CloudFlare 522 and HAproxy

Help!
1

Hello,

We use schema:

CloudFlare → HAProxy v.2.4.8 → Nginx-> Tomcat → Application

Sometimes we see error 522 with our clients. Connection cannot be established. From the CF logs it is clear that the connection breaks for 15 seconds https://support.cloudflare.com/hc/en-us/articles/115003011431-Troubleshooting-Cloudflare-5XX-errors#522error

  1. Before a connection is established, the origin web server does not return a SYN+ACK to Cloudflare within 15 seconds of CloudFlare sending a SYN.

What logging for haproxy can be enabled to determine the cause. Is it internet packet loss or something else?

Thanks

2

Why do you have an nginx server in the mix? I’d move that out the way and try again. I have an Apache Guacamole setup like this where the traffic flows like:

Cloudflare → HAProxy → Tomcat → Application

It works perfectly.

3

It was built before me. I don’t have an answer to that question. But your experience is interesting. We have this problem mainly from India. I suppose that sometimes for some reason the handshake becomes very slow.