MessageBus short polling is not working

[DeanMarkTaylor (Dean Taylor)]

Not that I have much experience in this specific problem, but some thoughts…

Depending on your AWS ELB setup you might be falling into the “Full site CDN acceleration” category.
This depends on settings etc at many levels before you get to Discourse, ALB, NLB or Classic Load Balancer might make a difference.

Full site CDN acceleration for Discourse

Fastly , CloudFlare and a few other CDNs offer a mode where they accelerate dynamic content. In a nutshell you point your domain IP address at the CDN and the CDN will intelligently decide how to deal with the request. Static content can be easily served from cache Dynamic content can be routed to the site. This provides some advantages over only shipping static assets which is covered in the CDN howto. You can elect for “shielding” that protects your site from traffic spikes. Dynamic cont…

Specifically point you at rule number one:

@sam

If you enable full site acceleration with a CDN it is critical you follow 3 rules

1. The “message bus” must be served from the origin.
2. You need to set up X-Forwarded-For trust. For Cloudflare, add cloudflare.template.yml to your app.yml file.
3. Be extra careful with techniques that apply optimisation to the site, stuff like Rocket Loader can stop Discourse from working. Discourse is already heavily optimised, this is not needed.