C90-03A最も有効な質問と解答で勉強

Cloud Service A is being made available on public Cloud X by Cloud Provider X via the SaaS delivery model. Cloud Service A is hosted by Physical Server A that also hosts cloud services being used by different cloud service consumers (and owned by different cloud service owners).
Cloud Provider X needs to make Cloud Service A available to a new group of cloud service consumers, but must do so without the increase in usage volume affecting Cloud Service Consumers A and B.

Which of the following statements does not accurately describe a solution (or a set of solutions) that addresses this requirement?

• A. Cloud Provider X can scale up Cloud Service A by upgrading the Physical Server A hardware to increase the server'sprocessing power. Cloud Provider X can scale out Cloud Service A by adding redundant implementations of the service and by using the automated scaling listener mechanism.
• B. Cloud Provider X can upgrade its infrastructure by increasing its ability to horizontally scale IT resources that are used by Cloud Service A. Cloud Provider X can upgrade its infrastructure in order to vertically scale IT resources that are used by Cloud Service A.
• C. Cloud Provider X can upgrade its infrastructure to increase the cloud's ubiquitous access characteristic. This will enable the cloud to provide distributed failover for IT resources across multiple devices in order to increase its ubiquitous resiliency. To achieve this, Cloud Provider X will further need to implement the failover system, state management database and resource replication mechanisms.
• D. Cloud Provider X can scale out Cloud Service A by implementing new cloud computing mechanisms, such as the virtual server and resource replication mechanisms, which can enhance the cloud's elasticity characteristic.

Cloud Provider Y owns Cloud Y, which provides a set of cloud services, virtual servers and one physical server. Cloud Services A and B are hosted on Virtual Server A, which is hosted by Physical Server A. Physical Server A also hosts Virtual Server B, which hosts redundant implementations of Cloud Services A and B for load balancing purposes. Cloud Service Consumer A is accessing Cloud Service A located on Virtual Server A. Cloud Service Consumer B is accessing Cloud Service B located on Virtual Server B. Cloud Service Consumers A and B are both owned by Cloud Consumer X.
Cloud Consumer X has recently complained that Cloud Services A and B have become less available than what is guaranteed in their service level agreements (SLAs). Cloud Provider Y launches an investigation that reveals that Virtual Servers A and B have been subjected to denial of service attacks. This is confirmed as the cause of the decline in the availability of Cloud Services A and B.

Which of the following statements describes a solution that can increase the availability of Cloud Services A and B?

• A. Cloud Provider Y can implement a cloud bursting system, whereby Cloud Service A on Virtual Server B automatically takes the place of Cloud Service A on Virtual Server A when that service fails. Similarly,Cloud Service B on Virtual Server A can then automatically take the place of Cloud Service B on Virtual Server A when that service fails.
• B. Cloud Provider Y can introduce a single sign-on mechanism for Virtual Server A to mitigate denial of service threats. The automated scaling listener can then be implemented on VirtualServer B in order to limit the number of instances of Cloud Services A and B. This will prevent Virtual Server B from overloading due to denial of service attacks.
• C. Cloud Provider Y can implement the identity and access management mechanism to mitigate denial of service attacks and can further implement the failover system mechanism (by introducing a redundant physical server with redundant virtual servers) so that when an attack is successful on a given virtual server, a redundant virtual server can take its place.
• D. Cloud Provider Y can move Cloud Service B to Virtual Server A, thereby positioning Virtual Server B as a redundant fallback server used when Virtual Server A is successfully attacked. Similarly, Cloud Provider Yean move Cloud Service A to Virtual Server B, so that Virtual Server A acts as a redundant fallback server for when Virtual Server B is successfully attacked.

The cloud service owner of Cloud Service A is evaluating Clouds X, Y and Z to determine which cloud environment can offer the greatest level of reliability. All three clouds are geographically dispersed across three separate time zones. As a result, each cloud experiences usage peaks at different times. Based on the metrics provided, the greater the usage of a cloud, the lower its reliability. When the cloud service owner complains to Cloud Provider A (the owner of all three clouds) that none of the clouds provide an adequate level of reliability, Cloud Provider A suggests a solution that increases resiliency.

Which of the following statements accurately describes a solution that can be used to fulfill the resiliency requirements of Cloud Service A?

• A. A cloud balancing solution is established, whereby an automated scaling listener mechanism is implemented on each cloud in such a way that every cloud can automatically scale out to another cloud. As a result, if reliability problems occur on any one cloud, the subsequent requests will be scaled out to another cloud in a manner that is transparent to cloud service consumers.
• B. A cloud balancing solution is established, whereby a resource replication mechanism is implemented on each cloud. This allows Cloud Service A to be automatically replicated across cloud environments, thereby enabling each implementation of Cloud Service A to take the place of another, whenever failure conditions occur.
• C. A failover system mechanism is implemented on Cloud X, which acts as the primary point of contact for cloud serviceconsumers. Upon failure conditions occurring, the Cloud Service A implementation on Cloud X automatically hands over control of current and future message requests from cloud service consumers to Cloud Y. Cloud Y retains control of cloud serviceconsumer communication until the next failure condition occurs, at which point it hands over control to Cloud Z. Finally, if a failure condition occurs in Cloud Z. control is handed back to Cloud X.
• D. Redundant implementations of Cloud Service A are deployed in all three clouds. The failover system mechanism and a special type of automated scaling listener mechanism are implemented to establish a system whereby one redundant Cloud Service A implementation will automatically take over from another.