How to increase the server timeout on the fly

Question

In PHP we have ini_set('max_execution_time', 180) by which we can change the execution time on the fly. Is there anything similar to this in Go?

No, there's not. It wouldn't really make sense in Go, either, since Go isn't single-threaded like PHP. — Jonathan Hall, Nov 06 '19 at 10:19
The only similar timeouts Go offers are the various Timeouts in the [`http.Server`](https://golang.org/pkg/net/http/#Server) struct. And they can only be set on startup (although you could construct a program that would re-start a server when config changes, without restarting the whole process--but probably not worth it) — Jonathan Hall, Nov 06 '19 at 10:21
A more dynamic approach would be to set a context timeout (perhaps in middleware) per connection. That could easily be done without restarting, but would only affect new connections. — Jonathan Hall, Nov 06 '19 at 10:22
The context approach as suggested by @Flimzy is how I go about it. I have a `middleware` per se, which calls `context.WithTimeout` to create a new context. To make it dynamic, you can pick the value from an env variable to avoid restarting — Ayush Gupta, Nov 06 '19 at 11:05
@AyushGupta: You cannot reset an ENV variable without restarting, though. — Jonathan Hall, Nov 06 '19 at 11:08
@Flimzy oh is that? Then maybe another mechanism. Personally I would want(expect, perhaps) to pick the latest env variable value, but I guess caching that makes sense too(I believe it's cached at a shell level). Good to know, thanks — Ayush Gupta, Nov 06 '19 at 11:16
@AyushGupta: See here: https://stackoverflow.com/q/205064/13860 TL;DR; There are hacky ways to change an env variable while the process is running, but there's no standard way to tell the process to re-read the env variables, so in practice, it's impossible. (And I'm sure the Go runtime doesn't support it, so you'd be stuck doing some low-level system calls to re-read the env) — Jonathan Hall, Nov 06 '19 at 11:18

Charana · Answer 1 · 2019-11-06T12:18:35.850

Heres a script that allows you to set a program timeout and dynamically change timeout during execution. https://play.golang.org/p/qRvVMPnp9g2

package main

import (
    "fmt"
    "time"
    "os"
)

var (
    oldDuration time.Duration = 10 * time.Second
    timer *time.Timer = time.NewTimer(oldDuration)
    start time.Time = time.Now()
)

// The init function is called before main
func init(){
    // function asynchronously monitors and terminates script after timeout
    go func(){
        <- timer.C
        fmt.Println("Exit")
        os.Exit(1)
    }()
}

func main() {

    // Do some work
    <-time.After(2 * time.Second)
    fmt.Println("Hello World")

    // Change timeout interval dynamically
    setTimeout(5 * time.Second)

    // Do more work
    <-time.After(5 * time.Second)
    fmt.Println("Shouldn't be reached as script terminates after 5 seconds of which 2 seconds have been used earlier")
}

func setTimeout(newDuration time.Duration){

     // Stop timer - prevent program terminating in setTimeout function
     timer.Stop()

     // Compute remaining time
     var timePassed time.Duration = time.Since(start)
     var timeToTermination time.Duration = newDuration - timePassed

     // Restart timer - continuing from however many second 
     // have elapsed since the program started
     oldDuration = newDuration
     timer.Reset(timeToTermination)
}

How to increase the server timeout on the fly

1 Answers1