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 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.
• 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 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.
• 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.

A cloud consumer is interested in leasing cloud-based virtual servers. It compares the virtual servers offered by Cloud Provider X and Cloud Provider Y.
Cloud X (owned by Cloud Provider X) and Cloud Y (owned by Cloud Provider Y) both provide shared physical servers that host multiple virtual servers for other cloud consumers.
The virtual servers on Cloud X are accessed directly, whereas the virtual servers on Cloud Y are accessed via an automated scaling listener. On Cloud X, virtual servers are pre-configured to support a specific amount of concurrent cloud service consumers. When this threshold is exceeded, cloud service consumer requests are rejected. Due to the use of the automated scaling
listener, virtual servers on Cloud Y can provide a greater level of elasticity.

The hourly cost to the cloud consumer to use a virtual server on Cloud X is half that of the cost to use a virtual server on Cloud Y.
Within a one month period, Cloud Provider X bases its hourly charge on the maximum number of virtual servers used. Within a one month period, Cloud Provider Y bases its hourly charges on actual virtual server usage. Cloud Provider Y charges $20 for each hour that a cloud consumer uses a virtual server.
The cloud consumer predicts its monthly usage requirements to be as follows: The cloud consumer is required to choose the cloud provider with the lowest on-going cost, based on its predicted usage. Which of the following statements accurately calculates the on-going usage costs of Cloud Providers X and Y and correctly states the cloud provider that the cloud consumer must choose?

• A. The total usage duration is (20 + 30 + 50) x 12 hours = 1,200 hours.
  The actual usage is (20 X 3) + (30 X4) + (50 X 5) server hours = 430 server hours.
  The cost of using virtual servers from Cloud ProviderXis12X5X$10 = $600.
  The cost of using virtual servers from Cloud Provider Y is 430 X $20 = $8,600.
  The cloud consumer must therefore choose Cloud Provider X.
• B. The total usage duration is (3 x 20) + (4 x 30) + (5 x 50) hours = 430 hours.
  The actual usage is (20 + 30 + 50) hours = 100 hours.
  The cost of using virtual servers from Cloud Provider X is (430 X $10) = $4,300.
  The cost of using virtual servers from Cloud Provider Y is (100 X $20) = $2,000.
  The cloud consumer must therefore choose Cloud Provider Y.
• C. The total usage duration is (20 + 30 + 50) hours = 100 hours.
  The actual usage is (20 + 30 + 50) X 5 server hours = 500 server hours.
  The cost of using virtual servers from Cloud Provider X is (500 X 5 X$10) = $25,000.
  The cost of using virtual servers from Cloud Provider Y is (500 X $20) = $10,600.
  The cloud consumer must therefore choose Cloud Provider Y.
• D. The total usage duration is (20 + 30 + 50) hours = 100 hours.
  The actual usage is (20X3)+ (30X4) + (50X5) hours =430 hours.
  The cost of using virtual servers from Cloud Provider Xis100X5X$10 = $5,000.
  The cost of using virtual servers from Cloud Provider Y is 430 X $20 = $8,600.
  The cloud consumer must therefore choose Cloud Provider X.