get default logger from Application.instance()

IPython/parallel/apps/launcher.py

@@ -49,6 +49,7 b' except ImportError:'
 
 from zmq.eventloop import ioloop
 
+from IPython.config.application import Application
 from IPython.config.configurable import Configurable
 from IPython.utils.text import EvalFormatter
 from IPython.utils.traitlets import Any, Int, List, Unicode, Dict, Instance
@@ -107,7 +108,9 b' class BaseLauncher(Configurable):'
     # the work_dir option.
     work_dir = Unicode(u'.')
     loop = Instance('zmq.eventloop.ioloop.IOLoop')
-    log = Instance('logging.Logger', ('root',))
+    log = Instance('logging.Logger')
+    def _log_default(self):
+        return Application.instance().log
     
     start_data = Any()
     stop_data = Any()

IPython/parallel/apps/logwatcher.py

@@ -19,6 +19,7 b' import sys'
 import zmq
 from zmq.eventloop import ioloop, zmqstream
 
+from IPython.config.application import Application
 from IPython.config.configurable import Configurable
 from IPython.utils.traitlets import Int, Unicode, Instance, List
 
@@ -34,7 +35,9 b' class LogWatcher(Configurable):'
     This can subscribe to multiple topics, but defaults to all topics.
     """
     
-    log = Instance('logging.Logger', ('root',))
+    log = Instance('logging.Logger')
+    def _log_default(self):
+        return Application.instance().log
     
     # configurables
     topics = List([''], config=True,

IPython/parallel/controller/dictdb.py

@@ -44,6 +44,7 b' We support a subset of mongodb operators:'
 
 from datetime import datetime
 
+from IPython.config.application import Application
 from IPython.config.configurable import Configurable
 
 from IPython.utils.traitlets import Dict, Unicode, Instance
@@ -83,7 +84,9 b' class BaseDB(Configurable):'
     """Empty Parent class so traitlets work on DB."""
     # base configurable traits:
     session = Unicode("")
-    log = Instance('logging.Logger', ('root',))
+    log = Instance('logging.Logger')
+    def _log_default(self):
+        return Application.instance().log
 
 class DictDB(BaseDB):
     """Basic in-memory dict-based object for saving Task Records.

IPython/parallel/controller/heartmonitor.py

@@ -18,6 +18,7 b' import zmq'
 from zmq.devices import ThreadDevice
 from zmq.eventloop import ioloop, zmqstream
 
+from IPython.config.application import Application
 from IPython.config.configurable import Configurable
 from IPython.utils.traitlets import Set, Instance, CFloat
 
@@ -58,7 +59,10 b' class HeartMonitor(Configurable):'
         ' (in ms) [default: 100]',
     )
     
-    log = Instance('logging.Logger', ('root',))
+    log = Instance('logging.Logger')
+    def _log_default(self):
+        return Application.instance().log
+    
     pingstream=Instance('zmq.eventloop.zmqstream.ZMQStream')
     pongstream=Instance('zmq.eventloop.zmqstream.ZMQStream')
     loop = Instance('zmq.eventloop.ioloop.IOLoop')

IPython/zmq/session.py

@@ -31,6 +31,7 b' from zmq.utils import jsonapi'
 from zmq.eventloop.ioloop import IOLoop
 from zmq.eventloop.zmqstream import ZMQStream
 
+from IPython.config.application import Application
 from IPython.config.configurable import Configurable
 from IPython.utils.importstring import import_item
 from IPython.utils.jsonutil import extract_dates, squash_dates, date_default
@@ -79,7 +80,9 b' class SessionFactory(Configurable):'
     and IOLoop.
     """
     
-    log = Instance('logging.Logger', ('', logging.WARN))
+    log = Instance('logging.Logger')
+    def _log_default(self):
+        return Application.instance().log
     
     logname = Unicode('')
     def _logname_changed(self, name, old, new):