.. _tarantool-server-config:


``findface-tarantool-server``
---------------------------------

The ``findface-tarantool-server`` service provides interaction between the ``findface-sf-api`` service and the Tarantool-based biometric database in the following way:

.. tip::
   See `Tarantool official documentation <https://tarantool.io/en/>`_ for details.

* From ``findface-sf-api``, ``findface-tarantool-server`` receives data, such as information of detected in video faces, to write into the biometric database.
* By request from ``findface-sf-api``, ``findface-tarantool-server`` performs database searches and returns search results.

To increase search speed, multiple ``findface-tarantool-server`` shards can be created on each Tarantool host. Their running concurrently leads to a remarkable increase in performance (70x-100x).

Functionality:

* saving face data to the biometric database,
* database search,
* implementation of direct API requests to the database (see :ref:`tarantool-api`).

The ``findface-tarantool-server`` configuration is done through the ``/etc/tarantool/instances.available/<shard-*>.lua`` configuration file. In a cluster environment, configuration has to be done for each shard.

.. code::
 
   --
   -- Please, read the tarantool documentation at https://www.tarantool.io/en/doc/1.10/
   --

   box.cfg{
       -- THIS IS NOT HTTP API PORT, it's for admin operations
       listen = '127.0.0.1:32001',

       --Directory to store data
       vinyl_dir = '/opt/ntech/var/lib/tarantool/shard-001',
       work_dir = '/opt/ntech/var/lib/tarantool/shard-001',
       memtx_dir = '/opt/ntech/var/lib/tarantool/shard-001/snapshots',
       wal_dir = '/opt/ntech/var/lib/tarantool/shard-001/xlogs',

       --Maximum mem usage in bytes
       memtx_memory = 200 * 1024 * 1024,

       checkpoint_interval = 3600*4,
       checkpoint_count = 3,

       --uncomment only if you know what you are doing!!! and don't forget box.snapshot()
       -- wal_mode = 'none',
   
       --if true, tarantool tries to continue if there is an error while reading a snapshot/xlog files:  skips invalid records, reads as much data as possible and re-builds the file
       -- force_recovery = true,
   }

   pcall(function() box.schema.user.grant('guest', 'execute,read,write', 'universe') end)


   dofile("/etc/findface-security/tnt_schema.lua")


   -- host:port to bind, HTTP API
   FindFace = require("FindFace")
   FindFace.start("127.0.0.1", 8101, {
       license_ntls_server="127.0.0.1:3133",
       meta_indexes=meta_indexes,
       meta_scheme=meta_scheme
   })




When configuring ``findface-tarantool-server``, refer to the following parameters:

+--------------------------+----------------------------------------------------------------------------------------------------------+
| Parameter                | Description                                                                                              |
+==========================+==========================================================================================================+
| ``force_recovery``       | Enables automatic database recovery. In this case, each time an error occurs while reading a snapshot or |
|                          | xlog file, Tarantool will skip invalid records, read as much data as possible, and re-build the file.    |
+--------------------------+----------------------------------------------------------------------------------------------------------+
| ``license_ntls_server``  | IP address and port of the ``findface-ntls`` license server.                                             |
+--------------------------+----------------------------------------------------------------------------------------------------------+
| ``memtx_memory``         | Maximum RAM that can be used by a Tarantool shard. Set in bytes, depending on the number of faces the    |
|                          | shard handles. Consult our experts by support@ntechlab.com before setting this parameter.                |
+--------------------------+----------------------------------------------------------------------------------------------------------+
| ``meta_scheme``          | A database structure to store the face recognition results. The structure is created as a set of fields. |
|                          | Describe each field with the following parameters: ``id``: field id; ``name``: field name, must be the   |
|                          | same as the name of a relevant face parameter; ``field_type``: data type; ``default``: field default     |
|                          | value, if a default value exceeds ‘1e14 – 1', use a string data type to specify it, for example,         |
|                          | ``"123123.."`` instead of ``123123..``.                                                                  |                                                                           
+--------------------------+----------------------------------------------------------------------------------------------------------+

Default database structure is passed from ``/etc/findface-security/tnt_schema.lua`` to the ``meta_scheme`` parameter. See :ref:`modify-schema` for details.