Don't set explicit IDENTITY for clients

explicit IDENTITIES imply a potentially undesirable side-effect called 'durable sockets', which should be avoided.

IPython/parallel/client/client.py

@@ -466,7 +466,7 b' class Client(HasTraits):'
         self.session = Session(**extra_args)
 
         self._query_socket = self._context.socket(zmq.DEALER)
-        self._query_socket.setsockopt(zmq.IDENTITY, self.session.bsession)
+
         if self._ssh:
             tunnel.tunnel_connection(self._query_socket, url, sshserver, **ssh_kwargs)
         else:
@@ -607,29 +607,21 b' class Client(HasTraits):'
             ident = self.session.bsession
             if content.mux:
                 self._mux_socket = self._context.socket(zmq.DEALER)
-                self._mux_socket.setsockopt(zmq.IDENTITY, ident)
                 connect_socket(self._mux_socket, content.mux)
             if content.task:
                 self._task_scheme, task_addr = content.task
                 self._task_socket = self._context.socket(zmq.DEALER)
-                self._task_socket.setsockopt(zmq.IDENTITY, ident)
                 connect_socket(self._task_socket, task_addr)
             if content.notification:
                 self._notification_socket = self._context.socket(zmq.SUB)
                 connect_socket(self._notification_socket, content.notification)
                 self._notification_socket.setsockopt(zmq.SUBSCRIBE, b'')
-            # if content.query:
-            #     self._query_socket = self._context.socket(zmq.DEALER)
-            #     self._query_socket.setsockopt(zmq.IDENTITY, self.session.bsession)
-            #     connect_socket(self._query_socket, content.query)
             if content.control:
                 self._control_socket = self._context.socket(zmq.DEALER)
-                self._control_socket.setsockopt(zmq.IDENTITY, ident)
                 connect_socket(self._control_socket, content.control)
             if content.iopub:
                 self._iopub_socket = self._context.socket(zmq.SUB)
                 self._iopub_socket.setsockopt(zmq.SUBSCRIBE, b'')
-                self._iopub_socket.setsockopt(zmq.IDENTITY, ident)
                 connect_socket(self._iopub_socket, content.iopub)
             self._update_engines(dict(content.engines))
         else:

IPython/parallel/controller/hub.py

@@ -585,7 +585,7 b' class Hub(SessionFactory):'
         self.log.info("queue::client %r submitted request %r to %s", client_id, msg_id, eid)
         # Unicode in records
         record['engine_uuid'] = queue_id.decode('ascii')
-        record['client_uuid'] = client_id.decode('ascii')
+        record['client_uuid'] = msg['header']['session']
         record['queue'] = 'mux'
 
         try:
@@ -677,7 +677,7 b' class Hub(SessionFactory):'
             return
         record = init_record(msg)
 
-        record['client_uuid'] = client_id.decode('ascii')
+        record['client_uuid'] = msg['header']['session']
         record['queue'] = 'task'
         header = msg['header']
         msg_id = header['msg_id']
@@ -1205,6 +1205,7 b' class Hub(SessionFactory):'
                 self.db.add_record(msg_id, init_record(msg))
             except Exception:
                 self.log.error("db::DB Error updating record: %s", msg_id, exc_info=True)
+                return finish(error.wrap_exception())
 
         finish(dict(status='ok', resubmitted=resubmitted))