actix-extras/guide/src/qs_3_5.md

Server

Multi-threading

Http server automatically starts number of http workers, by default this number is equal to number of logical cpu in the system. This number could be overridden with HttpServer::threads() method.

# extern crate actix_web;
# extern crate tokio_core;
# use tokio_core::net::TcpStream;
# use std::net::SocketAddr;
use actix_web::*;

fn main() {
    HttpServer::<TcpStream, SocketAddr, _, _>::new(
        || Application::new()
            .resource("/", |r| r.f(|r| httpcodes::HTTPOk)))
        .threads(4); // <- Start 4 threads
}

Server create separate application instance for each created worker. Application state is not shared between threads, to share state Arc could be used. Application state does not need to be Send and Sync but application factory must be Send + Sync.

SSL

There are two tls and alpn features for ssl server. tls feature is for native-tls integration and alpn is for openssl.

[dependencies]
actix-web = { git = "https://github.com/actix/actix-web", features=["alpn"] }

use std::fs::File;
use actix_web::*;

fn main() {
    let mut file = File::open("identity.pfx").unwrap();
    let mut pkcs12 = vec![];
    file.read_to_end(&mut pkcs12).unwrap();
    let pkcs12 = Pkcs12::from_der(&pkcs12).unwrap().parse("12345").unwrap();

    HttpServer::new(
        || Application::new()
            .resource("/index.html", |r| r.f(index)))
        .serve_ssl::<_, ()>("127.0.0.1:8080", pkcs12).unwrap();
}

Note on HTTP/2.0 protocol over tls without prior knowledge, it requires tls alpn. At the moment only openssl has alpn support.

Please check example for concrete example.

Keep-Alive

Actix can wait for requests on a keep-alive connection. Keep alive connection behavior is defined by server settings.

• Some(75) - enable 75 sec keep alive timer according request and response settings.
• Some(0) - disable keep alive.
• None - Use SO_KEEPALIVE socket option.

# extern crate actix_web;
# extern crate tokio_core;
# use tokio_core::net::TcpStream;
# use std::net::SocketAddr;
use actix_web::*;

fn main() {
    HttpServer::<TcpStream, SocketAddr, _, _>::new(||
        Application::new()
            .resource("/", |r| r.f(|r| httpcodes::HTTPOk)))
        .keep_alive(None); // <- Use `SO_KEEPALIVE` socket option.
}

If first option is selected then keep alive state calculated based on response's connection-type. By default HttpResponse::connection_type is not defined in that case keep alive defined by request's http version. Keep alive is off for HTTP/1.0 and is on for HTTP/1.1 and "HTTP/2.0".

Connection type could be change with HttpResponseBuilder::connection_type() method.

# extern crate actix_web;
# use actix_web::httpcodes::*;
use actix_web::*;

fn index(req: HttpRequest) -> HttpResponse {
    HTTPOk.build()
        .connection_type(headers::ConnectionType::Close) // <- Close connection
        .force_close()                                   // <- Alternative method
        .finish().unwrap()
}
# fn main() {}