$ _REQUEST数组为空，但显示个别值

I just built my web server to Centos 7 and now this no longer works:

print_r($_REQUEST);

and shows an empty array...

but this below does if am looking at a specific variable value

echo($_REQUEST["name"]);

it appears it won't let you know all the values of $_REQUEST without knowing the specific name of the variable.

Is this a setting i need to change in PHP.INI or something? Some change in php?

This worked fine with Centos 5, and this was broken when I moved these existing sites over to the new server.

Thanks