docs and bug fixed

docs/advanced/task_management.rst

@@ -1,4 +1,4 @@
-.. _task_managment:
+.. _task_management:
 
 =================================
 Task Management
@@ -10,15 +10,17 @@ Introduction
 =============
 
 The `Workflow <../component/introduction.html>`_ part introduces how to run research workflow in a loosely-coupled way. But it can only execute one ``task`` when you use ``qrun``.
-To automatically generate and execute different tasks, ``Task Management`` provides a whole process including `Task Generating`_, `Task Storing`_, `Task Running`_ and `Task Collecting`_. 
+To automatically generate and execute different tasks, ``Task Management`` provides a whole process including `Task Generating`_, `Task Storing`_, `Task Training`_ and `Task Collecting`_. 
 With this module, users can run their ``task`` automatically at different periods, in different losses, or even by different models.
 
-An example of the entire process is shown `here <https://github.com/microsoft/qlib/tree/main/examples/taskmanager/task_manager_rolling.py>`_.
+This whole process can be used in `Online Serving <../component/online.html>`_.
+
+An example of the entire process is shown `here <https://github.com/microsoft/qlib/tree/main/examples/model_rolling/task_manager_rolling.py>`_.
 
 Task Generating
 ===============
 A ``task`` consists of `Model`, `Dataset`, `Record` or anything added by users. 
-The specific task template(/definition/config) can be viewed in 
+The specific task template can be viewed in 
 `Task Section <../component/workflow.html#task-section>`_.
 Even though the task template is fixed, users can customize their ``TaskGen`` to generate different ``task`` by task template.
 
@@ -27,15 +29,16 @@ Here is the base class of ``TaskGen``:
 .. autoclass:: qlib.workflow.task.gen.TaskGen
     :members:
 
-``Qlib`` provider a class `RollingGen <https://github.com/microsoft/qlib/tree/main/qlib/workflow/task/gen.py>`_ to generate a list of ``task`` of the dataset in different date segments.
-This class allows users to verify the effect of data from different periods on the model in one experiment.
+``Qlib`` provides a class `RollingGen <https://github.com/microsoft/qlib/tree/main/qlib/workflow/task/gen.py>`_ to generate a list of ``task`` of the dataset in different date segments.
+This class allows users to verify the effect of data from different periods on the model in one experiment. More information in `here <../reference/api.html#TaskGen>`_.
 
 Task Storing
 ===============
 To achieve higher efficiency and the possibility of cluster operation, ``Task Manager`` will store all tasks in `MongoDB <https://www.mongodb.com/>`_.
+``TaskManager`` can fetch undone tasks automatically and manage the lifecycle of a set of tasks with error handling.
 Users **MUST** finished the configuration of `MongoDB <https://www.mongodb.com/>`_ when using this module.
 
-Users need to provide the URL and database name of ``task`` storing like this.
+Users need to provide the MongoDB URL and database name for using ``TaskManager`` in `initialization <../start/initialization.html#Parameters>`_ or make statement like this.
 
     .. code-block:: python
 
@@ -45,13 +48,12 @@ Users need to provide the URL and database name of ``task`` storing like this.
             "task_db_name" : "rolling_db" # database name
         }
 
-The CRUD methods of ``task`` can be found in TaskManager. 
-More methods can be seen in the `Github <https://github.com/microsoft/qlib/tree/main/qlib/workflow/task/manage.py>`_.
-
 .. autoclass:: qlib.workflow.task.manage.TaskManager
     :members:
 
-Task Running
+More information of ``Task Manager`` can be found in `here <../reference/api.html#TaskManager>`_.
+
+Task Training
 ===============
 After generating and storing those ``task``, it's time to run the ``task`` which are in the *WAITING* status.
 ``Qlib`` provides a method called ``run_task`` to run those ``task`` in task pool, however, users can also customize how tasks are executed.
@@ -60,14 +62,24 @@ It will run the whole workflow defined by ``task``, which includes *Model*, *Dat
 
 .. autofunction:: qlib.workflow.task.manage.run_task
 
+Meanwhile, ``Qlib`` provides a module called ``Trainer``. 
+``Trainer`` will train a list of tasks and return a list of model recorder.
+``Qlib`` offer two kind of Trainer, TrainerR is the simplest way and TrainerRM is based on TaskManager to help manager tasks lifecycle automatically. 
+If you do not want to use ``Task Manager`` to manage tasks, then use TrainerR to train a list of tasks generated by ``TaskGen`` is enough.
+More information is in `here <../reference/api.html#Trainer>`_.
+
 Task Collecting
 ===============
-To see the results of ``task`` after running or to update something, ``Qlib`` provides a ``TaskCollector`` to collect the tasks by filter condition (optional).
-Here are some methods in this class.
+To collect the results of ``task`` after training, ``Qlib`` provides `Collector <../reference/api.html#Collector>`_, `Group <../reference/api.html#Group>`_ and `Ensemble <../reference/api.html#Ensemble>`_ to collect the results in a readable, expandable and loosely-coupled way.
 
-.. autoclass:: qlib.workflow.task.collect.TaskCollector
-    :members:
+`Collector <../reference/api.html#Collector>`_ can collect object from everywhere and process them such as merging, grouping, averaging and so on. It has 2 step action including ``collect`` (collect anything in a dict) and ``process_collect`` (process collected dict).
 
-``Qlib`` provides a concrete `example <https://github.com/microsoft/qlib/tree/main/examples/taskmanager/task_manager_rolling_with_updating.py>`_, including a whole process of `Task Generating`_ (using `RollingGen <https://github.com/microsoft/qlib/tree/main/qlib/workflow/task/gen.py>`_), `Task Storing`_, `Task Running`_ and `Task Collecting`_.
-Besides, the `example <https://github.com/microsoft/qlib/tree/main/examples/taskmanager/task_manager_rolling_with_updating.py>`_ uses a ``ModelUpdater`` inherited from ``TaskCollector``, which can update the inferences and retrain the model if it is out of date.
-Actually, the model updating can be viewed as a subset of ``Online Serving``.
+`Group <../reference/api.html#Group>`_ also has 2 steps including ``group`` (can group a set of object based on `group_func` and change them to a dict) and ``reduce`` (can make a dict become an ensemble based on some rule).
+For example: {(A,B,C1): object, (A,B,C2): object} ---``group``---> {(A,B): {C1: object, C2: object}} ---``reduce``---> {(A,B): object}
+
+`Ensemble <../reference/api.html#Ensemble>`_ can merge the objects in an ensemble. 
+For example: {C1: object, C2: object} ---``Ensemble``---> object
+
+So the hierarchy is ``Collector``'s second step correspond to ``Group``. And ``Group``'s second step correspond to ``Ensemble``.
+
+For more information, please see `Collector <../reference/api.html#Collector>`_, `Group <../reference/api.html#Group>`_ and `Ensemble <../reference/api.html#Ensemble>`_, or the `example <https://github.com/microsoft/qlib/tree/main/examples/model_rolling/task_manager_rolling.py>`_