How do slow requests block apache in prefork mode?

Question

Nginx

In the process of studying the configuration of the server, several questions arose.
Do I understand correctly that if apache is running in prefork mode, and MaxClients=2 then ...
1. If 2 visitors with a slow Internet connection access the server at the same time, then the third client will have to wait until one of the slow connections is completed?
2. Nginx as a proxy after Apache - will it fix this and the third client will not have to wait?
3. If I understand point 2 correctly, how will the situation change when 2 slow clients do not receive, but send information to the server via POST? The third client will again be forced to wait, even if there is Nginx?
MaxClients=2 is just for clarity.

Answer 1

Nginx waits for a full request, then immediately sends it to Apache, then receives a response and passes it to the user.

Answer 2

1. They will wait or Apache will swear with a 5XX error. This error page can be customized - “Wait. Heavy load on the server.
2. Nginx itself can give static files (images, css, js ..) without proxying them to apach. But page generation will be handled by apache.
The logic is this: nginx is configured as a front-end server in front of apache for quick return of statics (pictures, css, js). Behind nginx, they put apache as a back-end server for generating pages and processing input parameters.
3. Will wait.
We make nginx as front-end to apache