Resilient connections

[joelittlejohn]

Any client of the Slack RTM API will need to ensure that they reinstate their websocket when the connection drops. Unfortunately (I think) this currently means re-wiring your application to a new dispatcher etc whenever there is a connection drop. It would be great if this library supported a 'resilient' mode that would recreate a dropped internal connection and wire the new connection to the same channels.

What do you think?

I've been pondering whether this feature request should target slack-rtm or gniazdo. I think it makes sense that gnaizdo manages individual connections and higher-level libraries like this one manage those.

[casidiablo]

I hadn't seen this one; apologies.

I think it makes sense to implement this at the slack-rtm level. I will try to get back to this as soon as possible, but it will be a while before I can dedicate my full attention to it.

Thanks for your input!

[devth]

I have an :on-close handler that looks like this:

(defn on-close [conn config status]
  (log/info "close" (:name config) status)
  (when (not= (:reason status) "Shutdown")
    (try-try-again
      {:decay 1.1 :sleep 5000 :tries 500}
      (fn []
        (log/info "attempt no. " rb/*try* " to rereconnect to slack")
        (when rb/*error* (log/info "previous attempt errored:" rb/*error*))
        (when rb/*last-try* (log/warn "this is the last attempt"))
        (restart conn config)))))

Relies on https://github.com/joegallo/robert-bruce to retry with backoff. Before I was having to restart my bot every day or two. Now it runs indefinitely (months+ from what I've observed).

Full source at https://github.com/devth/yetibot.core/blob/master/src/yetibot/core/adapters/slack.clj

[holyjak]

@casidiablo What do you think about @devth's approach?

I am just creating a bot with slack-rtm and would like to have this in so perhaps I can just integrate his approach and send you a PR. But the question is whether you want to add robert-bruce as a dependency or whether to implement something simpler manually.

[casidiablo]

I'd rather not introduce another dependency. This particular problem does not seem to complicated anyway.

Contributions are always welcome, thank you so much!