[Feature]: Zero-downtime in-place update for services

[peterschmidt85]

Problem

Currently, when re-deploying a service (e.g., a newer version), dstack stops the existing run before submitting the new one. This causes a disruption, which is unacceptable for any production-grade service.

Solution

1. Introduce a revision number for service replicas.
2. During an in-place update, ensure that older replicas are only stopped once the newer replicas are successfully running.

Workaround

No response

Would you like to help us implement this feature by sending a PR?

Yes