Web Servers??

Web Servers


What are Web Servers? How exactly do they work? What are the different kinds and what are the considerations one should take in configuring one?

"Web server" can refer to hardware or software, or both of them working together.

1. On the hardware side, a web server is a computer that stores a website's component files (e.g. HTML documents, images, CSS stylesheets, and JavaScript files) and delivers them to the end-user's device. It is connected to the Internet and can be accessed through a domain name like mozilla.org.

2. On the software side, a web server includes several parts that control how web users access hosted files, at minimum an HTTP server. An HTTP server is a piece of software that understands URLs (web addresses) and HTTP (the protocol your browser uses to view webpages).

At the most basic level, whenever a browser needs a file hosted on a web server, the browser requests the file via HTTP. When the request reaches the correct web server (hardware), the HTTP server (software) sends the requested document back, also through HTTP.

To publish a website, you need either a static or a dynamic web server.

A static web server, or stack, consists of a computer (hardware) with an HTTP server (software). We call it "static" because the server sends its hosted files "as-is" to your browser.

A dynamic web server consists of a static web server plus extra software, most commonly an application server and a database. We call it "dynamic" because the application server updates the hosted files before sending them to your browser via the HTTP server.

For example, to produce the final webpages you see in the browser, the application server might fill an HTML template with contents from a database. Sites like MDN or Wikipedia have many thousands of webpages, but they aren't real HTML documents, only a few HTML templates and a giant database. This setup makes it easier and quicker to maintain and deliver the content.

Reference: developer.mozilla.org/en-US/docs/Learn/Common_questions/What_is_a_web_server

What are Web Servers?
Web servers are computers that deliver (serves up) Web pages. Every Web server has an IP address and possibly a domain name.

How exactly do they work?
If you enter any URL into your browser, this sends a request to the Web server of the domain name in which you entered . The server then fetches the page named index.html and sends it to your browser.

What are the different kinds and what are the considerations one should take in configuring one?
The different kinds of Apache HTTP Server, Internet Information Services, lighttpd, Sun Java System Web Server are just a example of a few. The considerations for configuring a web server is ensuring that you have a:
1. Back Up System which  will grant you with the ability to create periodic backups of your data, and restore data from backups. Backups also allow for rollbacks in your data, to a previous state, in the event of accidental deletion or undesired modification, which can occur due to a variety of reasons including human error.

2.Recovery plans are a set of documented procedures to recover from potential failures or administration errors within your production environment. At minimum, you will want a recovery plan for each crippling scenario that you deem will inevitably occur, such as server hardware failure or accidental data deletion.

3. Load balancing can be added to a server environment to improve performance and availability by distributing the workload across multiple servers. If one of the servers that is load balanced fails, the other servers will handle the incoming traffic until the failed server becomes healthy again.

4. Monitoring can support a server environment by tracking the status of services and the trends of your server resource utilization, thus providing great visibility into your environment.

5. Centralized logging can support a server environment by providing an easy way to view and search your logs, which are normally stored locally on individual servers across your entire environment, in a single place.

A Web server is a program that uses HTTP (Hypertext Transfer Protocol) to serve files that form web pages to users, in response to their requests, or simply a computer program that dispenses web pages as they are requested.

The web browser first needs to know which IP address the domain name resolves to. If it doesn't already have this information stored in it's cache, it requests the information from one or more DNS servers via the internet and the tells the browser this IP address. After getting this information, the web browser requests the full URL from the web server. The web server responds by sending back the requested page and displays it.

The different kinds of servers include Proxy Server,Mail Server, Web Server,Application Server, Real-Time Communication Server,FTP Server, Collaboration Server, List Server,
Telnet Server, Open Source Server, and Virtual Servers.

When configuring a server, requirements such as space/capacity, environment, backup, up time, IS provider etc. should be considered in order to provide efficient services.

A WEB SERVER IS A PROGRAM THAT USES HTTP TO SERVE FILES THAT FORM WEB PAGES TO USERS.

DIFFERENT KIND OF SERVERS ARE PROXY SERVER, MAIL SERVER, WEB SERVER ETC.

CONFIGURING A SERVER ONE SHOULD TAKE INTO CONSIDERATION ARE THE ENVIRONMENT, BACKUP, PERFORMANCE, LOAD BALANCING ETC.

THE WEB SERVER WORKS AS AN ADDRESS TRANSLATOR...BETTER PUT A USER REQUESTS A URL...IT SENDS A REQUEST TO THE SERVER OF THE DOMAIN.. THE SERVER THEN FETCHES THE PAGE WITH THAT INDEX.HTML

The definitions of the web server object are made using the wsadmin command or the administrative console. You can also define a web server object in the WebSphere Application Server repository using the profile create script during installation, a .jacl script, and by using the administrative console wizard.
There are three types of WebSphere Application Server nodes upon which you can create a web server. The type depends on the version of WebSphere Application Server, as follows:

Managed node. A node that contains a node agent. This node can exist only in a deployment manager environment. The importance of defining a web server on a managed node is that the administration and configuration of the web server is handled through the node agent from the administrative console. Support for administration and configuration through the administrative console is limited to IBM® HTTP Server only. Non-IBM HTTP Server web servers must be on a managed node to handle plug-in administrative functions and the generation and propagation of the plugin-cfg.xml file.
Stand-alone node. A node that does not contain a node agent. This node usually exists in WebSphere Application Server (base) or WebSphere Application Server Express® environment. A stand-alone node can become a managed node in a deployment manager environment after the node is federated . A stand-alone node does not contain a node agent, so to administer and manage IBM HTTP Server, there must be an IBM HTTP Server administration server installed and running on the stand-alone machine that the node represents. IBM HTTP Server ships with the IBM HTTP Server administration server and is installed by default. Support for administration and configuration through the administrative console is limited to IBM HTTP Server only.
Unmanaged node. A node that is not associated with a WebSphere Application Server node agent. This node cannot be federated. Typically, the unmanaged node represents a remote machine that does not have WebSphere Application Server installed. However, you can define an unmanaged node on a machine where WebSphere Application Server is installed. This node can exist in aWebSphere Application Server (base), WebSphere Application Server Express, or deployment manager environment. An unmanaged node does not contain a node agent, so to administer and manage IBM HTTP Server, an IBM HTTP Server administration server must be installed and running on the stand-alone machine that the node represents. Support for administration and configuration through the administrative console is limited to IBM HTTP Server only.

A Web server is a program that uses HTTP (Hypertext Transfer Protocol) to serve the files that form Web pages to users, in response to their requests, which are forwarded by their computers' HTTP clients. Dedicated computers and appliances may be referred to as Web servers as well.The domain name server is usually run by your ISP or by the company. The browser establishes a connection channel with the web server on the computer which IP address was given by the DNS server and requests the document on the host.

A Web server is a system that delivers content or services to end users over the Internet. A Web server consists of a physical server, server operating system (OS) and software used to facilitate HTTP communication.A Web server is also known as an Internet server.
How does it works?
The domain name server is usually run by your ISP or by your company. The browser establishes a connection channel with the web server on the computer which IP address was given by the DNS server and requests the document on the host which name is www.aprelium.com and which virtual path is doc/sample.html .
Different Type of severs
Apache HTTP Server,Internet Information Services,ighttpd,Sun Java System Web Server and Jigsaw Server
Considerations
For Apache web sever
Use HTTPS for the Endpoint Application Control web console, enable and configure SSL for Apache Tomcat. See TLS/SSL Considerations.

To avoid some common security compromises, do the following:

Create a non-administrator account to run Apache Tomcat.

By default, the administrator account is the only account in Apache Tomcat. To help avoid the Endpoint Application Control server becoming compromised if a malicious hacker takes control of your Apache web server, Trend Micro recommends creating a different account to run the web server.