In Python, when a socket loses its connection to the host, the socket will be closed by the operating system, this will result in errors if you try to read or write to the socket stream, this at least gives you a way to detect the loss of connection.
All you will need to do afterwards is create a new socket and attempt to reconnect to the host. When a loss of connectivity occurs between the client and server socket, the operating system closes the socket that was holding the connection open, so if you attempt to read or write to the socket stream, it will result in an exception. To detect a loss of connection, all you need to do is surround any socket read or write operations in a try-except statement that listens for a socket exception.
As the socket object is no longer useful after the connection is lost, it is necessary to create a new socket object this can be assigned to the initial socket variable. Once you have recreated the client socket, you can then try to reconnect to the server using the connect method.
The problem with this is that the issue that caused the loss of connection may still be affecting the system, this means the connect method could result in an exception such as a "ConnectionRefusedError" caused by the server not actively listening for connections. A simple solution to this issue is to place the connect method within a while loop and surround it with a try-except statement.
If the connection is successful, then the application will continue with the rest of the script, otherwise it will wait a few seconds and attempt to reconnect again.
The above script will keep the application within the while loop until it has successfully reconnected to the server socket.
Here we will create a simple local server and client that will both send and receive simple messages from each-other for as long as they are connected.
If the client loses connection to the server, it will try to reconnect. Name, string. NativeErrorCode, sex. Message, sex. Source, sex. StackTrace ; this. Message, ex. Source, ex. Shutdown SocketShutdown. Both ; this. InterNetwork, SocketType. Stream, ProtocolType. Close is called. Socket, SocketOptionName. Disconnect true ; log. AddSystemLog this. Format "Try Re-Connection Message, exc. Source, exc. Improve this question. I would advise you to look at async variants.
And for reconnecting, you'd better create a new socket for it. JeroenvanLangen reConnect method has already create a new socket. Isn't it? Tell me more detail.
It would be helpful. I see it's recreated. Why is the server code and the client code combined? Address already in use. Client applications usually need not call bind at all— connect chooses an unused port automatically. Cannot assign requested address. The requested address is not valid in its context. This normally results from an attempt to bind to an address that is not valid for the local computer. Network is down. A socket operation encountered a dead network.
This could indicate a serious failure of the network system that is, the protocol stack that the Windows Sockets DLL runs over , the network interface, or the local network itself. Network is unreachable. A socket operation was attempted to an unreachable network. This usually means the local software knows no route to reach the remote host. Network dropped connection on reset. The connection has been broken due to keep-alive activity detecting a failure while the operation was in progress.
Software caused connection abort. An established connection was aborted by the software in your host computer, possibly due to a data transmission time-out or protocol error. Connection reset by peer.
An existing connection was forcibly closed by the remote host. This error may also result if a connection was broken due to keep-alive activity detecting a failure while one or more operations are in progress. No buffer space available. An operation on a socket could not be performed because the system lacked sufficient buffer space or because a queue was full.
Socket is already connected. A connect request was made on an already-connected socket. Socket is not connected. A request to send or receive data was disallowed because the socket is not connected and when sending on a datagram socket using sendto no address was supplied.
Cannot send after socket shutdown. A request to send or receive data was disallowed because the socket had already been shut down in that direction with a previous shutdown call. By calling shutdown a partial close of a socket is requested, which is a signal that sending or receiving, or both have been discontinued.
Too many references. Too many references to some kernel object. Connection timed out. A connection attempt failed because the connected party did not properly respond after a period of time, or the established connection failed because the connected host has failed to respond. Connection refused. No connection could be made because the target computer actively refused it. This usually results from trying to connect to a service that is inactive on the foreign host—that is, one with no server application running.
Cannot translate name. Cannot translate a name. Name too long. A name component or a name was too long. Host is down. A socket operation failed because the destination host is down. A socket operation encountered a dead host. Networking activity on the local host has not been initiated. No route to host. A socket operation was attempted to an unreachable host. Directory not empty. Cannot remove a directory that is not empty. Too many processes. A Windows Sockets implementation may have a limit on the number of applications that can use it simultaneously.
WSAStartup may fail with this error if the limit has been reached. User quota exceeded. Ran out of user quota. Disk quota exceeded. Ran out of disk quota. Stale file handle reference. The file handle reference is no longer available. Item is remote. The item is not available locally. Network subsystem is unavailable. This error is returned by WSAStartup if the Windows Sockets implementation cannot function at this time because the underlying system it uses to provide network services is currently unavailable.
That they are not trying to use more than one Windows Sockets implementation simultaneously. If there is more than one Winsock DLL on your system, be sure the first one in the path is appropriate for the network subsystem currently loaded. The Windows Sockets implementation documentation to be sure all necessary components are currently installed and configured correctly.
The current Windows Sockets implementation does not support the Windows Sockets specification version requested by the application.
Successful WSAStartup not yet performed. The application may be accessing a socket that the current active task does not own that is, trying to share a socket between tasks , or WSACleanup has been called too many times.
Graceful shutdown in progress. No more results. Call has been canceled. The call has been canceled. Procedure call table is invalid. The service provider procedure call table is invalid.
This is usually caused by one or more of the function pointers being NULL. Service provider is invalid. The requested service provider is invalid. This error is also returned if the service provider returned a version number other than 2.
Service provider failed to initialize.
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