Как хранятся заказы корзины каталога Как применяется механизм карты спотов для распределения данных Как встроить код роутинга запросов в active record фреймворка Laravel Как написать behat-тесты, покрывающие распределенную структуру хранения

1. Шардинг заказов
корзины каталога
Петр Трофимов

3. 600 разделов
800 000 товаров
1000+ магазинов
и почти 5 000 000позиций

4. Cart.api
app1
app2
app3
app4
...
db1
db2
db3
db4
...
order
order1
order2
orderN
credentials.api
catalog.api
shop.api
geo.api

5. host1
db1
table1
Споты
spot1 spot2
table2
spot3
db2
spot4
spot5
host2
spot6
spot7
hostN

6. Карта спотов
start_id finish_id connection_name database spot_prefix
1 1000000 host100 cart10 chunk1_
1000001 2000000 host101 cart11 chunk2_
... ... ... ... ...
10000001 0 host110 cart120 chunk10_

7. abstract class Model extends EloquentModel
{
protected $spotIdKey;
public function spot()
{
return $this->spot ? : Map::spot($this->getAttributeFromArray($this->spotIdKey));
}
public function getConnection()
{
return $this->spotConnection($this->spot());
}
public function spotConnection(Spot $spot)
{
$configKey = "database.connections.{$spot->connectionName}";
if (!config($configKey)) {
app('config')->set($configKey, $this->spotConfig($spot));
}
return static::resolveConnection($spot->connectionName);
}
public function getTable()
{
return $this->spot()->database . '.' . $this->spot()->spotPrefix . parent::getTable();
}
}

8. Как искать в спотах?
spot1 spot2 spot3 spot4 spotN
client
SELECT * FROM orders WHERE shop_id = ?

9. Превью
spotN spot2 spotN
client
preview
preview
WRITE READ
client
spot1
preview
spot3

10. class PreviewUpdater
{
public function created(Order $order)
{
OrderPreview::create([
'id' => $order->id,
'user_id' => $order->user_id,
'status' => $order->status,
// ...
]);
}
public function updated(Order $order)
{
/** @var OrderPreview $orderPreview */
$orderPreview = OrderPreview::find($order->id);
$orderPreview->user_id = $order->user_id;
$orderPreview->status = $order->status;
// ...
$orderPreview->save();
}
public function deleted(Order $order)
{
OrderPreview::destroy($order->id);
}
}

11. abstract class Model extends EloquentModel
{
public static function find($id, $columns = ['*'])
{
if (is_array($id)) {
return static::findMany($id, $columns);
}
return static::spotQuery(Map::spot($id))->find($id, $columns);
}
public static function spotQuery(Spot $spot)
{
$instance = new static;
$instance->spot = $spot;
$connection = $instance->spotConnection($spot);
$builder = $instance->newEloquentBuilder(
new QueryBuilder($connection, $connection->getQueryGrammar(), $connection->getPostProcessor())
);
return $builder->setModel($instance);
}
// ...
}

12. $order = OrderPreview::orderQuery()->whereOrderKey($orderId)->first();
class OrderPreview extends Model
{
public static function orderQuery()
{
$instance = new static;
return (new QueryBuilder($instance->newBaseQueryBuilder(), new Order))->setModel($instance);
}
}
class QueryBuilder extends Builder
{
/** @var Model */
private $spotted;
private $with = [];
public function getModels($columns = ['*'])
{
return $this->spotted->findMany(array_pluck(parent::getModels($columns), 'id'), $columns,
$this->with)->all();
}
}
Запросы через превью

13. abstract class Model extends EloquentModel
{
public function hasMany($related, $foreignKey = null, $localKey = null)
{
//...
$instance = new $related;
$instance->spot = $this->spot();
return new HasMany(/*...*/, $instance->getTable() . '.' . $foreignKey);
}
}
Поддержка relations

14. Scenario: Spots with different databases
Given spots map contains spots:
| start_id | finish_id | connection_name | database | spot_prefix |
| 1 | 1 | catalog_cart | <test_db> | |
| 2 | 2 | catalog_cart_spot2 | <test_db>_spot2 | |
# ...
When I send POST request to "/orders"
Then request expectations should be met
And log file should be empty
And response status code should be 201
And SQL query "select * from <test_db>.orders" result should be like:
| id | user_id | shop_id | status | delivery_city | delivery_address | comment |
| 1 | 1 | 1 | 0 | Минск | пр-т Дзержинского, 5 | comment1 |
# ...
Behat-сценарии для спотов

15. Спасибо за внимание. Вопросы?
● https://catalog.onliner.by/
● https://cart.onliner.by/
● http://php.spb.ru/ms/description.html
● https://engineering.instagram.com/sharding-ids-at-
instagram-1cf5a71e5a5c

16. Генерация ID
● Auto-increment ID (1, 2, 3, …)
○ Закрыть информацию
○ Шардинг
● Hashids (3jR-OCl4rG0)
○ Number vector
○ Недостаточно безопасные
● UUID (550e8400-e29b-41d4-a716-446655440000)
○ Нечитаемые
● ID sequence
○ Читаемый набор символов (без i и 1)
○ Единый центр выдачи идентификаторов
○ Механизм отслеживания коллизий

17. $this->sequence = $connection->table('order_id_sequence');
// ...
for ($i = 1; $i <= config('order.key.collisions.limit'); $i++) {
try {
$order->key = $this->generateOrderKey();
$order->id = $this->sequence->insertGetId(['order_key' => $order->key]);
return;
} catch (QueryException $ex) {
if ($ex->getCode() != 23000) { // Integrity constraint violation
throw $ex;
}
}
if ($i == config('order.key.collisions.warning')) {
(new OnlinerLogger)->warning(
"cart-api: $i collisions occurred, think about increasing of order key length"
);
}
}
throw new RuntimeException(
"Failed to generate key for order from user {$order->user_id} to shop {$order->user_id}"
);

18. class Order extends SpotsModel
{
public $incrementing = false;
protected $spotIdKey = 'id';
protected $table = 'orders';
public function statusLogEntries()
{
return $this->hasMany(OrderStatusLogEntry::class);
}
public function save(array $options = [])
{
if (!$this->exists) {
// ...
app(IdGenerator::class)->generate($this);
}
return parent::save($options);
}
protected static function boot()
{
parent::boot();
// ...
static::observe(PreviewUpdater::class);
}
}