E-Portal -Paraphrase - Price is NOT Negotiable

IT405

Instructions:

· This Assignment must be submitted on Blackboard (WORD format only) via the allocated folder.

· Email submission will not be accepted.

· You are advised to make your work clear and well-presented, marks may be reduced for poor presentation. This includes filling your information on the cover page.

· You MUST show all your work, and text must not be converted into an image, unless specified otherwise by the question.

· Late submission will result in ZERO marks being awarded.

· The work should be your own, copying from students or other resources will result in ZERO marks.

· Use Times New Roman font for all your answers.

Student Details:

Name:

CRN: 21623 ID:

College of Computing and Informatics

Question One

1 Mark

Learning Outcome(s):

Understand the key elements of portals development

Define the following terms:

Deployment of website

Deploying means getting the website files onto the server. For web sites that are more complicated, it involves creating and running the necessary scripts to keep the web server up to date with the correct version of each programming language and framework. A web farm is a cluster of multiple web servers that running the same copy of code, serving the same web site to distribute traffic among them in a load-balanced environment. We use a hardware load balancer or implement Network Load Balancing (NLB) for Windows to make several web servers respond to a fixed IP.

Web hosting

Web hosting is the activity or business of providing storage space and access for websites; a reasonable web-hosting configuration should include two web servers, two database servers, a load balancer, and a firewall. It is the minimum needed to guarantee 95 % uptime.

Question Two

1 Mark

Learning Outcome(s):

Understand the key elements of portals development

.

What are the types of web caching? Explain each type in detail.

Types of web caches are Browser, Proxy and Gateway.

The browser cache is the fastest one of all because the response is stored right on the computer. All modern browsers have limited storage dedicated for cache, usually about 100 MB, that means the browser can store 100 MB worth of data locally on the user’s computer and not request it again from the origin server. However, we need to store only critical information that we access frequently and takes time to download.

Proxy cache known as a type of shared cache, meaning if we have number of users coming from the same proxy, the content is delivered to the proxy from the origin server just once for the first user hitting the site. The proxy server will serve the content directly for the other users, although it may be their very first visit to the site.

Gateway cache set up by webmasters in the user’s network and the origin server. They are not part of the production environment nor are part of end user’s network. They work as intermediaries between user “Or proxy servers” and origin server.

Question Three

1 Mark

Learning Outcome(s):

Understand the key elements of portals development

Explain the meaning of memory leak, How it effects the client-side performance?

Memory leak states a failure in a program to release discarded memory, causing impaired performance or failure. Due to heavy JavaScript usage in Ajax sites, browsers suffer from performance degradation and memory leaks. That happen when IE’s DOM not managed by JavaScript and does not understand circular references. When a circular reference arises, the garbage collector cannot retrieve the memory, so in this case we have a memory leak. We must denote that the more IE runs and leaks the slower it and other programs become. Therefore, a user must close the browser to free up the RAM that IE has allocated to return to normal speed. We can resolve the issue by removing the event handlers and DOM elements; decrease the web-service call payload, and using out-of-scope functions.

Question Four

1 Mark

Learning Outcome(s):

Understand the key elements of portals development

To avoid shutting down a website when changing the server of the website, redirecting traffic to an intermittent subdomain is required. List the steps of the redirection process?

The steps required in redirecting traffic to an intermittent subdomain are:

A user that has the old IP in their DNS cache go to the old server and redirected to the new server.

In time, inheritor DNS cache is refreshed and they get a new IP.

Their requests go to the new server and no required redirection.

After 4 to 5 days, a user can safely bring down the old server.