Presence user momentarily disappears in Phoenix 1.4

[drl123]

I set up a simple chat demo app with Phoenix Presence, pretty much following the Presence Guide. The app works, but occasionally when a user posts a new message, the Presence list loses a user or two and then they come back…often it is the user just posting that goes away and comes back a second or two later.

It does the same on my local in dev mode and on the demo app I set up on Heroku (https://forever-chat.herokuapp.com) running in production mode. Just open two tabs or browsers with different users and post some messages to see what I mean.

Any suggestions or ideas what may be happening? (I assume this is not expected behavior)

[chrismccord]

Do you have the elixir channel and javascript code you can share? Do the logs show a crash when you post a message? There is either a bug on the server or client, since your deployed app shows the client rejoin when sending a message, which would cause the flapping presences you are seeing:

[Log] Joined successfully – Object 
[Log] new_msg received with: {body: bar, name: foo}
[Log] Joined successfully – {} 

[drl123]

Thanks Chris…Stupid typo bit me…had handler for new message returning no_reply instead of noreply. The errors were not showing in the Heroku logs, but were in the local.

Thanks for the help and sorry for the false alarm!