错误记录-MySql.Data.MySqlClient.MySqlException (0x80004005): Timeout expired.

2019-10-17 14:53:25.026 +08:00 [ERR] Connection id "0HLQH64H76UL5", Request id "0HLQH64H76UL5:00000001": An unhandled exception was thrown by the application.
MySql.Data.MySqlClient.MySqlException (0x80004005): Unable to connect to any of the specified MySQL hosts. ---> MySql.Data.MySqlClient.MySqlException (0x80004005): Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not 
responding.
at MySql.Data.Common.StreamCreator.GetTcpStream(MySqlConnectionStringBuilder settings)
at MySql.Data.MySqlClient.NativeDriver.Open()
at MySql.Data.MySqlClient.NativeDriver.Open()
at MySql.Data.MySqlClient.Driver.Open()
at MySql.Data.MySqlClient.Driver.Create(MySqlConnectionStringBuilder settings)
at MySql.Data.MySqlClient.MySqlPool.CreateNewPooledConnection()
at MySql.Data.MySqlClient.MySqlPool.GetPooledConnection()
at MySql.Data.MySqlClient.MySqlPool.TryToGetDriver()
at MySql.Data.MySqlClient.MySqlPool.GetConnection()
at MySql.Data.MySqlClient.MySqlConnection.Open()
at System.Data.Common.DbConnection.OpenAsync(CancellationToken cancellationToken)
--- End of stack trace from previous location where exception was thrown ---
at YWAPI.Controllers.ValuesController.FindWarehouseList(YWWareshouseRequest request) in /app/Controllers/ValuesController.cs:line 60
at lambda_method(Closure , Object )
at Microsoft.Extensions.Internal.ObjectMethodExecutorAwaitable.Awaiter.GetResult()
at Microsoft.AspNetCore.Mvc.Internal.ActionMethodExecutor.AwaitableObjectResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
at System.Threading.Tasks.ValueTask`1.get_Result()
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeActionMethodAsync()
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeNextActionFilterAsync()
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Rethrow(ActionExecutedContext context)
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeInnerFilterAsync()
at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeNextResourceFilter()
at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Rethrow(ResourceExecutedContext context)
at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeFilterPipelineAsync()
at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeAsync()
at Microsoft.AspNetCore.Routing.EndpointMiddleware.Invoke(HttpContext httpContext)
at Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware.Invoke(HttpContext httpContext)
at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ProcessRequests[TContext](IHttpApplication`1 application)