ArangoDB integrator

This module uses ArangoDB as data storage for different services.

Features

Feature	status
Cache backend	✅ POC ready
Queue core	✅ POC ready
Queue advanced	✅ POC ready
Logger	✅ POC ready
Lock	✅ POC ready
Flood	✅ POC ready
KeyValue	✅ POC ready
State	See KeyValue
Session	not yet
[SearchAPI server]	not yet
Config entity storage	not yet
Content entity storage	not yet
Full database driver	not yet

How to setup ArangoDB connections

One or more connection can be defined. Usually the endpoint and/or the database is the difference between these connections.

This parameter is used by the arangodb.connection_factory service.

DRUPAL_ROOT/sites/*/services.arangodb.yml

parameters:
  arangodb.connection_options:
    default:
      endpoint: 'tcp://127.0.0.1:8529'
      Connection: 'Close'
      timeout: 3
      Reconnect: true
      policy: 'last'
      createCollection: false
      AuthType: 'Basic'
      AuthUser: 'me'
      AuthPasswd: 'mySecret01'
      database: 'cache'

Connection credentials (username/password) also can be defined as service parameters, but easier to manage them in the settings.local.php. See below. Connection options defined in settings.local.php have a higher priority over the ones defined in services.*.yml#/parameters/arangodb.connection_options.

DRUPAL_ROOT/sites/*/settings.local.php

use ArangoDBClient\ConnectionOptions as ArangoDbConnectionOptions;
use ArangoDBClient\DefaultValues as ArangoDbDefaultValues;

$settings['arangodb.connection_options'] = [
  'default' => [
    ArangoDbConnectionOptions::OPTION_ENDPOINT => getenv('APP_ARANGODB_CONNECTION_DEFAULT_ENDPOINT') ?: 'tcp://127.0.0.1:8529',
    ArangoDbConnectionOptions::OPTION_AUTH_TYPE => ArangoDbDefaultValues::DEFAULT_AUTH_TYPE,
    ArangoDbConnectionOptions::OPTION_AUTH_USER => getenv('APP_ARANGODB_CONNECTION_DEFAULT_USER') ?: getenv('USER'),
    ArangoDbConnectionOptions::OPTION_AUTH_PASSWD => getenv('APP_ARANGODB_CONNECTION_DEFAULT_PASSWD') ?: 'admin',
    ArangoDbConnectionOptions::OPTION_DATABASE => getenv('APP_ARANGODB_CONNECTION_DEFAULT_DATABASE') ?: $databases['default']['default']['database'],
  ],
];

Feature - Cache backend

Remaining tasks:

1. tests
2. documentation

settings.local.php

$settings['cache']['default'] = 'cache.backend.arangodb_default';
$settings['cache']['bins']['config'] = 'cache.backend.arangodb_no_serializer';

Feature - Queue core

Remaining tasks:

1. tests
2. documentation

settings.local.php

$settings['queue_default'] = 'arangodb.queue_core.storage.shared';
$settings['queue_reliable_service_foo'] = 'arangodb.queue_core.storage.dedicated';
//$settings['queue_service_bar'] = 'arangodb.queue_core.storage.dedicated';

Feature - Queue advanced

The integration is done by implementing an AdvancedQueue/Backend plugin.

Feature - Logger

Logger in the arangodb module isn't activated by default. In order to activate the logger, the following line has to be added to the settings.local.php.

settings.local.php

$settings['container_yamls']['arangodb.logger'] = 'modules/contrib/arangodb/arangodb.services.logger.yml';

Feature - Lock

To store locks with arangodb module isn't activated by default. In order to use ArangoDB as lock storage, the following line has to be added to the settings.local.php.

settings.local.php

$settings['container_yamls']['arangodb.lock'] = 'modules/contrib/arangodb/arangodb.services.lock.yml';

Feature - Flood

To store flood events with arangodb module isn't activated by default. In order to use ArangoDB as flood event storage, the following line has to be added to the settings.local.php.

settings.local.php

$settings['container_yamls']['arangodb.flood'] = 'modules/contrib/arangodb/arangodb.services.flood.yml';

Feature - KeyValue

Tasks:

• Basic implementation
• write more tests

Feature - KeyValue - configuration

ArangoDB module defines a few KeyValue factory services in the arangodb.services.yml.
These service names can be listed by the following command:

yq eval \
  '.services | keys | .[] | select(test("^arangodb\.keyvalue\.factory\."))' \
  'arangodb.services.yml'

• arangodb.keyvalue.factory.simple_shared_php
• arangodb.keyvalue.factory.simple_shared_loafer
• arangodb.keyvalue.factory.simple_dedicated_php
• arangodb.keyvalue.factory.simple_dedicated_loafer
• arangodb.keyvalue.factory.expirable_shared_php
• arangodb.keyvalue.factory.expirable_shared_loafer
• arangodb.keyvalue.factory.expirable_dedicated_php
• arangodb.keyvalue.factory.expirable_dedicated_loafer

A „KeyValue collection” can be paired with a „KeyValue storage factory” in an additional services.*.yml file.

parameters:
  factory.keyvalue:
    my_module_01_collection_01: 'arangodb.keyvalue.factory.simple_shared_php'
  factory.keyvalue.expirable:
    my_module_01_collection_02: 'arangodb.keyvalue.factory.expirable_shared_php'

Usage:

/** @var \Drupal\Core\KeyValueStore\KeyValueStoreInterface $simple_storage */
$simple_storage = \Drupal::getContainer()
  ->get('keyvalue')
  ->get('my_module_01_collection_01');
$simple_storage->set('my_key_01', 'my_data_01');

/** @var \Drupal\Core\KeyValueStore\KeyValueStoreExpirableInterface $expirable_storage */
$expirable_storage = \Drupal::getContainer()
  ->get('keyvalue.expirable')
  ->get('my_module_01_collection_02');
$expirable_storage->setWithExpire('my_key_02', 'my_data_02', 3600);

The „KeyValue collection” identifiers are defined by modules on demand.
There is no hook or any kind of API to get a list of the possible „KeyValue collection” identifiers.

A „KeyValue collection” which has no dedicated „KeyValue storage factory” will uses the default factory.
By default the default factory is keyvalue.database.
See \Drupal\Core\KeyValueStore\KeyValueFactory::DEFAULT_SERVICE.
The default factory can be changed in a services.*.yml file.

parameters:
  factory.keyvalue:
    default: '<name of a keyvalue factory service>'
  factory.keyvalue.expirable:
    # https://www.drupal.org/project/drupal/issues/2769955
    keyvalue_expirable_default: '<name of a keyvalue factory service>'

I am not sure if a KeyValue factory service from custom module works during the installation.

Feature - State

In the background State uses the KeyValue as storage backend.
The KeyValue collection name is state.

Feature - Session

@todo list

1. Create an individual package sweetchuck/php-session-arangodb
   1. PHP Session
   2. Symfony compatible session storage.
   3. Example implementation: symfony/http-foundation#/Session/Storage/Handler
   4. Framework (Drupal) independent.
2. Drupal integration.

Feature - Config entity storage

@todo

Feature - Content entity storage

@todo

Feature - Full database driver

@todo

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