Load Balancing for Custom PHP App with heavy traffic
I'm using Digital Ocean server with 48 GB of RAM, and 12 Core Processors for my custom php web app. Now, the daily pageview is up to 500000 and my server can't serve the app and the website is very slow loading speed. CPU usage is too much due to heavy traffic. So, I'm finding the solution to solve the problem. One of my friend suggests to use Load Balancing for my app. I'm not familiar with load balancing method and now I find the solution for my problem in this discussion .
My app is web based Facebook Quiz using PHP and the main function of my app is to generate images for user. Now, the server can't handle the heavy traffic and slows in generating image results.
To set load balancing for my php web app, what is the minimum requirement for server ?
Now, I'm using Debian OS and daily pageview is around 500000 . I'm also use Cloudflare CDN service. Please kindly help me to solve my problem . Thanks for all.