Update flightrec topic

* Add flightrec reference section (YAML)
* Update Flight Recorder page

Author: xuniq

doc/code_snippets/snippets/config/instances.enabled/flightrec/config.yaml

@@ -0,0 +1,11 @@
+groups:
+  group001:
+    replicasets:
+      replicaset001:
+        instances:
+          instance001:
+            iproto:
+              listen:
+              - uri: '127.0.0.1:3301'
+              flightrec:
+                enabled: true

doc/code_snippets/snippets/config/instances.enabled/flightrec/instances.yml

@@ -0,0 +1 @@
+instance001:

doc/enterprise/flight_recorder.rst

@@ -3,36 +3,40 @@
 Flight recorder
 ===============
 
+**Example on GitHub**: `flightrec <https://github.com/tarantool/doc/tree/latest/doc/code_snippets/snippets/config/instances.enabled/flightrec>`_
+
 The flight recorder available in the Enterprise Edition is an event collection tool that
 gathers various information about a working Tarantool instance, such as:
 
 *   logs
-
 *   metrics
-
 *   requests and responses
 
 This information helps you investigate incidents related
 to :ref:`crashing <admin-disaster_recovery>` a Tarantool instance.
 
 
-.. _enable:
+.. _enterprise-flight-recorder_enable:
 
 Enabling the flight recorder
 ----------------------------
 
 The flight recorder is disabled by default and can be enabled and configured for
 a specific Tarantool instance.
-To enable the flight recorder, set the ``flightrec_enabled``
-:doc:`configuration option </reference/configuration/index>` to ``true``.
-This option is :ref:`dynamic <box_cfg_params>` and can be changed at runtime by calling ``box.cfg{}``:
+To enable the flight recorder, set the :ref:`flightrec.enabled <configuration_reference_flightrec_enabled>`
+configuration option to ``true``. This option is dynamic and can be changed at runtime.
 
-.. code-block:: lua
+..  literalinclude:: /code_snippets/snippets/replication/instances.enabled/flightrec/config.yaml
+    :language: yaml
+    :start-at: flightrec:
+    :end-at: enabled: true
+    :dedent:
 
-    box.cfg{ flightrec_enabled = true }
 
 After ``flightrec_enabled`` is set to ``true``, the flight recorder starts collecting data in the flight recording file  ``current.ttfr``.
 This file is stored in the :ref:`memtx_dir <cfg_basic-memtx_dir>` directory.
+By default, the directory is ``var/log/{{ instance_name }}/<file_name>.ttfr``.
+
 If the instance crashes and reboots, Tarantool rotates the flight recording:
 ``current.ttfr`` is renamed to ``<timestamp>.ttfr`` (for example, ``20230411T050721.ttfr``)
 and the new ``current.ttfr`` file is created for collecting data.
@@ -44,175 +48,16 @@ Tarantool continues writing to the existing ``current.ttfr`` file after restart.
     Note that old flight recordings should be removed manually.
 
 
+See also: :ref:`Flight recorder configuration options <configuration_reference_flightrec>`.
 
-.. _config:
-
-Configuration
--------------
-
-This section describes options related to the flight recorder configuration.
-Note that all options are :ref:`dynamic <box_cfg_params>` and can be changed at runtime.
-
-.. TODO not implemented yet
-    .. _config-directory:
-
-    Flight recording directory
-    ~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-    .. _cfg_flightrec_dir:
-
-    .. confval:: flightrec_dir
-
-        Specifies the directory used to store flight recordings (``*.ttfr`` files).
-
-        | Type: string
-        | Default: :ref:`memtx_dir <cfg_basic-memtx_dir>`
-        | Environment variable: TT_FLIGHTREC_DIR
-
-
-
-.. _config-logs:
-
-Logs
-~~~~
-
-This section describes the flight recorder settings related to :ref:`logging <cfg_logging-log>`.
-For example, you can configure a more detailed logging level in the flight recorder for deeper analysis.
-
-* :ref:`flightrec_logs_size <cfg_flightrec_logs_size>`
-* :ref:`flightrec_logs_max_msg_size <cfg_flightrec_logs_max_msg_size>`
-* :ref:`flightrec_logs_log_level <cfg_flightrec_logs_log_level>`
-
-.. _cfg_flightrec_logs_size:
-
-.. confval:: flightrec_logs_size
-
-    Specifies the size (in bytes) of the log storage.
-    You can set this option to ``0`` to disable the log storage.
-
-    | Type: integer
-    | Default: 10485760
-    | Environment variable: TT_FLIGHTREC_LOGS_SIZE
-
-
-.. _cfg_flightrec_logs_max_msg_size:
-
-.. confval:: flightrec_logs_max_msg_size
-
-    Specifies the maximum size (in bytes) of the log message.
-    The log message is truncated if its size exceeds this limit.
-
-    | Type: integer
-    | Default: 4096
-    | Maximum: 16384
-    | Environment variable: TT_FLIGHTREC_LOGS_MAX_MSG_SIZE
-
-
-.. _cfg_flightrec_logs_log_level:
-
-.. confval:: flightrec_logs_log_level
-
-    Specifies the level of detail the log has.
-    You can learn more about log levels from the :ref:`log_level <cfg_logging-log_level>`
-    option description.
-    Note that the ``flightrec_logs_log_level`` value might differ from ``log_level``.
-
-    | Type: integer
-    | Default: 6
-    | Environment variable: TT_FLIGHTREC_LOGS_LOG_LEVEL
-
-
-.. _config-metrics:
-
-Metrics
-~~~~~~~
-
-This section describes the flight recorder settings related to collecting
-:ref:`metrics <metrics-reference>`.
-
-* :ref:`flightrec_metrics_period <cfg_flightrec_metrics_period>`
-* :ref:`flightrec_metrics_interval <cfg_flightrec_metrics_interval>`
-
-.. _cfg_flightrec_metrics_period:
-
-.. confval:: flightrec_metrics_period
-
-    Specifies the time period (in seconds) that defines how long metrics are stored from the moment of dump.
-    So, this value defines how much historical metrics data is collected up to the moment of crash.
-    The frequency of metric dumps is defined by :ref:`flightrec_metrics_interval <cfg_flightrec_metrics_interval>`.
-
-    | Type: integer
-    | Default: 180
-    | Environment variable: TT_FLIGHTREC_METRICS_PERIOD
-
-
-.. _cfg_flightrec_metrics_interval:
-
-.. confval:: flightrec_metrics_interval
-
-    Specifies the time interval (in seconds) that defines the frequency of dumping metrics.
-    This value shouldn't exceed :ref:`flightrec_metrics_period <cfg_flightrec_metrics_period>`.
-
-    | Type: number
-    | Default: 1.0
-    | Minimum: 0.001
-    | Environment variable: TT_FLIGHTREC_METRICS_INTERVAL
-
-.. NOTE::
-
-    Given that the average size of a metrics entry is 2 kB,
-    you can estimate the size of the metrics storage as follows:
-
-    .. code-block:: console
-
-        (flightrec_metrics_period / flightrec_metrics_interval) * 2 kB
-
-
-
-.. _config-requests:
-
-Requests
-~~~~~~~~
-
-This section lists the flight recorder settings related to
-storing the :ref:`request and response <internals-requests_responses>` data.
-
-* :ref:`flightrec_requests_size <cfg_flightrec_requests_size>`
-* :ref:`flightrec_requests_max_req_size <cfg_flightrec_requests_max_req_size>`
-* :ref:`flightrec_requests_max_res_size <cfg_flightrec_requests_max_res_size>`
-
-.. _cfg_flightrec_requests_size:
-
-.. confval:: flightrec_requests_size
-
-    Specifies the size (in bytes) of storage for the request and response data.
-    You can set this parameter to ``0`` to disable a storage of requests and responses.
-
-    | Type: integer
-    | Default: 10485760
-    | Environment variable: TT_FLIGHTREC_REQUESTS_SIZE
-
-
-
-.. _cfg_flightrec_requests_max_req_size:
-
-.. confval:: flightrec_requests_max_req_size
-
-    Specifies the maximum size (in bytes) of a request entry.
-    A request entry is truncated if this size is exceeded.
-
-    | Type: integer
-    | Default: 16384
-    | Environment variable: TT_FLIGHTREC_REQUESTS_MAX_REQ_SIZE
-
+Reading flight recordings
+-------------------------
 
-.. _cfg_flightrec_requests_max_res_size:
+Since:** :doc:`3.0.0 </release/3.0.0>` version, you can read flight recordings using the API provided by the
+``flightrec`` module. To open and read ``*.ttfr`` files, use the Lua API:
 
-.. confval:: flightrec_requests_max_res_size
+..  include:: /release/3.0.0.rst
+    :start-after: 3-0-flight-recorder-begin
+    :end-before: 3-0-flight-recorder-end
 
-    Specifies the maximum size (in bytes) of a response entry.
-    A response entry is truncated if this size is exceeded.
 
-    | Type: integer
-    | Default: 16384
-    | Environment variable: TT_FLIGHTREC_REQUESTS_MAX_RES_SIZE