Block 4 Revision All Parts-1 PDF
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This document discusses the concept of downtime in computer systems and its effects on various aspects. It analyzes the primary reasons behind system downtime, and the advantages and challenges in the operations of data centers.
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QN Question Answer 1. What do we mean by The The term ‘downtime’ refers to the total time that a system is term ‘downtime...
QN Question Answer 1. What do we mean by The The term ‘downtime’ refers to the total time that a system is term ‘downtime’? unavailable for use. Every hour of downtime can cost an organisation a lot of money. What sort of actions or behaviours lead to downtime? Before I discuss my findings, see what you can find out by searching the Weber 2. What are the main causes of The majority of downtime is downtime? The result of planned maintenance and upgrades. results are from planned, unavoidable activities such as data backups, database reorganizations and hardware and software upgrades. 3. What is the effect of In today’s e-‐business, systems must be available 24/7. downtime on today’s e-‐ Downtime can hurt a business because business? information is not available, decisions are not made, orders are not shipped, funds are not transferred and customers cannot interact with the organization in short, business stops. 4. Arnold suggests that all 1. Backup and restoration downtime can be broadly 2. Hardware, network, operating system upgrades classified under seven 3. Batch processing transactions headings, List them. 4. Application and database maintenance 5. Environmental factors 6. Application errors 7. Operator and user errors 5. What is the main idea of data The majority of small-‐ and medium-‐sized companies outsource centers the provision of computers and networks to commercial data centers; large warehouses containing several thousand servers, special cooling equipment, backup generators and multiple suppliers of power and internet access. 6. What is the main advantage These data centers can spread the cost of the specialized of data centers? equipment and staff across all the servers and incorporate disaster recovery techniques to safeguard customer operations. 1 7. What are the main causes of 1) UPS system failure (includes battery failure) downtime in data centers? 2) Accidental/human error 3) Internal environmental control 4) Weather 5) Standby generator failure 6) IT equipment failure 8. Define Reliability. The ability of a system or component to perform its required functions under stated conditions for a specified period of time. 9. What is The ‘mean time to The ‘mean time to failure’ (MTTF) is a statistical measure of failure’ (MTTF)? reliability for items that cannot be repaired. It is based on testing a batch of items over a short period of time, where ‘short’ is taken to mean short when compared to the expected life of the item 10. How to calculate the mean time to failure (MTTF) is: 11. If a disk drive manufacturer tests a sample of 1,000 drives by running them for a period of 1,000 hours (just over 41.5 days). At the end of that period one disk drive was found to have failed. Calculate The MTTF. 12. How do we calculate The Annualized failure rate (AFR) 13. If a disk drive manufacturer The factor 8760 is the number of hours in one year. tests a sample of 1,000 drives (MTTF of 1,000,000 hours) the AFR = 0.876%. by running them for a period of 1,000 hours (just over 41.5 days). At the end of that 2 period one disk drive was found to have failed. Calculate The AFR. 14. How can we use the AFR to as follows: estimate the performance of Number of drive failures = number of drives x AFR. the disk drives in a server For example: farm? If there are 2000 disk drives we can expect 2000 × 0.876, or approximately 18 drive failures per year. 15. What is the main problems One of the problems with MTTF and AFR is that they represent with MTTF and AFR statistical values obtained from special test set ups, so they share little in common with the average computer. Furthermore, attempting to calculate the MTTF value for a computer from the MTTF data of the individual components is not a simple task. 16. Define Availability. Availability is the probability that a service or system is available to be used; it is fully functional, performing with specified limits, and delivering the appropriate level of quality. 17. Define Availability From a is the probability that a system is working when required. user’s perspective 18. How do we calculate Availability? 19. How do we calculate Availability If a system has not yet been built 20. What is Operational Operational availability (Ao) is another version of availability, availability? which is a measure of the availability actually measured for a real system 21. How do we calculate Operational availability? 22. What is the mean downtime The mean downtime (MDT) accounts for all the time the (MDT? system is unavailable, no matter the cause. It will include downtime for corrective maintenance (fixing a problem), preventative maintenance (change a noisy fan, software update), and human errors. 3 23. What is Load sharing? Load sharing is intended to improve availability by sharing the total workload across a number of computers. 24. What is Load sharing in the In the case of a web application the ‘nodes’ would be web case of a web application? servers, each with its own local storage for operating system, web server, content, and application data, and the combination of nodes and monitor is referred to as a ‘web server farm’. Other applications might comprise multiple file servers, print servers, DNS servers; hence use of the generic ‘node’. 25. What is ‘round-‐robin’ The ‘load sharing’ monitor provides a single global IP address scheduling? for the web server farm and communicates with the individual web servers over a private IP network. The monitor’s primary function is to decide the allocation of requests amongst the member nodes based on how busy each node is, or it may be a simple rotating sequence (also known as ‘round-‐robin’ scheduling). 26. How the monitor is The monitor is represented by another computer with represented and what should appropriate software, but it could also be a smart network it do? switch or router. The monitor must track the health of each node, either by observing the flow of messages, or by sending a ‘ping’ request and waiting for the response. 27. What are the solutions for One solution to the user data problem is to incorporate handling the situation of a cookies into the application so that the data is held by the node that fails after client’s browser and returned to the web server with every completing a single user request. request? Another solution is to add some form of shared storage to the architecture 28. How to overcome the To overcome the limitations of the basic configuration requires limitations of the basic that the nodes are more tightly integrated and somehow configuration of the nodes of share their current state across the entire farm. One solution is load sharing? to link the nodes together by means of a dedicated ‘heartbeat’ network and a special heartbeat monitor. 29. What are the additional costs The higher availability of the heartbeat configuration comes that come with the higher with additional costs: availability of the heartbeat dual network interfaces in each node; one for 4 configuration? application data and one for the heartbeat An additional computer to function as the heartbeat monitor. 30. Why does simple load sharing Simple load sharing offers limited availability gains because of offers limited availability the independence of each node. gains? The application will continue to function with multiple node failures, failed node will perceive zero availability 31. What do we mean by ‘scaling The real benefit of load sharing is what is termed ‘scaling out’; out’ the ability to process more requests by the simple addition of an extra node. 32. Why does Load sharing can Load sharing can reduce planned downtime because a single reduce planned downtime? node can be updated, or backed up, in isolation while the application continues to run on the other nodes. 33. What is Cluster? A cluster is a collection of independent computer nodes that function as a single ‘logical’ server to the user. 34. What does Cluster allow the Cluster allows one node to take over a running application node to do? without the user being aware that such a takeover has occurred. 35. What is the primary goal of The primary goal of a cluster is to increase availability by Cluster? means of redundant nodes. 36. Clusters typically operate in In the active-‐passive configuration one node is actively dealing two forms, with application requests; this is the ‘active’ node on the left, active-‐passive and labelled System A. The other ‘passive’ node, System B, is in a active-‐active. standby state ready to take over in case of failure. Each node is aware of its current role in the cluster, ensuring that only System A responds to client requests. 37. How the two forms of Heartbeat messages are exchanged between the active and clustering interact? passive nodes to provide the monitoring function. Application data that is written to Disk A is continuously replicated to Disk B to ensure no loss of data should System A fail. Failure of the active node forces the passive node to assume responsibility for running the application through a process referred to a ‘failover’. 5 38. What is the additional cost The gains of clustering come with additional costs: that come with Clustering? Dual network interfaces in each node, one for application data and one for the heartbeat Special software to support the clustering function and failover Extra system administration work to install, configure, and monitor the cluster High cost of removing single points of hardware failure (power supplies, disks, networks, etc.). 39. Explain briefly the concept of One of the strategies adopted by organisations that require fault tolerance. continuous availability is fault tolerance, whereby a system is designed so that it will continue to operate in the event of a single hardware failure. The general technique is to design the system with redundant elements and extra hardware such as dual power supplies, dual network interfaces, and RAID disks. 40. What do mean by The techniques for increasing availability are based on the Virtualization? traditional deployment model of one application per server farm or server cluster. Combining these techniques with the typical 3-‐tier architecture of a business application requires a lot of equipment. This is a very expensive deployment model in terms of computing equipment, floor space (or rack space), cooling equipment, power consumption and personnel. 41. Explain briefly the term The term used when multiple server applications are Infrastructure consolidation virtualized to run on a single hardware platform. So instead of two physical computers, one to host a file server another to host a print server, two virtual servers are created to operate as guests on a single computer. Infrastructure consolidation is the main contributor to reducing the total cost of ownership for business applications. 42. Explain briefly the term The term used to isolate applications for testing or to enforce Sandboxing? a high level of security. An untrusted application can be combined with a guest OS and executed within a virtual machine with the benefit of the additional protection afforded by virtualisation. 6 43. What do we mean by Legacy Many virtualisation solutions support operating systems, and systems? hence applications, that cannot be executed on newer hardware platforms. It may also be possible to emulate older peripherals that are no longer manufactured. 44. Explain briefly Recovery in an image of a virtual machine can be quickly restarted or virtualization. migrated from one virtual/physical computer to another very quickly. Most of the commercial virtualisation products support automatic restart or migration in the event of virtual server failure. 45. Explain briefly Testing and By combing the features of sandboxing and recovery it is debugging in virtualization possible to create test configurations, take images of the configuration at different stages of testing, and revert to a saved configuration in the event of a fault. 46. Explain briefly the concept of There is considerable talk about ‘cloud computing’ as the Clouds? solution to provide a rapid or agile response to the changing business environment. In a period of quick growth additional computing resources (computers, storage or network) can be brought on stream with minimal delay. If business requirements change then a new application can be brought into play. 47. Explain briefly the concept Infrastructure as a Service (IaaS) provides a business with a Infrastructure as a Service complete set of computers (servers, firewalls, load monitors), (IaaS). network links and storage devices on which to host their own software. It is up to the business to install, update, and generally manage everything. The costs are typically based on the physical equipment utilised. 48. Explain briefly the concept Platform as a Service (PaaS) offers a business a computing Platform as a Service (PaaS) platform, typically a virtual server and guest OS, on which they can run their applications. The costs are typically based on the resources used, such as the proportion of the processor utilisation, the amount of data stored on disk, or the number of bytes transmitted across the network. 49. Explain briefly the concept Software as a Service (SaaS) provides a business with an entire Software as a Service (SaaS) application, such as an email service for all employees. 7 In this model the business relinquishes control of where the computing equipment is located, what operating system is used, or where data is stored, but pays a fixed monthly charge for each user. 50. What do we mean by Disaster Disaster Recovery (DR) means putting in place a plan that will Recovery (DR)? enable a company to recover its IT systems following a disaster, or enable the systems to continue functioning during a disaster. 51. What are the causes of the The cause of the disaster disaster? may be environmental (flood, earthquake, or hurricane), equipment failure, loss of power or communications, or a security incident that prevents normal operation. 52. What is the primary goal of The primary goal of the plan is to reduce the impact of a the disaster recovery plan? disaster and to restore all systems and applications to a fully functional state as quickly as possible. Given the available technology it is possible to design an IT solution that would exhibit no loss of function and no loss of data, but the costs would be very high. 8 Block 4 Part 2 Revision QN Question Answer 53. Define the term Project. A temporary endeavor undertaken to create a unique product, service, or result. 54. Explain briefly the A new field of study is Project management, with its own set of concept of Project tools and techniques such as Gantt charts, PERT (programmed management. evaluation and review technique), and work breakdown structure. 55. Discus projects in terms Opportunities and risks. of opportunities and The opportunities might be linked to launching a new product, or risks. creating a new web application. By undertaking the project the business hopes to increase revenue, become more efficient, and make a profit. At the same time the project presents the business with risks because it may not be completed on time, it may cost more than estimated, or it may not produce the desired result. 56. What are the common The common features of IT failures. features of IT failures? 1. A lack of end-‐user involvement 2. Long or unrealistic timescales 3. Vague or inadequate requirements 4. Poor change management 5. Inadequate testing throughout the project 57. Explain briefly the Good project management strives concept of The project to find a balance between a project’s requirements and plan. quality on one side and the resources, time, and risks on the other. The proposed solution is typically expressed in the form of a project plan that documents what is to be done, who will do it, and when it will done. 58. Draw a diagram that The Waterfall lifecycle model known as linear software shows the stages of the development cycle’ each phase must be completed before the next Waterfall lifecycle model. phase can commence 9 QN Question Answer 59. Write three of the Pros Pros (advantage) and Cons of the Waterfall 1) Time spent in the early phases reduces the chance of errors lifecycle model. in later phases 2) Promotes a top-‐down approach to decomposition leading to sub-‐goals that can serve as project milestones. 3) Provides clear boundaries between phases that are orderly and predictable. Cons (disadvantage) 1) Reliance on documentation outputs at each phase can hinder communication and lead to slow development. 2) There is a long delay between the start of a project and the delivery of functional software. 3) Sequential phases restrict opportunities for parallel development. 60. Explain briefly the The V-‐model: V-‐model 1. Phases can overlap at the edges 2. All testing activity has been pulled out into a separate sequence of phases. 3. The phase ‘detailed design and production’ has been split into three phases: design, code, and test. 4. The phases after ‘production’ are bent upwards to create the V-‐shape; creating the separate lines of activity labelled ‘project definition’ and ‘project integration’. 10 QN Question Answer 61. Define a project plan. A formal, approved document that defines how the project is executed, monitored and controlled. 62. What is the main aim of The project plan aims to define : project plan? the objectives of the project and the process by which the work will be managed and delivered on time and within budget. 63. What are the main The purposes of project plan are: purposes of project plan? 1. The project objectives 2. The scope 3. Partnerships 4. The outputs 5. The resources 6. The team. 7. The estimate 8. The risk assessment. 9. Other elements: quality goals, Channels of communication 64. Discuss the importance Goals and targets of projects must be monitored to ensure that the of Projects Monitoring. project gets completed on time and within budget 65. What do we mean by Such as the delivery of an item of equipment or completion of Project milestone? some tests, and provides the means to compare the actual performance to the planned performance. 11 QN Question Answer It is to leave some time to take corrective action in case of any problems. 66. What do we mean by A project gate (or stage gate) represents a point in the project when Project Gate? all work stops to await a decision, I say yes or no for example a gate at the end of the user requirements phase provides the opportunity to terminate the project if the user requirements cannot be adequately defined. Another use of the project gate is at sign-‐off points, when the ‘client has to confirm their acceptance of some output. 67. What are the common The three most common metrics employed are: metrics employed to 1. Time: compares the estimated duration to the actual time taken monitor projects? to complete a work package. 2. Cost: compares the estimated cost to the actual cost of completing a work package 3. Deliverables: compares the estimated time and cost to create a deliverable with the actual time and costs. 68. Explain briefly the Gathering Gathering stage of The gathering stage is intended to elucidate the raw ideas about requirement. what the ‘solution’ should provide in terms of important features and how it will interact with other parts of the business. 69. Explain some of the One of the techniques employed is to interview stakeholders about techniques of Gathering? their specific needs. If the objective of the project is to improve an existing process, then it is important to understand how the current process operates and where it falls short of user’s needs. 70. Explain briefly the The refining stage converts the raw ideas into something more Refining stage of structured, such as a business process or a prototype website. requirement. It is important that stakeholders are given the opportunity to review the proposal to ensure it meets their needs. Ideally, stakeholders should ‘sign off’ on the requirements in order to lock down the set of features to be provided. 71. What are the main the One of the challenges of the user requirements phase is satisfying challenges of the user conflicting features or functions. Individual stakeholders will have requirements phase? different perspectives on what the project should achieve and hence what the priorities should be. 12 QN Question Answer 72. Explain briefly MoSCoW MoSCoW prioritisation. The acronym ‘MoSCoW’ represents four prioritization concept. levels of priority expressed by the words ‘Must’, ‘Should’, ‘Could’, and ‘Won’t’. The claimed value of the MoSCoW method is that the use of words offers a clearer meaning to stakeholders when they come to prioritise features and functions 73. Explain briefly the Must – the project must provide the feature or function; a ‘Must’ MoSCoW’ levels. feature is non-‐negotiable and if not delivered then the project is a failure. Should – the project should provide the feature or function if at all possible; a ‘Should’ feature is important, but if time is short, it could be postponed for a future delivery. The project still has value without these features. Could – the project could provide the feature or function if it does not affect anything else; a ‘Could’ feature would be useful to have if it does not cost too much or take too long to develop, but it is not central to the project. Won’t – the project won’t provide a feature or function this time, but will be needed in the future, where it may be upgraded to a 'Must'. Knowing what the future features and functions are helps to ensure that a proposed solution does not preclude them. 74. Explain briefly the term ‘functional quality’, meaning that a piece of software is ‘fit for ‘functional quality’. purpose’ and delivers the functional requirements. Some texts use the term ‘external quality’ to refer to quality ‘external quality’ characteristics seen by an external user. The primary method of assessing functional, or external, quality is by testing that the software fulfils each of its requirements. 75. Explain briefly the term Another interpretation of quality is of ‘structural quality’ or ‘structural quality’ ‘internal quality’ that relates to how well the software was ‘internal quality’ produced. 76. List the characteristics of (ISO) describes software quality in terms of eight characteristics : software quality which 1. Functional suitability, are described by ISO. 2. Performance efficiency, 3. Compatibility, 13 QN Question Answer 4. Usability, 5. Reliability, 6. Security, 7. Maintainability, 8. Portability. 77. List the Consortium for IT The Consortium for IT Software Quality (CISQ) has defined five Software Quality (CISQ) structural quality attributes essential for a piece of software to have structural quality business value attributes that are 1. Reliability essential for a piece of 2. Efficiency software to have business 3. Security value. 4. Maintainability 5. Size 78. List the points that the quality plan address the following points : should be addressed in 1. identification of appropriate quality standards and the the quality plan methods to satisfy them 2. procedures to ensure quality standards are followed and identification of those responsible for quality assurance activities 3. monitoring of project outputs to determine compliance with the quality plans and to provide opportunities for improvement. 79. List standards and tools In the case of web applications there are numerous standards and that can contribute to tools that can contribute to quality. quality of web For example, the W3C standards for HTML and CSS and the WCAG applications. guidelines can be combined with output from validation tests that acts as evidence of compliance 80. What are the methods The resource and duration estimates can be derived using the that are used in the methods listed below: resource and duration 1. Use historic data: look back at similar tasks and use the time estimation of projects it took as the estimate for the current task. Many companies collect data about performance for just this purpose. 2. Ask a friend: asking a co-‐worker is a good option when the task is unfamiliar to you. 3. Weighted average: include three estimates labelled ‘best’ ‘worst’, and ‘most likely’. These three are combined as (best + 4 × most likely + worst) ÷ 6 to give the desired value. 4. Management tax: once your estimate is obtained increase it by a fixed percentage to allow for non-‐productive activities such as meetings, phone calls, email, etc. 14 QN Question Answer 81. Explain briefly the term Projects have some degree of uncertainty as to the outcome, for Risk management. example, Will it be completed on time and on budget and will it fulfill the requirements? Understanding and controlling this uncertainty is termed risk management and it involves putting in place procedures to help identify and assess project risks, along with strategies to minimize the impact of any risks that arise. 82. What are the two main There are two important points to observe. important points to The first is that a specific risk may not materialise, for example, it is observe in Risk possible that all testing is completed even though there was a risk management. that some testing would be delayed or skipped. The second point is that the consequence of a risk may not have a significant impact on the project, for example, progress in the latter stages of development may recover lost time as the team develop their knowledge of the development tools. 83. List the strategies that There are several generic strategies that could be employed such as: could be employed in Risk Management. 1. Eliminate or avoid the risk by not doing things or doing them a different way 2. Reduce the likelihood of the risk 3. Reduce the impact of the risk 4. Stop the project 5. Share the risk with a partner 6. Accept the risk 84. What is the final stage of The final stage of risk assessment is to combine all the information risk assessment? that has been gathered into a risk management plan that highlights the most significant risks, outlines the mitigation strategy, and assigns responsibility for monitoring the risks. 85. Explain the term risk It is a separate document, known as the risk register, is used to track register changes in the level of each risk and to record actions are taken to manage the risks as the project progresses. 15 Block 4 Part 5 Revision QN Question Answer 86. What do we mean by Testing has become a core element of web application System testing? development and it is the mean by which we demonstrate that the solution fulfils the requirements and that we have exercised due diligence in its creation. 87. List with explanation what to test in the system. 1. Functionality testing: aims to verify that web pages are functional. 2. Usability testing: aims to ensure that the application is easy to use 3. Accessibility testing: aims to ensure the application is accessible to all users 4. Interface testing: aims to ensure the correct interoperation of the web, application, and database servers. 5. Compatibility testing: aims to ensure that the application functions correctly regardless of browser, operating system, or hardware type or version. 6. Performance testing: measures the ability of servers and network to respond to user demand. 7. Security testing: aims to ensure the application implements authentication and authorization controls and is not vulnerable to attacks. 8. Regression testing: is any type of software testing that seeks to uncover defects that recur as an unintended consequence of program changes; the software is said to have regressed to the previous defective state. 88. Explain briefly the role of V-‐model lifecycle provides a useful framework to explore the V-‐model in testing. management of testing. The left-‐hand part of the V-‐model corresponds to the design of the application, expanding on the level of detail within each phase of definition. 89. What is the importance of The creation of tests plans is an integral part of project definition creating tests plans? that provides verification of the design and helps to ensure an application fulfils its requirements. 16 QN Question Answer 90. What is required to mange Managing each phase of testing requires: each phase of testing? identification of what is to be tested, who does the testing, and how the results of the tests are collated and communicated. 91. Who is supposed to Large projects often have a dedicated test team who prepare and conduct the testing? execute the tests and track defects. Smaller projects typically share the work amongst the development team. 92. What is the main role of Unit tests are intended to verify the execution of small pieces of Unit test? code, such as functions or object methods, before the function or object is combined with other units into a larger functional element. 93. What are the main points or a typical web application the unit test phase should cover the that can be included in following items: Unit test for a typical web HTML validation application? CSS validation Forms (as components combining multiple units) Internal hyperlinks Client-‐side objects and functions (data validation) Server-‐side objects and functions Database queries. 94. Can the author of the unit The author of the unit should not prepare the tests or execute prepare the tests or them; to avoid any tendency to bias the test toward the known execute them? features of the unit. 95. What is the main role of Integration tests are intended to verify that individual units work Integration test? together, which for the typical web application means testing functionality, usability, browser compatibility, and accessibility. 96. What is the main role of Usability tests are conducted to identify any design Usability test? inconsistencies or usability issues in the user interface and content areas of a website’s pages. 97. Explain briefly the potential Potential sources of error may include: sources of error when Navigation errors – a user fails to locate functions, takes conducting Usability tests. too many keystrokes to complete a task, or fails to follow the recommended sequence of web pages. Presentation errors – failure to locate important 17 QN Question Answer information on the page, failure to select the correct action due to labelling ambiguities. Control usage problems – incorrect use of buttons, tabs and toolbars, or failure to enter data into the correct field. 98. What is the main role of Functional tests are typically designed around specific tasks, Functional test? such as user registration, catalogue search, or payment for goods and will highlight integration problems between the client and server. 99. What are the main role of System tests, or end-‐to-‐end tests, are intended to verify the System tests? interoperability and performance of the application in its final configuration and to verify integration with other hardware and software systems that support the wider business functions. It provides the opportunity to verify and document the procedures to install and configure servers, set up user accounts, populate the database with test data-‐sets, and test backup and recovery procedures. 100.Where should we conduct Ideally system tests are conducted on a dedicated set of system test? equipment that matches the performance and configuration of the final production servers. 101.When should we conduct By the time system testing commences all Unit and Integration system test? testing should be complete to the point that there is a stable version of the web application to test 102.What a re the goals of Once a stable configuration of the test environment has been performance test? created performance testing can commence. The goals of performance tests is to establish: That the system meets planned response times for a given load That the system remains stable under high load An estimate of the sustainable peak load 103.What d o we mean by the Where the term ‘load’ represents the number of simultaneous term “LOAD “ when we users accessing the web application. talk about high load or peak load? 104.Explain briefly with Load test: example the load test. Describes a performance test during which a well-‐defined load is 18 QN Question Answer applied to the application to determine the response time for individual functions. For example, the requirements may specify that with a load of 300 users the response time to a log-‐in request should not exceed 10 seconds or that a search for a product within a catalogue should not exceed 15 seconds. 105.Explain briefly Stress Stress test: test and its main goal. Describes a test to assess the performance of the application when the load exceeds the expected usage. The goal is to ensure that the system remains reliable and stable even though errors may arise, such as dropping a user part-‐way through a purchase transaction. 106.Explain briefly Capacity Capacity test: test. Describes a performance test intended to provide an estimate of the maximum number of users the application can support reliably. 107.How do we conduct During the test the load is increased until the performance Capacity test? becomes unacceptable; either because the response times become excessive or the server’s processor utilization exceeds a predetermined limit. 108.Explain the goals of Acceptance or user acceptance testing is the final phase of testing Acceptance or user in the V-‐model lifecycle. acceptance testing. The goal of this phase is to verify that the web application fulfils the ‘user requirements’ that were established at the outset of the project and thereby reduce customer dissatisfaction because the application doesn’t do what was promised. 109.Who should conduct the It is the client, not the developer, who should perform the acceptance test? acceptance tests against the test environment. 110.What a re the critical Critical areas for client involvement are: areas for client Function: (Application fulfils functional requirements) involvement in testing. Usability: (User can get to information quickly and easily, on-‐screen instructions are understandable and number of steps to complete a task is appropriate) Work flow: (Sequence of web pages of an application match the underlying process work flow (e.g. the steps are in the correct order). 111.What is the difference Once all the tests have been identified they must be executed and between Manual or the outcomes recorded. 19 QN Question Answer Automated testing? manual execution: a user sits in front of a computer and enters data, search terms, or follows hyperlinks and records the Tow type of testing outcome of each test. Manual Automated The alternative is automated execution whereby a program or script runs a number of predefined tests and saves the results. Such as whitebox, blackbox. Knowing the best way to perform the tests can be as important as the tests themselves. 112.What d o we mean by Test Test environments means the configuration of clients, servers, environments? and network used to conduct the tests. Three distinct environments are required namely: Development, Test, and Production. 113.What d o we mean by the The development environment is a mixture of clients and servers development that will support developers during the early phases of the environments? project. Unit testing and version control is the responsibility of each developer. 114.What is the use of Version Version control will store all the code, tests and documentation control? associated with each project. 115.What is the use of Access Access controls ensure that each develope