多次击中时，单个php文件的连接太多

I am trying to run a php file through shell script multiple times.

I open connection like this (index.php).

mysqli_connect('localhost', 'root', 'password', 'database')

I got following error

mysqli_connect(): (HY000/1040): Too many connections

I could increase max_connections in mysql my.cnf file. But I think this is not a good idea because it slows things down.

Here is my .sh file code when I run. It hits php file 750 times

#!/bin/bash

max=750
for i in `seq 0 $max`
do
    php index.php $i &
done

Can I share one connection across a file when it is hit simultaneously? Or is there any better approach?

Any Help?