voltha unable to save device after some time

20190104T185427.843 DEBUG MainThread local_handler.ListReachableLogicalDevices {'instance_id': 'vcore-0_1546623561', 'vcore_id': '0001', 'request': , 'event': 'grpc-request'} 20190104T185427.845 ERROR ThreadPoolExecutor-0_3 grpc_utils.in_thread_wrapper {'exception': 'Traceback (most recent call last):\n File "/voltha/common/utils/grpc_utils.py", line 100, in in_thread_wrapper\n result = f.result()\n File "/usr/local/lib/python2.7/dist-packages/concurrent/futures/_base.py", line 462, in result\n return self.__get_result()\n File "/usr/local/lib/python2.7/dist-packages/concurrent/futures/_base.py", line 414, in __get_result\n raise exception_type, self._exception, self._traceback\nKeyError: \'key id=00011afbec830d0a not found\'', 'e': KeyError('key id=00011afbec830d0a not found',), 'vcore_id': '0001', 'args': (<voltha.core.local_handler.LocalHandler object at 0x7f9b959e1f50>, , <grpc._server._Context object at 0x7f9b1034d550>), 'instance_id': 'vcore-0_1546623561', 'kw': {}, 'func': <function ListReachableLogicalDevices at 0x7f9b8fcba2a8>} 20190104T185427.846 ERROR ThreadPoolExecutor-0_3 _server._call_behavior Exception calling application: 'key id=00011afbec830d0a not found' Traceback (most recent call last): File "/usr/local/lib/python2.7/dist-packages/grpc/_server.py", line 390, in _call_behavior return behavior(argument, context), True File "/voltha/common/utils/grpc_utils.py", line 100, in in_thread_wrapper result = f.result() File "/usr/local/lib/python2.7/dist-packages/concurrent/futures/_base.py", line 462, in result return self.__get_result() File "/usr/local/lib/python2.7/dist-packages/concurrent/futures/_base.py", line 414, in __get_result raise exception_type, self._exception, self._traceback KeyError: 'key id=00011afbec830d0a not found'

(logical device 000100000ac004ce) devices(logical device 000100000ac004ce) devicesDevices:+------------------+---------+------+-------------+-------------+----------------+-------------------+|               id |    type | root | admin_state | oper_status | connect_status |     host_and_port |+------------------+---------+------+-------------+-------------+----------------+-------------------+| 00011afbec830d0a | openolt | True |     ENABLED |  ACTIVATING |    UNREACHABLE | 10.192.4.206:9191 |+------------------+---------+------+-------------+-------------+----------------+-------------------+(logical device 000100000ac004ce) portsLogical device ports:table empty(logical device 000100000ac004ce) \(logical device 000100000ac004ce)(logical device 000100000ac004ce) portsLogical device ports:table empty(logical device 000100000ac004ce) devicesEXCEPTION of type '_Rendezvous' occured with message: '<_Rendezvous of RPC that terminated with: status = StatusCode.NOT_FOUND details = "Device '00011afbec830d0a' not found" debug_error_string = "{"created":"@1546628041.702371510","description":"Error received from peer","file":"src/core/lib/surface/call.cc","file_line":1017,"grpc_message":"Device '00011afbec830d0a' not found","grpc_status":5}"