CSE InfoNotes

- Pass is the outgrowth of the Saas application delivery model. - Basically platform as service (Paas) provide platform for other to use. - A proper Paas provider has to take care of everything that is necessary in order to run specific language or technology stack. - Basically Paas provide a carefree environment for developers to work i.e it focus only on code without having to worry about configuration and maintenance of the underlying infrastructure. - Consider the following Paas component stack - The above fig illustrates that the cloud provider has control over the lower layer of the software stack. - The provider makes the programming and utility interfaces available to the consumer at the middle-ware layer. Key characteristics of Paas - Paas include the services to develop, test, deploy, host and manage the application. - Paas providers often include the services for concurrency management. - Another key characteristics of the Paas is to integrate with web ser

- Software as service (Saas) is a way of delivering application over the internet as service. - Instead of installing and maintaining the software, you can simply access it over the internet. - Saas application runs on Saas provider's server, where the provider manages access to the application, including security, availability and performance. - Thus, email client such as Gmail or Hotmail and many different software solution accessible over internet could be given as an example of Saas. - In order to understand the role between cloud consumer and cloud provider, refer following fig. - The above fig depicts a user level control which represent that a consumer has control over the application that made available by the Saas application. - A provider normally has significantly more administrative control at the application level. - The responsibility of provider are to deploy, configure, update and manage the operations of the applications in order to provide it to

- Cloud computing is the model for enabling, convenient, on-demand network access to shared the pool of configurable computing resources. - Basically it is the collection of integrated and network hardware, software and internet infrastructure. - It uses the internet for communication and transport hardware, software and network services to the client. - In addition, the platform provide the on-demand services that are always available anywhere to the client. - For example if you store your photos online instead of on your home computer or use web-mail or social networking sites, at that time you are using cloud service. - Cloud computing refers to the delivery of resources over the internet. - Instead of keeping the data in your pwn hard disk or updating the application for your own need, you used service over the internet called cloud service. - Cloud service allow the individual or business to used software and hardware that are managed by the third parties at remote

- Requirement elicitation means gathering of requirements. - Perhaps it is most difficult, critical, most error prone and most communication intensive aspect of software development. - The most important goal of software requirement engineering is to find out what the customer really wants. - The users need can be identify only by understanding expectation of the user from the developers. - Requirements are gathered by asking the question to user and writing down their answers and their exceptions of the software that how he want to use software. - Gathering the requirements of users is the most difficult part of the software development, because both developer and user have different mindset regarding the software. - Here, communication of both the parties are the most essential for software product. - There are number of requirement elicitation method. https://en.wikipedia.org/wiki/Requirements_elicitation   - Some people think that one methodology is alway

- Requirement engineering produces one large document, written in natural language, contain a description of what the system will do without describing how will it do. - Requirement engineering is the discipline application of proven principles, methods, tools and notations to describe the proposed system’s intended behavior and its associated constraints. - This process contains the four steps as shown in fig i] Requirement Elicitation This is also known as gathering of requirements. Here the requirements are identified with the help of customer and existing system process are available. ii] Requirement Analysis Requirement analysis     are start with requirement elicitation. Here the requirements are analysis in order to identify inconsistencies, defects, omission etc. iii] Requirement Documentation This is the end product of requirement elicitation and analysis. The documentation is very important as it is the foundation of the software. iv] Requi