace ---
   at MyNetworkStream.HandleOrRethrowException(Exception e)
   at MyNetworkStream.Read(Byte[] buffer, Int32 offset, Int32 count)
   at MySql.Data.MySqlClient.TimedStream.Read(Byte[] buffer, Int32 offset, Int32 count)
   at System.IO.BufferedStream.Read(Byte[] array, Int32 offset, Int32 count)
   at MySql.Data.MySqlClient.MySqlStream.ReadFully(Stream stream, Byte[] buffer, Int32 offset, Int32 count)
   at MySql.Data.MySqlClient.MySqlStream.LoadPacket()
   at MySql.Data.MySqlClient.MySqlStream.ReadPacket()
   at MySql.Data.MySqlClient.NativeDriver.ReadOk(Boolean read)
   at MySql.Data.MySqlClient.NativeDriver.SetDatabase(String dbName)
   at MySql.Data.MySqlClient.Driver.SetDatabase(String dbName)
   at MySql.Data.MySqlClient.MySqlConnection.ChangeDatabase(String databaseName)
   at MySql.Data.MySqlClient.MySqlConnection.Open()
   at NHibernate.Connection.DriverConnectionProvider.GetConnection()
   at NHibernate.AdoNet.ConnectionManager.GetConnection()
   at NHibernate.Impl.SessionImpl.get_Connection()
   at NHibernate.Transaction.AdoTransaction.Begin(IsolationLevel isolationLevel)
   --- End of inner exception stack trace ---
   at NHibernate.Transaction.AdoTransaction.Begin(IsolationLevel isolationLevel)
   at NHibernate.Transaction.AdoTransaction.Begin()
   at NHibernate.AdoNet.ConnectionManager.BeginTransaction()
   at NHibernate.Impl.SessionImpl.BeginTransaction()

Answer 1

我使用 MYSQL 数据库在 Rackspace 云上运行 NHibernate。我发现我正在超时，因为连接由于睡眠而处于半开放状态。最终我的连接用完了，我的网站超时了。

最后我将Pooling=false; 添加到我的连接字符串中。我不确定这是否是最终解决方案，但它已经解决了我的问题。

您可以在 MySQL 编辑器中使用 show processlist 检查休眠连接...