Cluster definition
==================

A cluster consists of **a server**, referred to as the **Manager**, and multiple embedded devices connected to this server, known as **Nodes**.

.. image:: ../_static/images/light-cluster.png
    :alt: Task
    :align: center
    :class: only-light

.. image:: ../_static/images/dark-cluster.png
    :alt: Task
    :align: center
    :class: only-dark


Initialization of a cluster
---------------------------

1. Some dependencies must be installed and started in order to start a cluster :

- :code:`mosquitto` for :code:`manta_manager` and :code:`manta_node` communications as a message broker. It should be installed on the same machine where :code:`manta_manager` is deployed.
- :code:`mongodb` for :code:`manta_manager` for accessing database
- :code:`docker` for :code:`manta_node` for deploying tasks in isolated environments

2. On server machine, :code:`manta_manager` must be started before :code:`manta_node` by following the :doc:`unsecured mode deployment<../deployment/unsecured>` or :doc:`secured mode deployment<../deployment/secured>`.

3. :code:`manta_node` are executed on embedded devices to finalize the cluster.