But the contents on the CMS become huge and the UI become rich, the response of the browser become very slow. The response of the application hosted on the localhost is quick.
Therefore I thought the reason of slow response is not CPU and memory, but the networking speed.
Recently, low cost and high performance cloud server is available, and the performance of the server's executing program is very fast. By using the "top" command of the Linux, we can confirm that.
But the network capacity is not so high, or the cloud service provider quotes the traffic amount from single IP address.
So, I think the Http Cache Control is essential to use cloud.
I implemented the Http Cache Control and tried it, in this website. The response of the UI become very quickly.
And I also implemented reply for the "If-Modified-Since" header. This header is necessary for the googlebot to decrease unnecessary traffic. Before implementing this, we can do it by apache server using mod_ajp.
But the Tomcat is also good web server, and opportunities to use it stand alone increases when you build container based Docker image.
So, I'll study the configuration of the tomcat, and find the way to use it efficiently.