Charge the card, send the receipt, ack the job. The worker lost its Redis connection between step one and step three. The queue delivered the job again. The customer paid twice. Support learned some new words from him. Retries are not an edge case. Laravel retries failed jobs by design, and you want that, because networks blink. So every job with a side effect must answer one question: what happens if this runs twice. “It will not run twice” is not an answer. It will. ...
Validate input, reserve stock, create the order, charge the card, fire events. Five steps in one checkout action, and the fat model versus fat controller argument offers only two rooms for them. Both rooms are wrong. Put it all in the controller and you cannot run checkout from anywhere except HTTP. No console command, no queue job, no test without the kernel. Put it in the Order model and the model now knows about payments, stock and notifications, a strange set of friends for an Eloquent class. ...
The row in users. Then orders, with the delivery address and phone. Then nginx access logs with emails inside GET parameters of an old unsubscribe endpoint. That is how far I got in the first ten minutes of drawing where one user’s data lives on one project, and the map did not fit on one page. May 25 is close and everyone discusses consent banners. The lawyers can have the banners. The engineering part is the right to erasure. “Delete the user” sounds like one DELETE statement until you sit down with a pen. ...
$container->get('app.mailer') stopped working this week. Symfony 3.3 is out, and in the new configuration services are private by default. The container refuses the call. Everyone is writing about autowiring. This is the change I like more. That call was always a smell. A class that pulls dependencies from the container by string id is a class with secrets. Its constructor says nothing, and to test it you boot half the framework, because it may ask for anything at any moment. ...
if ($order->status == 'paid') in the shipping module. Another one in the refund module. A slightly different one in the admin panel. Then someone cancels a shipped order from an admin button, because the button just writes the string, and the warehouse learns about it a week later. Symfony 3.2 is out this week and ships a Workflow component. Finally a framework says out loud what every order table has been whispering for years: status is a state machine, not a string column you assign wherever convenient. ...
The job called the payment provider. The call succeeded. Then the worker timed out before it marked the job done. The queue did what queues do: it retried. The provider did what it was asked: it charged again. The customer did what customers do and wrote an angry email. Nobody made a mistake here. The queue promises at-least-once delivery, and “at least” is written in the contract. Network partitions, worker crashes, deploy restarts. Sooner or later every job runs twice, and the jobs that hurt are exactly the ones with external effects: payments, emails, webhooks, API calls. ...
Mail::send() inside the checkout controller. A second copy inside the API controller. Then someone adds the chat webhook to one copy and forgets the other. Every project has this code. I have written it more than once. Laravel 5.3 came out this week, and the two big pieces, Notifications and Passport, both point the same way. The application is no longer a thing that renders HTML. It is a core that talks to browsers, mobile clients and third parties, and HTML is one of the outputs. ...
Kohana 3.3, on a project that earns money every day. The framework is effectively finished. The repository barely moves, the community left years ago. Nobody will approve a rewrite, and I have stopped asking. This is a normal situation and it deserves a better plan than “someday we migrate”. The plan we settled on is a freeze. Pin the exact framework version and vendor it. Not “3.3.*”, the exact commit. The build must be reproducible in five years, when the original download link is dead. ...
Symfony 2.8 and 3.0, released today, both at once, on purpose. The pairing is the whole message. 2.8 is the last of the 2.x line and an LTS. 3.0 is roughly 2.8 with the deprecated code deleted. Same features, cleaner body. This turns a scary major upgrade into two steps. Step one, move to 2.8. Minor upgrade, low risk. Then make the deprecation log empty. The phpunit bridge prints every deprecated call your code and tests touch. Burn the list down during normal sprints, item by item, each fix small and releasable on its own. ...
Two lines from redis.conf on one project: maxmemory 2gb maxmemory-policy allkeys-lru Correct for a cache. Then sessions moved into the same instance, because Redis was already there. Then the job queue, same reason. One process, three tenants. This works until the day it does not. Cache data is disposable by definition, and those two lines embrace that. Memory fills up, Redis evicts the coldest keys, the application rebuilds them on demand. Persistence is optional. After a restart a cold cache is an inconvenience, not an incident. ...