AZ-900_MS-Azure-Fundamentals 我的复习整理

我在github中的网页：https://github.com/yasenstar/cloud_computing/tree/master/ms_azure

AZ-900_MS-Azure-Fundamentals

1. Cloud Concepts

One of the primary benefits for moving to the cloud is removing some of the IT burden from your own company.

1.1 Benefits and Considerations of Using Cloud Services

• High Availability

  • Network Outage

  • Application Failure

    • Software Bug
    • Application Design

  • System, such as a VM, Outage

  • Power Outage

  • Problem with a Reliant System such as External Databases

• Scalability, Elasticity and Agility

  • Scaling is the process of adding additional resources or additional power for your application

    In addition to Scaling Out and Scaling Up, you can also Scaling In and Scaling Down to decrease resource usage.

    • Horizontal Scaling (Scaling Out): add additional VMs for application, each VM you add is identical to other VMs servicing your application
    • Vertical Scaling (Scaling Up): move to a new VM with additional resources.

  • The conecpt of automatically scaling is referred to as Elasticity

    • In Azure, you can scale automatically by configuring Auto-Scale
    • One of major benefits of the cloud is that it allows you to quickly scale.

  • The speed and flexibility of scaling in the cloud is call ed Cloud Agility

• Fault Tolerance and Disaster Recovery

  • Fault Tolerance v.s. Scaling

    • Scaling allows you to react to additional load or resource needs, but it’s always assumed that all of the VMs you are using are healthy.
    • Fault Tolerance happens without any interaction from you, and it’s designed to automatically move you from an unhealthy system onto a healthy system in the event that things go wrong.s

  • Fault Tolerance is designed to deal with failure at a small scale; moveing you, e.g. from an unhealthy VM to a healthy VM.

  • Disaster Recovery not only means having reliable backups of important data, but it also means that the cloud infrastructure can replicate your application’s resources in an unaffected region so that your data is safe and your application availaibility isn’t impacted.

• Principles of Economies of Scale

  • Differences between Capital Expenditures (CaPEX) and Operations Expenditures (OPEX)

    • Capital E