C90-06A 全真模擬試験 DEMO

問題2: Cloud Service A is hosted by Virtual Server A, which is hosted by Hypervisor A that resides on
Physical Server A.
Cloud Storage Device A is used to store media library data that is continuously replicated with a
redundant, secondary implementation of Cloud Storage A (not shown). Access to Cloud Service A is
monitored by Pay-Per-Use Monitor A.
Access to Cloud Storage Device A is monitored by Pay-Per-Use Monitor B.
Pay-Per-Use Monitors A and B capture billing-related usage data that is forwarded to a billing
management system that is hosted by Physical Server B.
Cloud Service Consumer A accesses Cloud Service A and the usage data is captured by Pay-Per-Use
Monitor A (1). Cloud Consumer B accesses Cloud Storage Device A via a usage and administration
portal that it uses to upload media data (2). This usage is captured by Pay-Per-Use Monitor B (3).
Pay-Per-Use Monitors A and B store collected usage data in the billing management system (4),
which is later used by the cloud provider to bill for the usage of Cloud Service A and Cloud Storage
Device A.
Each service instance of Cloud Service A requires a virtual server with 2 virtual CPUs and 4 GBs of
RAM at a package price of $2.00 for each initial invocation and an additional $0.50 for each
consecutive 60 seconds of usage. Cloud Service Consumer A accesses Cloud Service A twice in one
day. The two exchanges with Cloud Service A last 60 seconds and 120 seconds. For that one day, the
organization that owns Cloud Service Consumer A is billed $6.50, which it determines is incorrect.
After complaining to the cloud provider, it is discovered that the rapid provisioning system
responsible for provisioning instances of Cloud Service A is not de-provisioning Cloud Service A
when Cloud Service Consumer A indicates it has completed an exchange. Instead, Cloud Service A is
de-provisioned after a 60 second timeout that occurs after Cloud Service Consumer A is completed
with an exchange.
Storage space on Cloud Storage Device A can only be purchased in units of terabytes (TBs), with
each TB costing $1 per day. Cloud Consumer B purchases 5 TBs of storage space on day 1 and stores
5 TBs of data on days 6 and 7. Cloud Consumer B was expecting to be billed $10.00, but is billed $35.
After raising a complaint, Cloud Consumer B is informed by the cloud provider that cloud consumers
are billed based on the allocation of storage space, regardless of how much storage space they
actually use.
Which of the following statements describes a solution that can update the cloud architecture to
avoid these billing-related problems and discrepancies?
A. The Pay-as-You-Go pattern can be applied together with the Usage Monitoring pattern to
establish a monitoring and billing system capable of de-provisioning Cloud Service A instances when
they are no longer required. The Dynamic Data Normalization pattern can be applied to eliminate
any redundant data stored by Cloud Consumer A so that the amount of required storage space is
minimized.
B. The Platform Provisioning pattern can be applied to create an intelligent automation script
capable of immediately de-provisioning cloud service instances. The Redundant Storage pattern can
be applied to introduce a secondary cloud storage device for which storage space can be billed
based on actual usage.
C. The Self-Provisioning pattern can be applied to enable the organization that owns Cloud Service
Consumer B to configure how and to what extent Cloud Service A instances need to be provisioned.
The Resource Management pattern can be applied to establish a storage system that bills cloud
consumers for actual storage space usage only.
D. None of the above.
正解: D