HAProxy community

Intermittent "SD" termination state

Hello HAProxy Experts!

we are intermittently finding requests with a termination state of “SD” in our HAProxy logs. Most requests have zero bytes responded but some show some random number of bytes before it reports the “SD” status. We are seeing this status at a rate of about 1 every 1000 requests.
We can attribute some of them to backend servers being ungracefully restarted in our Kubernetes cluster. However about 10% of those cannot be related to any event. We have already done extensive research in our network but everything looks ok.

We are running HAProxy 1.9.9 on the “client” side and HAProxy 1.9.10 on the “server” side. Both environments are on CentOS 7.

Some further search turned up this old HAProxy bug https://www.mail-archive.com/haproxy@formilux.org/msg26282.html and we are wondering whether this could be a regression that crept back into version 1.9 from 1.7.

Thank you,
-Ulrich