504 Gateway Time-out

I am using Virtualmin on CentOs 6.3. My PHP script execution mode is CGI wrapper (run as virtual server owner). When some one open heavy process php file (eg. display all record for database) then browser alsways in waiting mode and it returns 504 Gateway Time-out. I am not able to solve this issue please help me. I have same server with same application with cpanel it working fine.

Closed (fixed)