Is that possible to use Yii2 + MySql in Rapache server?

Question

I have yii2 project and use R code for report and image generation. I use PHP exec() + Rscript for now. But it has some issue like ONLY ONE USER can be using the web app at a time. i try use PHP exec() Parallel Processing approach :

exec("Rscript Rcode > file.txt &");

But it doesn't work (i dont know why..). so i should try another way, and i hear about Rapache / opencpu.

So, i have some questions:

1. Are Rapache / opencpu can handle multiple request?

2. Is that possible to make yii2 project in Rapache/opencpu?

3. if is possible to use php exec() that can handle multiple request, how can i do that?