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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 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 (10 + 20 + 70) x 12 hours = 1.200 hours.
  The actual usage is (10X6) + (20X4) + (70X2) hours = 280 server hours.
  The cost of using virtual servers from Cloud Provider Xis12X100X5X$10 = $60,000.
  The cost of using virtual servers from Cloud Provider Y is 280 X $20 = $5,600.
  The cloud consumer must therefore choose Cloud Provider Y.
• B. The total usage duration is (10 + 20 + 70) hours = 100 hours.
  The actual usage is (10 X 6) + (20 X 4) + (70 X 2) hours = 280 hours.
  The cost of using virtual servers from Cloud Provider X is 100X6X$10 = $6,000.
  The cost of using virtual servers from Cloud Provider Y is 280 X $20 = $5,600.
  The cloud consumer must therefore choose Cloud Provider Y.
• C. The total usage duration is (10 + 20 + 70) hours = 100 hours.
  The actual usage is ((10 X 6) + (20 X 4) + (70 X 2)) x ((2 + 4 + 6) / 3) hours = 1,120 hours
  The cost of using virtual servers from Cloud Provider X is 6 X 100 X $10 = $6,000.
  The cost of using virtual servers from Cloud Provider Y is 1,120 X $20 = $22,400.
  The cloud consumer must therefore choose Cloud Provider Y.
• D. The total usage duration is (10 + 20 + 70) hours = 100 hours.
  The actual usage is ((10 X 6) + (20 X 4) + (70 X 2)) x ((2 + 4 + 6) / 3) hours = 1,120 hours
  The cost of using virtual servers from Cloud Provider Xis10QX6X$10 = $6,000.
  The cost of using virtual servers from Cloud Provider Y is 1,120 X $20 = $22,400.
  The cloud consumer must therefore choose Cloud Provider X.

Cloud X (owned by Cloud Provider X) provides Physical Server A which hosts Virtual Servers A and B. Virtual Server B hosts Ready-Made Environments A and B. Cloud Service Consumer A uses Virtual Server A as part of an IaaS leasing agreement in which Cloud Consumer A is charged a fixed monthly fee for unlimited access. Cloud Service Consumers B and C use Ready-Made Environments A and B respectively as part of a PaaS leasing agreement based on per-minute usage fees. In both cases, access is monitored via Pay-For-Use Monitor A, which keeps track of log-in and log-out times in order to calculate the usage charges that are billed to Cloud Consumers B and C.
Virtual Server A begins generating a series of exceptions. Soon thereafter, Virtual Server B becomes destabilized, resulting in further exceptions being raised in Ready-Made Environments A and B. Cloud Service Consumers B and C receive a series of error messages until both of their connections are dropped Finally, Physical Server A shuts down completely. A subsequent investigation reveals that Virtual Server A was the victim of a security attack performed by a malicious cloud service consumer, the attacker generated increased loads of external communication requests on Virtual Server A and the underlying network, causing Physical Server A (along with Virtual Server B) to eventually shut down.

Which of the following statements accurately identifies the type of security threat that corresponds to the described attack - and -provides a solution that can directly mitigate this type of security threat within Cloud X?

• A. Virtual Server A was subjected to an insufficient authorization attack that can be mitigated by implementing the single sign-on mechanism.
• B. Virtual Server A was subjected to a denial of service attack that can be mitigated by implementing the hardened virtual server image and identity and access management mechanisms.
• C. Virtual Server A was subjected to an insufficient authorization attack that can be mitigated by implementing the digital signature and hardened virtual server image mechanisms.
• D. Virtual Server A was subjected to a denial of service attack that can be mitigated by implementing the encryption and digital signature mechanisms.

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. 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.
• D. 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.