Socket error coming and write log file for cloud's response

Question

Hello everyone, We have a cloud application in angular 6(client) and MVC 5 (server). From last 4-5 days our clients are complaining that our application is not running. some clients are accessing API for searching. and they are getting error SocketError: Failed to open TCP connection to :443 (getaddrinfo: No address associated with hostname) can you help why this error is coming? Our clients are getting this error once in a while but mostly on sunday. We contacted service provider they are saying this is not their error and check your code etc. So we want to maintain log file in which we will log all responsens from server. So how to do that? Any help would be appreciated. Thank you

Salman Beg · Answer

You can write it but if you have multiple methods then you can use Application_Error method inside global.asax. Follow this link also, https://www.google.com/amp/s/stackify.com/aspnet-mvc-error-handling/amp/

Salman Beg · Answer

Hey you need to maintain logs in each code. You need to use try catch block and in that add logs. Follow this link which explain clearly how to maintain logs, https://www.codeproject.com/Articles/1278018/Best-Logging-libraries-for-ASP-NET-MVC

Salman Beg · Answer

It should automatically call application_error() but not sure in your case why it is not working. If you want you can add try catch block also. Thanks.

dip s · Answer

ok. for example I added code in my post method which will generate exception dividebyzero To check whether exception handling working or not. But its not working. I tried to add break point at application_error() and LogError function but its not hitting break point so i am not able to understand whether it sworking or what is the issue? Because even log file is not generating. So i thought i need to add some code in controller like try catch or anything else. How can i check whether its working or not?

Salman Beg · Answer

Whenever you will get any error then automatically it will hit to Application_error() in global.aspx page. No need to write any other code in controller. Thanks

dip s · Answer

@salman Beg . I gone through some link about Application_error() in global.aspx My code in Global.aspx is as follows I have written LogError method to Log exceptions in textfile. protected void Application_Error( object sender, EventArgs e) { var exception = Server.GetLastError().GetBaseException(); LogError(exception.ToString()); Response.Clear(); Server.ClearError(); } private void LogError( string message) { try { string path = "D:/" + DateTime.Today.ToString( "dd-MM-yy" ) + ".txt" ; if (!File.Exists(path)) { File.Create(path).Close(); } using (StreamWriter w = File.AppendText(path)) { w.WriteLine( "
Log Entry :" ); w.WriteLine( "{0}" , DateTime.Now.ToString(CultureInfo.InvariantCulture)); string err = "Error in: " + System.Web.HttpContext.Current.Request.Url.ToString() + ".

Error Message:" + message; w.WriteLine(err); w.WriteLine( "==============================================" ); w.Flush(); w.Close(); } } catch { throw ; } My controller code is as follows. I have a post function public class MyController : ApiController { public string post (Student ObjStud) { ///Here comes code to add/save record into student table } } So do i need to write anything in controller for exception handling? or if there is any exception in Post method it will get catched and logged by application_error() method automatically. Thank you

dip s · Answer

ok i wl check. Thank you for your help.

dip s · Answer

@salman ok. Do I need to write try and catch to log error/exception for each and every function ? Means my controller has multiple functions with get and post methods. So i need to write try and catch for each and every function? Thank you

Salman Beg · Answer

Not sure exactly why this error is coming.i think sometimes it is not able to connect with tcp connection. But to know the exact error you need to log. Thanks

dip s · Answer

@salman Thank you . Can you help in why this socket error is coming?