Are optimistic locking or pessimistic locking used when updating wallet balances?

[704403314]

To ensure the accuracy of wallet balances under high concurrency, are optimistic locking or pessimistic locking used when updating wallet balances?
For example, if a user's current wallet balance is 0 and they initiate two refund transactions simultaneously, each refund requiring an increase of 100 units to the wallet balance. In a high concurrency situation, it is possible that both refund transactions start with a balance query of 0. Consequently, each transaction increases the balance by 100 units based on the initial balance of 0, resulting in a final wallet balance of 100 units for the user, whereas it should have been 200 units.

[rez1dent3]

Hello. It depends on the cache and lock settings. If you leave array, then there will be no locks.

I recommend using redis sentinel for cache and lock. But you can use a database for cache, then you will get full-fledged transactions at the database level.

laravel-wallet/config/config.php

Lines 65 to 79 in 9b0bd38

	/**
	* Storage of the state of the balance of wallets.
	*/
	'cache' => [
	'driver' => env('WALLET_CACHE_DRIVER', 'array'),
	'ttl' => env('WALLET_CACHE_TTL', 24 * 3600),
	],
	/**
	* A system for dealing with race conditions.
	*/
	'lock' => [
	'driver' => env('WALLET_LOCK_DRIVER', 'array'),
	'seconds' => env('WALLET_LOCK_TTL', 1),
	],

Hm. It will be necessary to add a functional test for the database as cache... Thank you)