Question

I am using FtpWebRequest to upload a file.
Facing a problem of which i am not getting solution.

While uploading a heavy file if network get disconnected then FTP server acquires lock on file being uploaded, now when user tries to re upload the same file then it get access denied error.

I have set TimeOut and ReadWriteTimeOut to 5 secs of FtpWebRequest on FTP Server it is 10 secs.
Even if i try to upload same file after an Hour then also same problem exist.

 // Get the object used to communicate with the server.
  request = (FtpWebRequest)WebRequest.Create(new Uri("ftp://" + FtpInfo.FtpServer.Trim() + "/" + FtpInfo.FtpFolderPath.Trim() + "/" + FileName.Trim()));
   request.Method = WebRequestMethods.Ftp.UploadFile;
   request.Proxy = null;

   // FTP site uses anonymous logon.
    request.Credentials = new NetworkCredential(FtpInfo.UserNameForFTP.Trim(), FtpInfo.PasswordForFTP.Trim());
    request.UsePassive = FtpInfo.UsePassive;
    request.KeepAlive = FtpInfo.KeepAlive;
    request.Timeout = FtpInfo.TimeOut; //Milliseconds
    request.UseBinary = true;
    request.ReadWriteTimeout = FtpInfo.TimeOut; //Milliseconds

                        FileInfo fi = new FileInfo(SourceLocation);
                        long length = fi.Length;
                        BytesUploaded = length;

                        long uploadSize = 0;
                        if (chunks == 0)
                        {
                            chunks = 1024;
                        }
                        else
                        {
                            buffLength = chunks;
                        }
                        byte[] buff = new byte[buffLength];
                        int contentLen;
                        using (FileStream fs = fi.OpenRead())
                        {
                            using (Stream strm = request.GetRequestStream())
                            {
                                contentLen = fs.Read(buff, 0, buffLength);
                                try
                                {
                                    while (contentLen != 0)
                                    {
                                        Dispatcher.Invoke(DispatcherPriority.Normal, (Action)delegate() { lblProgress.Content = "Uploading '" + FileName + "'......" + "Bytes Uploaded (" + uploadSize.ToString() + "/" + length.ToString() + ")"; });
                                        strm.Write(buff, 0, contentLen);
                                        uploadSize += contentLen;
                                        contentLen = fs.Read(buff, 0, buffLength);
                                    }
                                    strm.Close();
                                }
                                catch (Exception ex)
                                {
                                    if (strm!=null)
                                    {
                                        try
                                        {
                                            strm.Close();
                                        }
                                        catch
                                        {
                                            throw ex;
                                        }
                                    }
                                    throw ex;
                                }
                            }
                            fs.Close();
                        }


                        try
                        {
                            //requestStream.Close(); -orignal
                            fi = null;
                            request=null;
                        }
                        catch { }

Answer 1

This was problem related to the FTP Server we were using, when we switched FTP server to IIS then everything worked smoothly.
Thanks for all the help