EMERGING TRENDS IN SOFTWARE ENGINEERING
CLOUD COMPUTING
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
No downtime
|
|
|
Unavailable for potentially five minutes a day
|
|
|
Unavailable for potentially five minutes a month
|
|
|
Unavailable for potentially five minutes a year
|
Detailed explanation-1: -The accepted availability standard for emergency response systems is 99.999% or “five nines” – or about five minutes and 15 seconds of downtime per year (see table below). To achieve five nines, all components of the system must work seamlessly together.
Detailed explanation-2: -The five nines standard originated in the telecom industry as a part of an effort to minimize downtime. 99.999% availability indicates that an environment will have five minutes or less of downtime per year (see Table A). Achieving five nines availability involves removing all single points of failure from a system.
Detailed explanation-3: -4 9s (99.99%) scenario. This availability goal for applications requires the application to be highly available and tolerant to component failures. The application must be able to absorb failures without needing to get additional resources.