actix-website/content/docs/server.md

title	menu	weight
Server	docs_basics	150

The HTTP Server

The HttpServer type is responsible for serving http requests.

HttpServer accepts an application factory as a parameter, and the application factory must have Send + Sync boundaries. More about that in the multi-threading section.

To bind to a specific socket address, bind() must be used, and it may be called multiple times. To bind ssl socket bind_ssl() or bind_tls() should be used. To start the http server, one of the start methods.

• use start() for a server

HttpServer is an actix actor. It must be initialized within a properly configured actix system:

{{< include-example example="server" section="main" >}}

It is possible to start a server in a separate thread with the run() method. In that case the server spawns a new thread and creates a new actix system in it. To stop this server, send a StopServer message.

HttpServer is implemented as an actix actor. It is possible to communicate with the server via a messaging system. Start method, e.g. start(), returns the address of the started http server. It accepts several messages:

• PauseServer - Pause accepting incoming connections
• ResumeServer - Resume accepting incoming connections
• StopServer - Stop incoming connection processing, stop all workers and exit

{{< include-example example="server" file="signals.rs" section="signals" >}}

Multi-threading

HttpServer automatically starts an number of http workers, by default this number is equal to number of logical CPUs in the system. This number can be overridden with the HttpServer::workers() method.

{{< include-example example="server" file="workers.rs" section="workers" >}}

The server creates a 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 factories must be Send + Sync.

SSL

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

[dependencies]
actix-web = { version = "{{< actix-version "actix-web" >}}", features = ["alpn"] }

{{< include-example example="server" file="ssl.rs" section="ssl" >}}

Note

: the HTTP/2.0 protocol requires tls alpn. At the moment, only openssl has alpn support. For a full example, check out examples/tls.

To create the key.pem and cert.pem use the command. Fill in your own subject

$ openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem \
  -days 365 -sha256 -subj "/C=CN/ST=Fujian/L=Xiamen/O=TVlinux/OU=Org/CN=muro.lxd"

To remove the password, then copy nopass.pem to key.pem

$ openssl rsa -in key.pem -out nopass.pem

Keep-Alive

Actix can wait for requests on a keep-alive connection.

keep alive connection behavior is defined by server settings.

• 75, Some(75), KeepAlive::Timeout(75) - enable 75 second keep alive timer.
• None or KeepAlive::Disabled - disable keep alive.
• KeepAlive::Tcp(75) - use SO_KEEPALIVE socket option.

{{< include-example example="server" file="ka.rs" section="ka" >}}

If the first option is selected, then keep alive state is calculated based on the response's connection-type. By default HttpResponse::connection_type is not defined. In that case keep alive is defined by the 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 can be change with HttpResponseBuilder::connection_type() method.

{{< include-example example="server" file="ka_tp.rs" section="example" >}}

Graceful shutdown

HttpServer supports graceful shutdown. After receiving a stop signal, workers have a specific amount of time to finish serving requests. Any workers still alive after the timeout are force-dropped. By default the shutdown timeout is set to 30 seconds. You can change this parameter with the HttpServer::shutdown_timeout() method.

You can send a stop message to the server with the server address and specify if you want graceful shutdown or not. The start() methods returns address of the server.

HttpServer handles several OS signals. CTRL-C is available on all OSs, other signals are available on unix systems.

• SIGINT - Force shutdown workers
• SIGTERM - Graceful shutdown workers
• SIGQUIT - Force shutdown workers

It is possible to disable signal handling with HttpServer::disable_signals() method.