1. Cloud Concepts (20-25%)

1.1 Benefits & Considerations of using cloud services

Reasons to switch to the cloud

• lower operating costs
• run infrastructure more efficiently
• scale as your business needs change
• deliver new features at higher speeds
• limitless pool of raw compute/storage/networking components
• speech recognition + other cognitive services to help make your application stand out
• analytics services that deliver telemetry data from software/devices

Benefits of cloud computing

• High availability: Depending on the service-level agreement (SLA) that you choose, your cloud-based apps can provide a continuous user experience with no apparent downtime, even when things go wrong
• Scalability: Apps in the cloud can scale vertically and horizontally:
  • scale vertically to increase compute capacity by adding RAM or CPUs to a virtual machine
  • scaling horizontally increases compute capacity by adding instances of resources, such as adding VMs to the configuration
• Elasticity: You can configure cloud-based apps to take advantage of autoscaling, so your apps always have the resources they need
• Agility: Deploy and configure cloud-based resources quickly as your app requirements change
• Geo-distribution: You can deploy apps and data to regional datacenters around the globe, thereby ensuring that your customers always have the best performance in their region
• Disaster recovery: By taking advantage of cloud-based backup services, data replication, and geo-distribution, you can deploy your apps with the confidence that comes from knowing that your data is safe in the event of disaster

Capital Expenditure (CapEx) vs. Operational Expenditure (OpEx)

• Capital Expenditure (CapEx): is the up-front spending of money on physical infrastructure, and then deducting that up-front expense over time. The up-front cost from CapEx has a value that reduces over time
• Operational Expenditure (OpEx) is spending money on services or products now, and being billed for them now. You can deduct this expense in the same year you spend it
  • no up-front cost, as you pay for a service or product as you use it

Consumption-based model

• no upfront costs
• no need to purchase and manage costly infrastructure that users might not use to its fullest
• ability to pay for additional resources when they are needed
• ability to stop paying for resources that are no longer needed

1.2 Categories of cloud services

Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS), Software-as-a-Service (SaaS)

Exam: identify cloud service type based on a specific use case

Shared responsibility model

Serverless computing

• Serverless computing: enables developers to build applications faster by eliminating the need for them to manage infrastructure
  • serverless applications, the cloud service provider automatically provisions, scales, and manages the infrastructure required to run the code
  • serverless architectures are highly scalable and event-driven, only using resources when a specific function or trigger occurs

1.3 Types of cloud computing

Definition: Public, Private, Hybrid cloud

• Public cloud
  • services are offered over the public internet and available to anyone who wants to purchase them
  • cloud resources (servers, storage) are owned and operated by a third-party cloud service provider, and delivered over the internet
• Private cloud
  • private cloud consists of computing resources used exclusively by users from one business or organization
  • private cloud can be physically located at your organization’s on-site (on-premises) datacenter, or it can be hosted by a third-party service provider
• Hybrid cloud
  • hybrid cloud is a computing environment that combines a public cloud and a private cloud by allowing data and applications to be shared between them

Comparison

• Public cloud
  • No capital expenditures to scale up
  • Applications can be quickly provisioned and deprovisioned
  • Organizations pay only for what they use
• Private cloud
  • Hardware must be purchased for start-up and maintenance
  • Organizations have complete control over resources and security
  • Organizations are responsible for hardware maintenance and updates
• Hybrid cloud
  • Provides the most flexibility
  • Organizations determine where to run their applications
  • Organizations control security, compliance, or legal requirements