This setting is similar to the SO_LINGER socket option but does not only include the OS-level socket but also covers the Akka IO / Akka Streams network stack. The linger timeout is the time period the HTTP server implementation will keep a connection open after all data has been delivered to the network layer. It can be configured using the -timeout setting. The bind timeout is the time period within which the TCP binding process must be completed (using any of the Http().bind* methods). The request timeout can be configured at run-time for a given route using the any of the TimeoutDirectives. "to produce a timely response to your request.\r\nPlease try again in a short while!")Ī default request timeout is applied globally to all routes and can be configured using the -timeout setting (which defaults to 20 seconds). The default HttpResponse HttpResponse that is written when a request timeout is exceeded looks like this: copy source HttpResponse(StatusCodes.ServiceUnavailable, entity = "The server was not able " + If that deadline is not met the server will automatically inject a Service Unavailable HTTP response and close the connection to prevent it from leaking and staying around indefinitely (for example if by programming error a Future would never complete, never sending the real response otherwise). Request timeouts are a mechanism that limits the maximum time it may take to produce an HttpResponse HttpResponse from a route.
The setting works the same way for server and client connections and it is configurable independently using the following keys: -timeoutĪ.idle-timeout This setting should be used as a last-resort safeguard to prevent unused or stuck connections from consuming resources for an indefinite time. If no data is sent or received on a connection for over idle-timeout time, the connection will be automatically closed. The idle-timeout is a setting which sets the maximum inactivity time of a given connection. Common timeouts Connection-level idle timeout Some of these are simply configuration options (which may be overridden in code) while others are left to the streaming APIs and are easily implementable as patterns in user-code directly. You set them by explicitly using a Server: srv := &http.Akka HTTP comes with a variety of built-in timeout mechanisms to protect your servers from malicious attacks or programming mistakes. There are two timeouts exposed in http.Server: ReadTimeout and WriteTimeout. Otherwise very slow or disappearing clients might leak file descriptors and eventually result in something along the lines of: http: Accept error: accept tcp :80: accept4: too many open files retrying in 5ms It's critical for an HTTP server exposed to the Internet to enforce timeouts on client connections. The "So you want to expose Go on the Internet" post has more information on server timeouts, in particular about HTTP/2 and Go 1.7 bugs. However, keep in mind that all timeouts are implemented in terms of Deadlines, so they do NOT reset every time data is sent or received. You probably don't want to call SetDeadline yourself, and let net/http call it for you instead, using its higher level timeouts. So to build a timeout with SetDeadline you'll have to call it before every Read/ Write operation. Once set they stay in force forever (or until the next call to SetDeadline), no matter if and how the connection is used in the meantime.
SetDeadlineįirst, you need to know about the network primitive that Go exposes to implement timeouts: Deadlines.Įxposed by net.Conn with the SetDeadline(time.Time) methods, Deadlines are an absolute time which when reached makes all I/O operations fail with a timeout error.ĭeadlines are not timeouts. In this post I’ll take apart the various stages you might need to apply a timeout to, and look at the different ways to do it, on both the Server and the Client side. Indeed, the defaults are often not what you want. Think about a streaming endpoint versus a JSON API versus a Comet endpoint. HTTP is a complex multi-stage protocol, so there's no one-size fits all solution to timeouts. When writing an HTTP server or client in Go, timeouts are amongst the easiest and most subtle things to get wrong: there’s many to choose from, and a mistake can have no consequences for a long time, until the network glitches and the process hangs.
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