Chrome SPDY connection error

Hi all,

I’m experiencing an issue with HAProxy 1.8.14 with TLS 1.1, TLS 1.2 and TLS1.3 and alpn h2 enabled configuration. Sometimes endpoint Chrome browsers throws ‘net::ERR_SPDY_PROTOCOL_ERROR’ exception while sending POST to our web backends via HTTPS. If alpn and h2 are disabled, the error disappear.

Haproxy error logs shows termination code ‘CD’ meaning that client closed the connection. But Chrome shows the exact opposite:
–> description = “Server reset stream.”
–> net_error = “ERR_SPDY_PROTOCOL_ERROR”

Network sniffer logs on client side shows that the client sent a POST request to the haproxy, but didn’t get a response.

Any idea what can cause those errors, and how can I debug them on haproxy side?


Which Chrome release is this exactly?

The latest one on Mac.

We tried to work directly on the backends but the issue is not reproducing. It seems like a problem with the backends.