Active Upgrade –

Definition:
An active upgrade refers to the process of updating or replacing a sequenced application package (typically used in application virtualization environments) without requiring a server restart or interrupting the service that streams the application to end users.

Key Concepts-

• Sequenced Application Package:
  This is a virtualized version of an application created using tools like Microsoft App-V. The app is packaged in a way that allows it to run in a self-contained environment, separate from the underlying OS.
• Streaming Server:
  This server delivers (or “streams”) the virtualized application package to client machines on demand. It’s crucial in scenarios where applications aren’t installed locally but are needed quickly and efficiently by users.
• Upgrade Process:
  In a traditional upgrade, the server may need to be stopped or rebooted to replace an application package, potentially causing downtime.
  In an active upgrade, the server continues running, and users can still access existing versions of the application while the new version is being introduced.

Benefits of Active Upgrade-

• Zero Downtime:
  Users can continue working without interruption while the upgrade happens in the background.
• Improved IT Efficiency:
  Administrators can manage and roll out updates without coordinating maintenance windows or dealing with service outages.
• Version Flexibility:
  Multiple versions of a package may coexist temporarily, allowing gradual rollouts or phased testing.

Use Cases-

• Enterprises using Microsoft App-V or similar solutions where application virtualization and streaming are critical for managing distributed users.
• Environments requiring high availability and minimal disruption, such as healthcare, finance, or large corporate infrastructures.

How It Works –

1. A new version of the application is sequenced and tested.
2. The updated package is uploaded to the streaming server.
3. The server registers the new version while still serving the old one.
4. New client sessions may get the updated version, while existing ones finish using the old one.
5. After a transition period, the older version is retired.