Most of the times these terms Web Server and Application server are used interchangeably.
Following are some of the key differences in features of Web Server and Application Server:
- Web Server is designed to serve HTTP Content. App Server can also serve HTTP Content but is not limited to just HTTP. It can be provided other protocol support such as RMI/RPC
- Web Server is mostly designed to serve static content, though most Web Servers have plugins to support scripting languages like Perl, PHP, ASP, JSP etc. through which these servers can generate dynamic HTTP content.
- Most of the application servers have Web Server as integral part of them, that means App Server can do whatever Web Server is capable of. Additionally App Server have components and features to support Application level services such as Connection Pooling, Object Pooling, Transaction Support, Messaging services etc.
- As web servers are well suited for static content and app servers for dynamic content, most of the production environments have web server acting as reverse proxy to app server. That means while servicing a page request, static contents (such as images/Static HTML) are served by web server that interprets the request. Using some kind of filtering technique (mostly extension of requested resource) web server identifies dynamic content request and transparently forwards to app server
Example of such configuration is Apache Tomcat HTTP Server and Oracle (formerly BEA) WebLogic Server. Apache Tomcat HTTP Server is Web Server and Oracle WebLogic is Application Server.
In some cases the servers are tightly integrated such as IIS and .NET Runtime. IIS is web server. When equipped with .NET runtime environment, IIS is capable of providing application services.
Simplest Node.js server is just:
$ npm install http-server -g
Now you can run a server via the following commands:
$ cd MyApp
$ http-server
If you're using NPM 5.2.0 or newer, you can use http-server
without installing it with npx
. This isn't recommended for use in production but is a great way to quickly get a server running on localhost.
$ npx http-server
Or, you can try this, which opens your web browser and enables CORS requests:
$ http-server -o --cors
For more options, check out the documentation for http-server
on GitHub, or run:
$ http-server --help
Lots of other nice features and brain-dead-simple deployment to NodeJitsu.
Feature Forks
Of course, you can easily top up the features with your own fork. You might find it's already been done in one of the existing 800+ forks of this project:
Light Server: An Auto Refreshing Alternative
A nice alternative to http-server
is light-server
. It supports file watching and auto-refreshing and many other features.
$ npm install -g light-server
$ light-server
Add to your directory context menu in Windows Explorer
reg.exe add HKCR\Directory\shell\LightServer\command /ve /t REG_EXPAND_SZ /f /d "\"C:\nodejs\light-server.cmd\" \"-o\" \"-s\" \"%V\""
Simple JSON REST server
If you need to create a simple REST server for a prototype project then json-server might be what you're looking for.
Auto Refreshing Editors
Most web page editors and IDE tools now include a web server that will watch your source files and auto refresh your web page when they change.
I use Live Server with Visual Studio Code.
The open source text editor Brackets also includes a NodeJS static web server. Just open any HTML file in Brackets, press "Live Preview" and it starts a static server and opens your browser at the page. The browser will auto refresh whenever you edit and save the HTML file. This especially useful when testing adaptive web sites. Open your HTML page on multiple browsers/window sizes/devices. Save your HTML page and instantly see if your adaptive stuff is working as they all auto refresh.
Web / SPA / PWA / Mobile / Desktop / Browser Ext Web Developers
Some SPA frameworks include a built in version of the Webpack DevServer that can detect source file changes and trigger an incremental rebuild and patch (called hot reloading) of your SPA or PWA web app. Here's a few popular SPA frameworks that can do this.
VueJS Developers
For VueJS developers, a favorite is Quasar Framework that includes the Webpack DevServer out of the box with switches to support server-side rendering (SSR) and proxy rules to cure your CORS issues. It includes a large number of optimized components designed to adapt for both Mobile and Desktop. These allows you to build one app for ALL platforms (SPA, SPA+SSR, PWA, PWA+SSR, Cordova and Capacitor Mobile AppStore apps, Electron Desktop Node+VueJS apps and even Browser extensions).
Another popular one is NuxtJS that also supports static HTML/CSS code generation as well as SSR or no-SSR build modes with plugins for other UI component suites.
React Framework Developers
ReactJS developers can also setup hot reloading.
Cordova/Capacitor + Ionic Framework Developers
Iconic is a mobile only hybrid component framework that now supports VueJS, React and Angular development. A local server with auto refresh features is baked into the ionic
tool. Just run ionic serve
from your app folder. Even better ... ionic serve --lab
to view auto-refreshing side by side views of both iOS and Android.
Best Answer
Pre-forking basically means a master creates forks which handle each request. A fork is a completely separate *nix process.
Pre-forking can be used when you have libraries that are NOT thread safe. It also means issues within a request causing problems will only affect the process which they are processed by and not the entire server.
The initialisation running multiple times all depends on what you are deploying. Usually however connection pools and stuff of that nature would exist for each process.
In a threading model the master would create lighter weight threads to dispatch requests too. But if a thread causes massive issues it could have repercussions for the master process.
With tools such an Nginx, Apache 2.4's Event MPM, or gevent (which can be used with Gunicorn) these are asynchronous meaning a process can handle hundreds of requests whilst not blocking.