报错：Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached. 问题
平静的一天，注定不平静
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Message: "Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached."
StackTrace: " at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection)
↵ at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
↵ at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
↵ at System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry)
↵ at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
↵ at System.Data.SqlClient.SqlConnection.Open()
↵ at Package.Accessfunction(String factory, String svTYPE, String userbarcode)"
ExceptionType: "System.InvalidOperationException"
Timeout expired 超时时间已到. 达到了最大池大小 错误及Max Pool Size设置
