Streams downgrade
=================

The streams processing implies receiving feedback for each stream with status `in_progress`
(`stream statuses description <./streams_statuses.html>`_).

The Luna-Video-Manager periodically checks the last streams feedbacks receiving time and in case of feedback is not
received in required time, the stream status will be changed to `restart`
(that means an attempt to restart stream processing) and immediately to `pending` status to put stream in waiting line
(see `streams distribution <./streams_distribution.html>`_ for details).

The check of conditions that must execute stream downgrade executed as periodical background task
of `master instance <./master_instance.html>`_. The period of execution can be configured using
`LUNA_VIDEO_MANAGER_STREAM_STATUS_OBSOLETING_INTERVAL` setting. Streams will considered as outdated if last feedback
time was not received in time, which can be configured using `LUNA_VIDEO_MANAGER_STREAM_STATUS_OBSOLETING_PERIOD`
setting.
It is highly not recommended to change these values without understanding of consequences.

.. note:: Splittable streams downgrade works in the same way for each part of splittable stream as for not splittable stream.

Agents downgrade
================

The agents interaction assumes periodic requests to Luna-Video-Manager
(see `agent interaction chapter <./agent_interaction.html>`_ for details).

The Luna-Video-Manager periodically checks the last agent
`get streams for processing request <_static/api.html#operation/postAgentStreams>`_ time and if it was too late, set
agent status as `not_ready`, which means agent will be excluded from `streams distribution <./streams_distribution.html>`_ line.

If such agent will make `get streams for processing request <_static/api.html#operation/postAgentStreams>`_ later, it's
status will be updated to `ready` and agent will be added to list of agents that can process streams
(such behavior is needed to process possible network issues).

The check of conditions that must execute agent status downgrade executed as periodical background task
of `master instance <./master_instance.html>`_. The period of execution can be configured using
`LUNA_VIDEO_MANAGER_AGENT_STATUS_OBSOLETING_INTERVAL` setting. Agents will considered as `not_ready` if last
request from agent was not received in time, which can be configured using
`LUNA_VIDEO_MANAGER_AGENT_STATUS_OBSOLETING_PERIOD` setting.
It is highly not recommended to change these values without understanding of consequences.