Cloud Computing is the delivery of computing services over the internet enabling faster innovation, resources and economics of scales. The fundamental components of cloud infrastructure include;
- Compute
- Networking
- Storage.
Cloud deployment models: Cloud deployment models is where the cloud is hosted, it includes;
- Private cloud: This is a deployment model in which all resources are hosted in your data center, organizations create a cloud environment in their data center.
Data center is a building that consists storage systems, servers, routers etc..
- Public cloud: A deployment model that is owned by cloud services or hosting providers examples are Azure owned by Microsoft, AWS owned by amazon, GCP and others.
- Hybrid cloud: A deployment model that involves combination of public and private cloud to allow applications to run in most appropriate locations.
- Community cloud: A cloud model that allows organizations with shared interest to share information.
- Multi-cloud: Uses services from multiple cloud providers. An organization can choose to use different cloud platforms.
CapEx(Capital Expenditure) VS OpEx(Operational Expenditure)
-CapEx is the upfront spending of money on physical infrastructure.
-Costs from CapEx have a value that reduces overtime. Let’s say you buy a server for $5000, in the first year the value of the server maybe worth $4000, in the second year it may drop to $2500. CapEx assets keep depreciating over time.
-OpEx is spending on products and services as needed. PAY-AS-YOU-GO.
-No initial investment and you get billed immediately.
Consumption-Based Model:
This is similar to Operational Expenditure (OpEx) Cloud service providers operate on a consumption-based model which means that users pay for only the resources that they use.
Consumption-based model helps with;
- Better cost prediction
- Prices for individual resources and services are provided
- Billing is based on actual usage.
Benefits of cloud:
- High Availability: This means it is always available with minimum downtime
- Scalability: This means it has the ability to increase or decrease resources. Scalability can either be horizontal (adding resources to your computer e.g. adding more RAM and ROM) or vertical (buying more computers to make up to your workload).
- Predictability: Knowing how much you will be spending i.e. resources, money etc..
- Elasticity: Ability to scale dynamically, being able to adjust based on workload
- Reliability: Ability to continue its function without failure
- Manageability: It is easy to manage cloud resources
Cloud Service Models: the cloud service models are
- Infrastructure as a service (IaaS): It provides an IT infrastructure by renting the servers, storage, network, virtualization and the users manages the operating system, applications, data and middleware
- Platform as a service (PaaS): It provides an environment for building, testing and deploying software applications where the user manages the application and data.
- Software as a service (SaaS): It is a fully managed by the cloud provider. Users connect to use cloud-based apps over the internet. Examples are M365, Calendars etc.
Data Center: A data center is a physical facility used to run cloud services that consists of storage systems, servers, routers etc.
Region: It is a geographical area where we have one or more data centers and its spread over the world. The closer you are to a region the faster you get your resources.
Availability Zone: It physically separates data centers within same region and provides protection against downtime due to data center failure.
Paired Region: Azure pairs each region with another region in same geography and are at least 300 miles distance from each other.
Azure Sovereign Regions (US government services): These are isolated Azure cloud environments designed for US government deployments. It is accessible only to screened authorized personnel.
Azure sovereign Regions (Azure China): It is managed by China on behalf of Microsoft and operated by the 21vianet. All the data stays within China.