CompTIA Cloud+ Study Guide. Ben PiperЧитать онлайн книгу.
and expertise required to pull off an IaaS deployment. In these models, the cloud provider handles the compute, storage, and network infrastructure.
Cloud delivery models are important to understand for the exam. You looked at the various types of models, including private, public, community, and hybrid clouds, and what the general use cases and differences are for each type of delivery model.
You also learned about the fundamental characteristics of cloud computing. The cloud offers on-demand, self-service provisioning of elastic resources that you pay for on a metered basis. The chapter discussed resource pooling and virtualization of resources such as storage, CPU, memory, storage, and networking.
The chapter also covered how to prepare to migrate your operations to the cloud and how it's important to test systems in the cloud—including sizing, performance, availability, connectivity, data integrity, and others—and that you document the results.
As you read the rest of the book, keep these fundamental concepts in mind, because they provide a structure that you'll build on as you progress on your journey to become Cloud+ certified.
Exam Essentials
Know that cloud computing is similar in operation to a utility. Cloud computing follows the utilities model where a provider will sell computing resources using an as-needed or as-consumed model. This allows a company or individual to pay for only what they use.
Know what cloud computing is. Cloud computing is a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources (for example, networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction. This cloud model is composed of five essential characteristics, three service models, and four deployment models.
Understand the different cloud service models and how to differentiate between them. Cloud service models are characterized by the phrase as a service and are accessed by many types of devices, including web browsers, thin clients, and mobile devices. There are three primary service types. Software as a Service, Infrastructure as a Service, and Platform as a Service are the core service offerings. Many cloud service providers offer more descriptive terms in their marketing and sales offerings, including Communications as a Service, Anything as a Service, and Desktop as a Service. However, all of these newer terms fit into the SaaS, IaaS, or PaaS service model. Study the service models and know the differences among IaaS, PaaS, and SaaS as well as the other service models.
Know the primary cloud delivery models. The four primary cloud delivery models are public, private, community, and hybrid clouds. Know what each one is and its function. It is critical that you understand the way cloud services are delivered in the market today and what they offer.
Be able to identify and explain cloud components. Common cloud components include applications, automation, compute, networking, security, and storage.
Know the cloud shared resource pooling model and how it is used. Resource pooling is when the cloud service provider abstracts its physical compute, storage, and networking resources into a group, or pool. The resources from these pools are dynamically allocated to customers on-demand. Resource pooling hides the underlying physical hardware from the customers in such a way that different customers share the underlying infrastructure while their cloud resources remain isolated from each other.
Understand cloud performance components. The performance you are able to achieve with your deployment is a combination of the capabilities and architecture of the cloud service provider and how you design and implement your operations. Some metrics that you'll want to consider are bandwidth usage, network latency, storage I/O operations per second (IOPS), and memory utilization.
Be able to explain how autoscaling works. The ability to automatically and dynamically add additional resources such as storage, CPUs, memory, and even servers is referred to as elasticity. Using autoscaling, this can be done “on the fly” as needed or on a scheduled basis. This allows for cloud consumers to scale up automatically as their workload increases and then have the cloud remove the services after the workload subsides. On-demand cloud services allow the cloud customer to access a self-service portal and instantly create additional servers, storage, processing power, or any other services as required. If the computing workload increases, then additional cloud resources can be created and applied as needed. On-demand allows customers to consume cloud services only as needed and scale back when they are no longer required.
Know what regions and availability zones are. Large cloud operations partition operations into geographical regions for fault tolerance and to offer localized performance advantages. A region is not a monolithic data center but rather a geographical area of presence. The actual data centers in each region are availability zones. Each region will usually have two or more availability zones for fault tolerance. The AZs are isolated locations within cloud data center regions that public cloud providers originate and operate. Each availability zone is a physically separate data center with its own redundant power and network connections.
Written Lab
Fill in the blanks for the questions provided in the written lab. You can find the answers to the written labs in Appendix B.
1 With the ___________________ as a Service model, the cloud provider owns and manages all levels of the computing environment.
2 With the ___________________ as a Service model, the cloud provider owns and manages the computing hardware but not the operating systems or the applications.
3 With the ___________________ as a Service model, the cloud provider owns and manages the hardware and operating system but not the application software.
4 ___________________ refers to the ability to access the cloud resources from anywhere in the network from a variety of devices such as laptops, tables, smartphones, and thin or thick clients.
5 ___________________ is the ability to take physical data center resources such as RAM, CPU, storage, and networking and create a software representation of those resources that enables large-scale cloud offerings.
6 Private, low-latency network interconnectivity between your corporate data center and your cloud operations is accomplished using ___________________.
7 ___________________ is the transfer and synchronization of data between computing or storage resources.
8 ___________________ addresses the issues found when cloud workloads and connections increase to the point where a single server can no longer handle the workload by spreading the workload across multiple cloud computing resources.
9 Common remote access protocols used to manage servers in the cloud include ___________________ and ___________________.
10 Establishing ___________________ helps you determine how to size your cloud resources.
Review Questions
The following questions are designed to test your understanding of this chapter's material. You can find the answers in Appendix A. For more information on how to obtain additional questions, please see this book's Introduction.
1 What cloud model gives you complete control of the operating system?IaaSPaaSSaaSCaaS
2 A cloud service provider allocates resources into a group. These resources are then dynamically allocated and reallocated as the demand requires. What is this referred to as?On-demand virtualizationDynamic scalingResource poolingElasticity
3 What are three examples of IaaS elements you can provision in the cloud? (Choose three.)CPUOS ACLsMemoryStorageScalabilitySSH
4 Which of the following is not a valid pooled resource?MemoryStorageSecurityNetworkingCPU
5 What