Relay graceful shutdown implementation

[sameh-farouk]

The RMB relay does not have a complete graceful shutdown implementation. Here are the key observations:

1. The main relay server loop in src/relay/mod.rs runs in an infinite loop without any shutdown handling.
2. The federation worker also runs in an infinite loop in src/relay/federation/mod.rs without shutdown handling.
3. The chain event listener in src/events/mod.rs also lacks shutdown handling.

I recommend implementing proper graceful shutdown handling to ensure reliable operation, maintain data integrity, and prevent resource leaks.

To implement proper graceful shutdown, the relay should:

1. Handle OS signals (SIGTERM, SIGINT)
2. Propagate shutdown signals to all components
3. Allow in-flight messages to complete
4. Close active connections cleanly
5. Flush any remaining data to Redis
6. Clean up any resources

[Nabil-Salah]

5-12-2024

investigate how to do graceful shutdown in rust

[Nabil-Salah]

11-12-2024

implemented graceful shutdown on files specified on the issue and opened a draft pr

[Nabil-Salah]

12-12-2024

reviewed graceful shutdown pr
was in meet with ashraf about tracing a problem in rmb

[Nabil-Salah]

2-1-2025

Start exploring Tokyo tutorial