What do you mean by "Most PHP ... is not stateless"?
Usually, the state of PHP app is in the DB.
Other "state data" are:
1) sessions. By default saved in files, can be moved to DB, making PHP stateless
2) storage (i.e. user's attachments). To decouple from PHP server, - need to switch to object storage service.
So, it's not hard.
But most popular PHP application - WordPress if failing to be stateless, because of number 2: it uses local storage for plugins, media, user's data.
> To decouple from PHP server, - need to switch to object storage service.... So, it's not hard.
If you are the developer of the app, that's true. If you're the ops guy to whom the app was lobbed over the wall to, it's not quite that simple without making code changes to the app. In the case of Wordpress also, it's been my experience that many of the "developers" are just marketing people and don't actually write code. These people are not equipped to remove state from the app either.
Usually, the state of PHP app is in the DB. Other "state data" are: 1) sessions. By default saved in files, can be moved to DB, making PHP stateless 2) storage (i.e. user's attachments). To decouple from PHP server, - need to switch to object storage service.
So, it's not hard.
But most popular PHP application - WordPress if failing to be stateless, because of number 2: it uses local storage for plugins, media, user's data.