Azure deployment slot swaps facilitate seamless application updates with minimal to no downtime by exchanging the content and configuration between two slots. This process involves several key steps:
Preparation of the Source Slot:
Settings from the target slot (e.g., production) are applied to all instances of the source slot (e.g., staging). These settings include slot-specific app settings, connection strings, continuous deployment settings, and authentication configurations.
The source slot instances restart with these new settings and are "warmed up" to ensure they are ready to handle requests. This warming-up period is crucial for avoiding cold starts and ensuring a smooth transition.