Max Subscriptions in Gp

max-subs.go

package main

import (
	"crypto/rand"
	"encoding/hex"
	"fmt"
	"io"
	"log"
	"runtime"

	"github.com/nats-io/nats"
)

func newSubject() string {
	u := make([]byte, 13)
	io.ReadFull(rand.Reader, u)
	return fmt.Sprintf("DEVICE.%s.OUTPUT", hex.EncodeToString(u))
}

func main() {
	opts := nats.DefaultOptions
	opts.SubChanLen = 1
	opts.Url = "nats://demo.nats.io:4222"
	nc, err := opts.Connect()
	if err != nil {
		log.Fatalf("Can't connect: %v\n", err)
	}
	numSubs := 1000000
	log.Printf("Starting %d subscriptions\n", numSubs)
	for i := 0; i < numSubs; i++ {
		nc.SubscribeSync(newSubject())
	}
	nc.Flush()
	log.Printf("Done")
	runtime.Goexit()
}