Laravel 9 - guide with Concurrent Database Transactions Causing Race Conditions
I need help solving I'm converting an old project and I tried several approaches but none seem to work... After trying multiple solutions online, I still can't figure this out. I'm working on a Laravel 9 application that involves multiple users updating the same resource in a database simultaneously. I've implemented a feature where users can update their profile information, and I'm using Eloquent's transactions to ensure data integrity. However, I've been experiencing race conditions that lead to unexpected behavior where sometimes the last update isn't reflected in the database. Here's the relevant code snippet for the update method in my controller: ```php public function updateProfile(Request $request) { $validatedData = $request->validate([ 'name' => 'required|string|max:255', 'email' => 'required|string|email|max:255|unique:users,email,' . auth()->id(), ]); DB::transaction(function () use ($validatedData) { $user = User::find(auth()->id()); $user->name = $validatedData['name']; $user->email = $validatedData['email']; $user->save(); }); } ``` The scenario arises when two users attempt to update their profiles at the same time. I see the following behavior in the logs: ``` SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry 'email@example.com' for key 'users.email_unique' ``` I tried locking the user record using `DB::table('users')->lockForUpdate()` before the transaction, but it doesn’t seem to resolve the concurrency scenario. I am also using MySQL with the InnoDB storage engine, which I thought would help with transaction handling. I'm unsure if I should implement optimistic locking or if there's a better way to handle concurrent updates in this scenario. Any insights on how to resolve these race conditions effectively would be greatly appreciated! Has anyone else encountered this? Any ideas what could be causing this? Has anyone dealt with something similar? Any feedback is welcome!