How Microsoft outage had global impact

Why in News

A Microsoft cloud-service outage on November 12–13 disrupted email and calendar services across countries, including email services used by Indian airlines.

Prelims Pointers

• Cloud computing provides computing resources over a network on demand, rather than requiring users to own all the underlying equipment.
• The three main cloud-service models are:
  1. Software as a Service (SaaS) provides ready-to-use applications, such as webmail.
  2. Platform as a Service (PaaS) provides an environment for developing and deploying applications.
  3. Infrastructure as a Service (IaaS) provides resources such as virtual machines, storage and networks.
• Exchange Online is Microsoft’s cloud-based email and calendar service. Applications such as Outlook access these services.
• In IaaS, the customer can control the operating system and installed applications, while the provider manages the underlying physical infrastructure.

Prelims Traps

• “SaaS is restricted to desktop computers.” This is incorrect. SaaS applications can also be accessed through mobile devices. (UPSC Prelims 2022)
• “Web-based email services are not examples of SaaS.” This is incorrect. Outlook webmail, Hotmail and Yahoo Mail are examples. (UPSC Prelims 2022)