.. _video-allocation:

Allocate ``video-worker`` to Video Stream Source
======================================================

In a distributed architecture, it is often necessary that video streams be processed *in situ*, without being redistributed across remote ``video-worker`` instances by the principal server.

.. note::
   Among typical use cases are hotel chains, chain stores, several security checkpoints in the same building, etc.

In this case, allocate the local ``video-worker`` to the video stream source.

There are two ways to specify allocation labels:

* by ``video-worker.yaml`` configuration file
* by environment variable or flag.

.. note::

   Use the same name of labels in the ``video-worker`` configuration file and in the video processing job, otherwise video stream source will not process.

Do the following:

#. Open the ``/opt/ffserver/configs/video-worker.yaml`` configuration file and specify the allocation labels in the dictionary format (label ``district`` in the example below).

   .. code::

      sudo vi /opt/ffserver/configs/video-worker.yaml

      labels: {"district": "SVAO"}

#. As an alternative way, you can use environment variable ``CFG_LABELS`` or ``--labels`` flag when running ``video-worker`` with docker run command:

   .. code::

      CFG_LABELS=district=SVAO

#. Create a :ref:`video processing job <video-methods>` with labels.

   .. code::

      "labels": {
            "district": "SVAO"
          },


.. note::
   If a video stream source is assigned an allocation label, its video stream can be processed by a ``video-worker`` instance with the same label, as well as by all unlabeled ``video-worker`` instances.

.. warning::
   If a labeled video stream source is processed by an unlabeled ``video-worker`` instance and a free similar-labeled instance appears, the video stream source won't automatically switch to the latter. Restart the similar-labeled video stream source.