.. _database_container:

********
Database
********

.. _database_creation:

Creation and Initialization
===========================

Starting from the Callisto version, the database on the **XiVO PBX** and **all mediaservers** is started inside a docker container based on custom image.
On first startup the database will be initialized and the required structure and data will be created inside a host mounted folder ``/var/lib/postgresql/11/main/``.

.. _database_configuration:

Custom database configuration
=============================

The database image contains a default postgres configuration and some specific defaults required by our application:

* the postgres default configuration is located in :file:`/var/lib/postgresql/11/main/postgresql.conf`
* and our custom defaults are in :file:`/var/lib/postgresql/11/main/conf.d/00-xivo-default.conf`.

.. warning:: Do not change these files!

If you need to change some parameters, create another file in :file:`/var/lib/postgresql/11/main/conf.d/` prefixed with a number like ``01`` or upper and with a ``.conf`` extension. This file will be loaded after all defaults and can override any parameter.

Sample configuration
--------------------

Here is an example to increase the default number of concurrent connection to the database:

:file:`/var/lib/postgresql/11/main/conf.d/10-custom-max-connection.conf`::

  max_connections = 300

Apply the configuration
-----------------------

Run this command to reload postgres configuration::

  xivo-dcomp reload-db

It will not restart db container despite the message *"Killing xivo_db_1"*.

Files path summary table
========================

+------------------------+-------------------------------------+-------------------------------------------------------------------------------------------------------+
| File                   | Path                                | Comment                                                                                               |
+========================+=====================================+=======================================================================================================+
| postgresql.conf        | /var/lib/postgresql/11/main/        | Please, do not edit this file but use overriding mechanism explained in :ref:`database_configuration` |
+------------------------+-------------------------------------+-------------------------------------------------------------------------------------------------------+
| conf.d files           | /var/lib/postgresql/11/main/conf.d/ | Files are handled in Lexicographical order                                                            |
+------------------------+-------------------------------------+-------------------------------------------------------------------------------------------------------+
| pg_hba.conf            | /var/lib/postgresql/11/main/        | Configure connection authorization in this file                                                       |
+------------------------+-------------------------------------+-------------------------------------------------------------------------------------------------------+
| postgresql-11-main.log | /var/log/postgresql/                | Database log file.                                                                                    |
+------------------------+-------------------------------------+-------------------------------------------------------------------------------------------------------+

.. _replication_schema:

Connections to database and replication schema
==============================================

This schema shows required database connections between different types of servers.
These connections must be authorized in ``pg_hba.conf`` file. It is being done automatically or it is described in installation or upgrade documentation.

It also shows how asterisk database is replicated. Only *configuration* tables are replicated between asterisk databases
and only *event* tables (cel and queue_log) are replicated to stats database.

.. figure:: images/db_connections.png
   :scale: 100%