Web Cache (HTTP Proxy Server)
Web caching is being done to reduce the use of bandwidth, the load on the server and prevent lag. Hence, a web cache stores various copies of documents that are passing through the computer system. Through web caching, the Internet experience can be improved for more people.
There are two kinds of web cache—a proxy cache and a browser cache. Most web browsers such as Internet Explorer and Mozilla Firefox possess web caches. The browser usually stores a copy in the local system of the pages recently accessed by the computer system. When the user goes back to the pages recently visited, instead of accessing the copy of the pages from the Internet all over again, the system will use the pages stored in the local system.
A proxy cache, on the other hand, resides in a shared network. Because the proxy server handles a number of transactions as directed by the end user, it also stores local copies of the recent pages visited by the user. Any request from the user to visit the same pages will result in the cache being activated. This means that the system becomes more efficient as it will no longer have to download all of the materials already downloaded from the source of the content.
A browser usually takes the name of the host and then converts this to an IP address. An HTTP (HyperText Transfer Protocol) session is recorded against that address. Subsequently, the system then retrieves the URL based on the instigation of the user. With the use of proxy cache, the process is not altered much—the URL request will be directed to the proxy cache. The URL of the file of the proxy cache will be compared with that of the original URL to ensure freshness and to prevent expired pages to be displayed. When the server validates the content in the proxy cache, then it becomes labeled as fresh again.
Through the use of web caches, the bandwidth will not be overloaded and efficiency is ensured in the system. If the system of the user has to download every single thing from the server being accessed, then the process would be more tedious and inefficient. Yet, with web caches, this process can be made more efficient, thus ensuring the better experience for the end user.
Content Distribution Network
A content distribution network (CDN), also known as the content delivery network is a connection of computers on the Internet. These computer systems are connected together for the purpose of delivering content with the intention of cost efficiency and improved performance to end users. It is also undertaken for the purpose of scalability.
CDN focuses on the acceleration of web performance. This kind of network focuses on the interaction between the end users and the hosts. The network at the center of the CDN tends to be simple and optimized toward the forwarding of data packets. CDNs empower the quick distribution of data by establishing several applications in different locations on the Internet to help optimize the delivery of content on the web. A CDN normally uses various web processes such as server load balancing, content services, request routing and even web caching to augment the end-user experience.
While web caching is being done at the level of the user, it can also work towards the establishment of CDNs for better web performance. Server load balancing, on the other hand, uses around 4-7 switches—web or content switch and multilayer switch to distribute traffic among several web caches or servers operating within the network. With this kind of arrangement in place, the switch has only one virtual IP address. When traffic gets directed to the switch, it gets directed to a web server already connected to the switch. With this, the servers and web caches can then share the load, thus ensuring better connection and service for the end users. Should a web server failed, the other servers can still handle the load and will provide fewer distractions to the users.
Request routing forwards the requests of end-users to the source of the content with the best capability to address the request. It would be logical therefore to forward a user’s request to the closest service node. If that fails, the request will then be forwarded to the node with the largest capacity. To facilitate this kind of request direction, several algorithms are being used. The simpler CDNs should be setup by manually copying asset. CDNs used to rely heavily on load balancers and web caches. Contemporary ones, however, use servers and CDN management technology that distributes assets effectively and dynamically.
Peer-to-peer (P2P) platforms is an example of CDN technology. P2P is being used to send content to users who request such services. The good thing about P2P is the low cost of using it and the efficient means in which it distributes content. Yet, the contemporary feature of P2P, as opposed to traditional CDN, is the way in which a user can upload content as opposed to downloading it only.
Web cache whether in the local computer of the user or in the proxy server is used to reduce the load of internet connection and make the user experience better and more efficient. It does not extend beyond the proxy server. A web cache also does not use the cache of other computers connected to the network. This is what CDN can do. It can use multiple web cache from a number of computers that are connected to the network to reduce load and make the internet connection more efficient. While CDN uses web caching, it also uses a number of other tools and application in order to distribute load and make the connection more efficient and work for the benefit of all the users connected to the network.
HTTP and FTP
Hyper Text Transfer Protocol (HTTP) is used for communicating and retrieving linked text documents. HTTP is essentially used by a client to communicate to a server. Whenever a client makes a request through HTTP such as typing an URL on the browser,, HTTP will then contact the origin server. This process is more complicated than it sounds because before the user’s request arrives at the server, the request shall have gone through several proxy servers and gateways. Although TCP/IP is perhaps the most popular application on the internet, HTTP can be used on any protocol or network on the Internet.
File Transfer Protocol (FTP), on the other hand, is used by a client, most of the time a web administrator, to transfer files from a computer to another through a network, usually, the Internet. This protocol is used in handling files among computers connected by TCP. Through an FTP server, a user can upload, download and manipulate files to the server. FTP is usually used for uploading content that is meant to be distributed among various users. An FTP software is needed in order to connect to an FTP site.
HTTP is usually used by the receivers of data or files over the Internet. FTP, on the other hand, is being used by webmasters in order to upload files to servers that can be accessed by end users. The files that could be accessed via HTTP are usually uploaded and manipulated through FTP. While users may visit a website such as www.yahoo.com, the data, files, and programs controlling the website may be accessed and manipulated through FTP.