Anycast behavior?

[xorander00]

First off, thanks for the great project, I love it! :)

Probably a dumb question, but I I didn't see it in the docs (or I just plain missed it). Is there an easy way to set up anycast behavior? I have an application where I have multiple nChan instances with shared Redis storage. Clients will publish messages to a channel that will have a pool of workers listening. A single worker should pick up the request & process it, so I don't want multiple workers listening.

I can think of two options for this:

• See if nChan can be configured to remove a message once a subscribe has acknowledged it. I guess the subscriber could remove the message itself maybe, but I'd have to make sure there's no contention for it between multiple workers. Maybe check that the message exists before removing it?
• Write a single worker that manages the worker pool itself. This worker would subscribe to the channel, pick up messages, and assign & dispatch it to a worker in the pool.

This is for front-end clients to use for real-time search. I'd like to it be as low-latency as possible, so it'll be done via WebSockets and the worker pool will be warmed up & ready to go. My back-end system uses RabbitMQ for this and it works fine, so I just need to solve it for the front-end. Thoughts? :)

[slact]

Right now Nchan only supports the broadcasting pattern. Anycast requires additional semantics and configuration (distance measurements/load balancing) that I haven't yet thought through. There is, however, some overlap here with anycasting a message to exactly n subscribers.

So this is a feature I'm open to implementing. How badly do you want it, and is it something you'd like to sponsor?

[xorander00]

It's not a huge deal right now as this is for a longer-term project and isn't planned for deployment anytime soon. I'm interested in taking a crack at it myself, but it won't be for at least another couple of months as my schedule is busy.

What does sponsoring entail? If it's something I can manage then I can put it on my agenda for Q1 of next year.

[slact]

Got it. Shoot me an email at leo@nchan.io and I'll give you some more info. You can also check out https://nchan.io/support .