What approaches should be used for deploying applications with long restart times?

The following approaches are used for deploying applications with long restart times:

• Blue-Green Deployment: two environments (blue and green) are maintained. The new version is deployed in the inactive environment, after which traffic is switched instantly. This minimizes downtime.

• Rolling Update: the update occurs gradually, one application instance at a time, so that part of the system remains available.

• Canary Deployment: the new version is launched on a small part of the infrastructure to test stability before full deployment.

• Readiness Probes and Health Checks: allow the system to understand when the application is ready to receive traffic, preventing requests during restart.

• Use of queues and buffers: to avoid losing requests during restart, intermediate buffers or message queues can be used.

These methods help ensure high availability and minimize the impact of long restarts on users.