Server System Variables • named_pipe_full_access_group • net_buffer_length (Windows only.) The access control granted to clients on the named pipe created by the MySQL server is set to the minimum necessary for successful communication when the  named_pipe  system variable is enabled to support named-pipe connections. Newer MySQL client software can open named pipe connections without any additional configuration; however, older client software may still require full access to open a named pipe connection. This variable sets the name of a Windows local group whose members are granted sufficient access by the MySQL server to use older named-pipe clients. As of MySQL 8.0.24, the default value is set to an empty string, which means that no Windows user is granted full access to the named pipe. A new Windows local group name (for example,  mysql_old_client_users ) can be created in Windows and then used to replace the default value when access is absolutely necessary. In this case, limit the membership of the group to as few users as possible, removing users from the group when their client software is upgraded. A non-member of the group who attempts to open a connection to MySQL with the older named-pipe client is denied access until a Windows administrator adds the user to the group. Newly added users must log out and log in again to join the group (required by Windows). Setting the value to  ’*everyone*’  provides a language-independent way of referring to the Everyone group on Windows. The Everyone group is not secure by default. Command-Line Format --named-pipe-full-access-group=value Introduced 8.0.14 System Variable named_pipe_full_access_group Scope Global Dynamic No SET_VAR  Hint Applies No Platform Specific Windows Type String Default Value empty string Valid Values empty string valid Windows local group name *everyone* Command-Line Format --net-buffer-length=# System Variable net_buffer_length Scope Global, Session Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 16384 Minimum Value 1024 Maximum Value 1048576 843