.. _guide_session:

Session
=======

Overview
---------

A session manages state about a particular configuration. By default, a session is created for you when needed. However, it's possible and recommended that in some scenarios you maintain your own session. Sessions typically store the following:

* Credentials
* AWS Region
* Other configurations related to your profile


Default session
----------------

Boto3 acts as a proxy to the default session. This is created automatically when you create a low-level client or resource client::

    import boto3

    # Using the default session
    sqs = boto3.client('sqs')
    s3 = boto3.resource('s3')


Custom session
---------------

You can also manage your own session and create low-level clients or resource clients from it::


    import boto3
    import boto3.session

    # Create your own session
    my_session = boto3.session.Session()

    # Now we can create low-level clients or resource clients from our custom session
    sqs = my_session.client('sqs')
    s3 = my_session.resource('s3')


Session configurations
------------------------

You can configure each session with specific credentials, AWS Region information, or profiles. The most common configurations you might use are:

* ``aws_access_key_id`` - A specific AWS access key ID.
* ``aws_secret_access_key`` - A specific AWS secret access key.
* ``region_name`` - The AWS Region where you want to create new connections.
* ``profile_name`` - The profile to use when creating your session.


.. note::
    Only set the ``profile_name`` parameter when a specific profile is required for your session. To use the default profile, don’t set the ``profile_name`` parameter at all. If the ``profile_name`` parameter isn't set *and* there is no default profile, an empty config dictionary will be used.

    For a detailed list of per-session configurations, see the `Session core reference <https://boto3.amazonaws.com/v1/documentation/api/latest/reference/core/session.html>`_.


Multithreading or multiprocessing with sessions
-----------------------------------------------

Similar to ``Resource`` objects, ``Session`` objects are not thread safe
and should not be shared across threads and processes. It's recommended
to create a new ``Session`` object for each thread or process::

    import boto3
    import boto3.session
    import threading

    class MyTask(threading.Thread):
        def run(self):
            # Here we create a new session per thread
            session = boto3.session.Session()

            # Next, we create a resource client using our thread's session object
            s3 = session.resource('s3')

            # Put your thread-safe code here