[omnimus]

In a sense thats blue-green deployment just on filesystem level? PHP is always run behind proxy/webserver (mostly ngnix nowdays)

But you are right there is no reason why you couldn't have two instances of the php app runing and switch between them. For some reason the PHP deployment services i've used seem to use the filesystem approach and i doubt it's laziness or incompetence.

[kstrauser]

I'd content that it's out of ignorance, and I don't mean that in a mean or nasty way. I've heard lots of pushback from PHP devs that it's way easier to update than sites written in other languages are, but I think it's genuinely due to a lack of understanding of why those languages recommend other upgrade processes. Those processes solve real, genuine problems that also affect PHP, but they're dismissed as overkill or enterprisey or overly complicated.

And all that may be true for a trivial website. If you've written a personal project with 10,000 hits per year, YOLO. Go for it. The odds of it affecting one of those users is vanishingly tiny, and so what if it does? But if you're hosting something like a Wordpress site for a large company with lots of traffic, it's crucial to understand why "just rsync the files over" is not an acceptable deployment method.

[omnimus]

Sorry but we were not talking about “rsyncing the files over”. We are talking about what services that i've used like Forge or Ploi do where you deploy project into separate folder and then switch symlink. You can even roll it back.

I have a feeling you want to dunk on poor dumb PHP developer but like Forge is by the people who created Laravel. I believe they would put some thought into it. Maybe just maybe small chance of one bad request is not such a bad deal.

[kstrauser]

It is literally exactly the same issue, just with slightly less of an error window. I don't think those devs are poor and dumb, but I do think it's likely they've been working in environments where production errors are more tolerated than in other environments.

> Maybe just maybe small chance of one bad request is not such a bad deal.

If your company is OK with that, seriously, sincerely, right on! Keep doing this and move on to other problems.

[omnimus]

I had thought about it and you are just pulling my nose.

If you have very long database query and you update your app in middle of it using blue-green load balancer you get to same production error. It is the same thing just implemented slightly differently because of PHP characteristics allow this and with different systems you have to use different strategy.

So yeah have good feeling about us PHP devs having bad deployment strategies.

[kstrauser]

That is… exactly wrong. I encourage you to consider why that would not be the case.

[spdionis]

It is not the same issue, due to how opcache works. No one remotely competent runs PHP without opcache in 2025.