postgres listen/notifiy with golang and `go-pg`

pg-notify-parallel.go

package main

import (
	"log"
	"time"

	"github.com/go-pg/pg"
)

const maxWorkers = 5

var (
	limiter = make(chan int, maxWorkers)
)

func main() {

	db := pg.Connect(&pg.Options{
		User:            "seba",
		ApplicationName: "test_notify",
	})

	ln := db.Listen("mychan")
	defer ln.Close()

	ch := ln.Channel()
	for notifyOutput := range ch {
		limiter <- 1
		go processMessage(notifyOutput.Payload)
	}
}

func processMessage(message string) {
	log.Printf("[ %d / %d ] added to queue: %s\n", cap(limiter), maxWorkers, message)
	time.Sleep(1 * time.Second)
	<-limiter
}

pg-notify.go

package main

import (
	"log"

	"github.com/go-pg/pg"
)

func main() {

	db := pg.Connect(&pg.Options{
		User:            "seba",
		ApplicationName: "test_notify",
	})

	ln := db.Listen("mychan")
	defer ln.Close()

	ch := ln.Channel()
	for val := range ch {
		processMessage(val.Payload)
	}
}

func processMessage(message string) {
	log.Println("received message:", message)
}