Graceful Shutdown

Graceful shutdown refers to the process where, upon server termination, the system does not abruptly terminate all active connections. Instead, it first stops accepting new requests while allowing existing requests sufficient time to complete processing before shutting down the service. This approach prevents sudden request interruptions, enhancing both user experience and system reliability.

Salvo provides built-in support for graceful shutdown. By obtaining the server handle through the handle method of Server and then invoking the stop_graceful method, you can achieve this functionality. After calling this method, the server will:

Stop accepting new connection requests
Allow ongoing requests to complete processing
Forcefully close any remaining connections after a specified timeout (if provided)

Here’s a simple example:

use salvo_core::prelude::*;

#[tokio::main]
async fn main() {
    let acceptor = TcpListener::new("127.0.0.1:5800").bind().await;
    let server = Server::new(acceptor);
    let handle = server.handle();

    // Gracefully shut down the server
    tokio::spawn(async move {
        tokio::time::sleep(std::time::Duration::from_secs(60)).await;
        handle.stop_graceful(None);
    });
    server.serve(Router::new()).await;
}

In the example above:

server.handle() retrieves the server handle, which can be used to control the server's lifecycle.
handle.stop_graceful(None) initiates the graceful shutdown process. Passing None means no timeout is set, allowing the server to wait indefinitely for all requests to complete.
To enforce a timeout, pass Some(Duration), after which any remaining connections will be forcefully closed.

This approach is particularly useful for applications deployed in containerized or cloud environments, as well as for scenarios requiring hot updates while ensuring uninterrupted request handling.

#Graceful Shutdown

Graceful Shutdown