Some messaging systems behave as work queues and others as pub/sub system. about vice HOT 7 CLOSED

I made a suggestion in #10 that you actually treat every call to Receive as a subscription. As it is trivial in Go to then take the channel and use it as a work queue by sharing that channel. Where as, if you treated Receive as work-queue like, then every consumer would get the same channel and wouldn't be able to choose to have subscription semantics. Well... without then copying each message and fanning out themselves.

from vice.

At the moment every call to Receive("something") would get the same channel in every implementation.
So if we are using just a single transport on a single node we have already work queue semantics.

But if we create more than one transport or let our program run on more than one node we get sometimes pub/sub and sometimes work queue behaviour.

Receiver.go

package main

import (
	"fmt"

	vn "github.com/matryer/vice/queues/redis"
)

func main() {
	nt := vn.New()
	defer nt.Stop()

	rc := nt.Receive("test123")

	for i := 0; i < 5; i++ {
		v := <-rc
		fmt.Println(string(v))
	}
}

Sender.go

package main

import (
	"fmt"
	"time"

	vn "github.com/matryer/vice/queues/redis"
)

func main() {
	nt := vn.New()
	defer nt.Stop()

	sc := nt.Send("test123")

	for i := 0; i < 5; i++ {
		sc <- []byte(fmt.Sprintf("%d Hallo", i))
		time.Sleep(1 * time.Second)
	}
}

Redis:

NSQ:

from vice.

I suppose vice is intended to be a queue and not pub sub. So queue semantics by default makes sense over subscription.

from vice.

I agree

from vice.

Right, Vice is a queue. It's tough to think of a way to properly test that stuff; so I think we just have to be careful about it in the implementations.

Do we need to tweak anything here?

from vice.

The nats implementation just needs to use QueueSubscribe instead of Subscribe.
I'm sure redis can also be used as a work queue.

from vice.

Solved with #29 and #28

from vice.