A network is a group of two or more computer systems sharing services and interacting in some manner. In most cases, this interaction is accomplished through a shared communication link, with the shared components being data. Put simply, a network is a collection of machines that have been linked both physically and through software components to soothe communication and the sharing of information. The Internet is, literally, a network of networks. It is made of thousands of interconnected networks spanning the globe.
The computers that form the Internet range from huge mainframes in research establishments to humble PCs in people’s homes and offices. The Internet has become a very important learning tool. It is used for day-to-day activities, such as a place to look up research, a method of getting in touch with friends and family, and somewhere to go to find information about almost anything imaginable. The most popular uses of the Internet include entertainment and education.
The objective of this paper is to constructively discuss and show the many components of the internet such as Server Side Processing, Client Side Display, Java Servlets, ASP, CGI, and more. The phrase server side processing (SSP) refers to what is commonly called SSI or server-parsed html, or a number of other things. These refer to when the server parses the HTML file, looking for strings that cause it to add content or remove from the HTML that is going to be delivered to the client.
Typical uses for SSP are including the current date, the date the file was generated, the client’s login name, visitor counters, or selecting alternative text based on the HTTP headers of the request. This means that web applications on the other end of the wire from the web browser is a web server. The web server is the entry point to the Middleware Layer. The purpose of the Middleware Layer is to accept incoming requests and process them, using the resources provided by the web server, the machine that the web server runs on, or by the network of servers and resources that the web server is connected to.
For example, one of the most basic functions of a Web server is distributing HTML files. In this case, a web browser requests a given HTML file from the web server. In response, the web server will find the given file on the local (or networked) file system and send it back to the browser. The web server has at its disposals a whole world of resources beyond file systems. Web servers are in close contact with all sorts of resources including data stores, applications, business objects, operating system resources, authentication services (server-based or directory services like LDAP/ADSI) and more.
Although Server Side Processing has many advantages, it also has some disadvantages. For example, the useful things done with SSP are static, and can be generated when a document is generated. Parsing a source document once to generate the documents actually served will use much less CPU than parsing the document every time it is served. To select between documents, having the server select between static documents takes much less CPU than parsing the HTML as it passes through the server. Furthermore, SSP doesn’t work with caches.
If a document is cached, users start seeing the wrong version of the document. For the cases where the document is not cached, it must be re-fetched – even if unchanged – for every load. This increases the network load across the entire network. And because the average end-user bandwidth goes down instead of up, this is quite a disadvantage. In conclusion, SSP appears to serve no useful purpose which pre-processing documents cannot provide. Further, it causes both extra CPU usage on the server and extra bandwidth usage on the entire network while doing so.