Your program does not wait for all the goroutines to complete. If I add a sync.WaitGroup to make sure that all goroutines complete, I see all the expected output lines.

nice! Seems to solve the issue for now for the sample program. Thanks! My issue here was apparently, that the program was clased before the goroutines finished.

However this will not solve the issue with my normal program - as the programm runs infinitely, but my logs dissappear too. Is there a smoother way to access the standard output than just using fmt.Println() or println()? Or a way of debugging this behaviour?

btw: For anyone who is interested in the sync solution:

package main

import (
	"fmt"
	"sync"
)

func main() {
	var wg sync.WaitGroup
	x := 0
	for x < 1000 {
		//println(x)
		wg.Add(1)
		go myPrintFunc(x, &wg)
		x++
	}
	fmt.Println(x)
	wg.Wait()
}

func myPrintFunc(i int, wg *sync.WaitGroup) {
	fmt.Println(i)
	wg.Done()
}

Where are your logs going? If they are going to a file that is not opened in append mode, then I think that multiple concurrent writes can overlap. This should not happen if they are going to the ordinary standard output/standard error, nor if they are going to a file opened in append mode.

achtually they are indeed going to either println() or fmt.Println() as I've configured my docker host to redirect the logfiles to a central search server.

But I am seeing the issues while performing jmeter load-tests even without the docker-environment (round about 700 requests per second) - so only println to the standard output... :D that is why I thought one output would oust the other