[tune] Introduce ability to turn off default logging.

doc/source/tune-usage.rst

@@ -424,6 +424,9 @@ via the Experiment object as follows:
 
 These loggers will be called along with the default Tune loggers. All loggers must inherit the `Logger interface <tune-package-ref.html#ray.tune.logger.Logger>`__.
 
+Tune has default loggers for Tensorboard, CSV, and JSON formats. To turn these off, set
+``use_default_loggers=False`` in the ``Experiment`` initializer.
+
 You can also check out `logger.py <https://github.com/ray-project/ray/blob/master/python/ray/tune/logger.py>`__ for implementation details.
 
 An example can be found in `logging_example.py <https://github.com/ray-project/ray/blob/master/python/ray/tune/examples/logging_example.py>`__.

python/ray/tune/config_parser.py

@@ -87,6 +87,11 @@ def make_parser(parser_creator=None, **kwargs):
         help="Function for syncing the local_dir to upload_dir. If string, "
         "then it must be a string template for syncer to run and needs to "
         "include replacement fields '{local_dir}' and '{remote_dir}'.")
+    parser.add_argument(
+        "--use-default-loggers",
+        default=False,
+        type=bool,
+        help="Whether to use Tune's default loggers.")
     parser.add_argument(
         "--custom-loggers",
         default=None,
@@ -192,6 +197,7 @@ def create_trial_from_spec(spec, output_path, parser, **trial_kwargs):
         restore_path=spec.get("restore"),
         upload_dir=args.upload_dir,
         trial_name_creator=spec.get("trial_name_creator"),
+        use_default_loggers=args.use_default_loggers,
         custom_loggers=spec.get("custom_loggers"),
         # str(None) doesn't create None
         sync_function=spec.get("sync_function"),

python/ray/tune/examples/logging_example.py

@@ -66,6 +66,7 @@ def _restore(self, checkpoint_path):
         run=MyTrainableClass,
         num_samples=1,
         trial_name_creator=tune.function(trial_str_creator),
+        use_default_loggers=False,
         custom_loggers=[TestLogger],
         stop={"training_iteration": 1 if args.smoke_test else 99999},
         config={

python/ray/tune/experiment.py

@@ -62,6 +62,7 @@ class Experiment(object):
             to (e.g. ``s3://bucket``).
         trial_name_creator (func): Optional function for generating
             the trial string representation.
+        use_default_loggers (bool): Whether to use Tune's default loggers.
         custom_loggers (list): List of custom logger creators to be used with
             each Trial. See `ray/tune/logger.py`.
         sync_function (func|str): Function for syncing the local_dir to
@@ -117,6 +118,7 @@ def __init__(self,
                  local_dir=None,
                  upload_dir=None,
                  trial_name_creator=None,
+                 use_default_loggers=True,
                  custom_loggers=None,
                  sync_function=None,
                  checkpoint_freq=0,
@@ -145,6 +147,7 @@ def __init__(self,
             "local_dir": os.path.expanduser(local_dir or DEFAULT_RESULTS_DIR),
             "upload_dir": upload_dir or "",  # argparse converts None to "null"
             "trial_name_creator": trial_name_creator,
+            "use_default_loggers": use_default_loggers,
             "custom_loggers": custom_loggers,
             "sync_function": sync_function,
             "checkpoint_freq": checkpoint_freq,

python/ray/tune/logger.py

@@ -75,6 +75,7 @@ class UnifiedLogger(Logger):
         config: Configuration passed to all logger creators.
         logdir: Directory for all logger creators to log to.
         upload_uri (str): Optional URI where the logdir is sync'ed to.
+        use_default_loggers (bool): Whether to use Tune's default loggers.
         custom_loggers (list): List of custom logger creators.
         sync_function (func|str): Optional function for syncer to run.
             See ray/python/ray/tune/log_sync.py
@@ -84,9 +85,12 @@ def __init__(self,
                  config,
                  logdir,
                  upload_uri=None,
+                 use_default_loggers=True,
                  custom_loggers=None,
                  sync_function=None):
-        self._logger_list = [_JsonLogger, _TFLogger, _CSVLogger]
+        self._logger_list = []
+        if use_default_loggers:
+            self._logger_list += [_JsonLogger, _TFLogger, _CSVLogger]
         self._sync_function = sync_function
         self._log_syncer = None
         if custom_loggers:

python/ray/tune/test/trial_runner_test.py

@@ -793,10 +793,13 @@ def on_result(self, result):
                 "stop": {
                     "training_iteration": 1
                 },
+                "use_default_loggers": False,
                 "custom_loggers": [CustomLogger]
             }
         })
         self.assertTrue(os.path.exists(os.path.join(trial.logdir, "test.log")))
+        self.assertFalse(
+            os.path.exists(os.path.join(trial.logdir, "params.json")))
 
     def testCustomTrialString(self):
         [trial] = run_experiments({

python/ray/tune/trial.py

@@ -254,6 +254,7 @@ def __init__(self,
                  restore_path=None,
                  upload_dir=None,
                  trial_name_creator=None,
+                 use_default_loggers=True,
                  custom_loggers=None,
                  sync_function=None,
                  max_failures=0):
@@ -274,6 +275,7 @@ def __init__(self,
             or self._get_trainable_cls().default_resource_request(self.config))
         self.stopping_criterion = stopping_criterion or {}
         self.upload_dir = upload_dir
+        self.use_default_loggers = use_default_loggers
         self.custom_loggers = custom_loggers
         self.sync_function = sync_function
         validate_sync_function(sync_function)
@@ -331,6 +333,7 @@ def init_logger(self):
                 self.config,
                 self.logdir,
                 upload_uri=self.upload_dir,
+                use_default_loggers=self.use_default_loggers,
                 custom_loggers=self.custom_loggers,
                 sync_function=self.sync_function)
 
@@ -507,6 +510,7 @@ def __getstate__(self):
         state = self.__dict__.copy()
         state["resources"] = resources_to_json(self.resources)
 
+        # These are non-pickleable entries.
         pickle_data = {
             "_checkpoint": self._checkpoint,
             "config": self.config,