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ldsrogan
ldsrogan

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Web Server & Web Application Server

Web Server

Web server is a program that provides static contents like HTML documents by receiving HTTP request from the web browser (client).

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Static contents mean that no matter what parameters or users will be, the response always includes the same contents.

Web Server's Functionalities

  • Receives HTTP request from the client
  • For static contents, the server can provides static contents (html, jpeg, css, etc.)
  • For dynamic contents, the server delivers dynamic contents request to Web Application Server (WAS), and pass results from the WAS.

Web Application Server (WAS)

Web application server is a program that is implemented for providing dynamic contents which require various logic processes or DB queries.

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Dynamic contents can be varied from the input parameters or users

WAS can

  • directly receive HTTP request from the client
  • provide static contents (html, jpeg, css, etc.)
  • provide dynamic contents by processing various logics and DB query

Why we need WS for WAS?

  • We may need WS because we can separate the roles between WS (for static contents) and WAS (for dynamic contents).
  • If we use multiple WAS, then WS can be a load balancer to distribute the request calls from the client.
  • WS can regularly check the WAS health (check if response comes correctly)
  • We can use reverse proxy from WS to secure the data from the WAS.

Common Web Server Software

  • Apache HTTP server
  • Nginx
  • Sun Java System Web Server
  • ...

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