AZ-900 Episode 1 | Cloud Computing and Vocabulary | Microsoft Azure Fundamentals Full Course

What is Cloud Computing?

Introduction to Cloud Computing

• The episode introduces cloud computing, focusing on essential vocabulary and its benefits.

• Key terms include high availability, scalability, elasticity, agility, fault tolerance, and disaster recovery.

Understanding Cloud Services

• Cloud computing delivers various services such as storage for structured and unstructured data.

• Users can choose from numerous technologies available in the market to utilize within a cloud environment.

Components of Cloud Computing

• Once data is stored in the cloud, users require computational resources like virtual machines or web containers.

• The cloud facilitates application creation across various domains including web applications and AI.

Key Characteristics of Cloud Computing

Scalability

• Scalability refers to the ability to adjust resources based on demand; it can be vertical (increasing resource size) or horizontal (adding more resources).

• Scaling up increases power (CPU/memory), while scaling down decreases it. Scaling out adds resources, whereas scaling in reduces them.

Elasticity

• Elasticity allows systems to dynamically allocate and deallocate resources based on user workload changes throughout the day.

• Automatic scaling is a key feature of elasticity that enables systems to respond without manual intervention.

Agility

• Agility in cloud computing means quickly provisioning resources compared to traditional on-premises environments which may take days or weeks.

• In contrast, cloud resource requests are typically fulfilled within seconds or minutes.

Reliability Features in Cloud Computing

Fault Tolerance

• Fault tolerance ensures that services remain operational during component failures by utilizing multiple servers and disk arrays for redundancy.

• Most cloud services have built-in fault tolerance mechanisms that prevent localized failures from affecting overall service performance.

Disaster Recovery

Disaster Recovery and High Availability Explained

Understanding Disaster Recovery

• Disaster recovery involves creating two copies of the same application across different regions to ensure functionality during disasters such as floods, earthquakes, or power grid failures.

• Replication between these copies is essential; it allows users to be redirected automatically to a functioning version of the application if one fails.

• The primary goal of disaster recovery is to maintain system operations after significant disruptions that could affect entire regions or services.

Defining High Availability

• High availability measures the uptime of a system, comparing how often it is accessible versus how often it experiences downtime due to planned maintenance or unexpected failures.

• A calculation for availability can be made based on agreed metrics with clients; for instance, 99% availability translates to approximately three days of downtime per year.

• Companies typically aim for at least "four nines" (99.99% availability), which equates to about 52 minutes of downtime annually, necessitating specific tools and designs for achievement.

Key Considerations in System Design

• The criticality of a system determines whether high availability should be prioritized; many services inherently offer high availability by default.