HAProxy community

Session state SDNN + http status code 200 when upgrading to 1.7



We are seeing some weird behaviour after upgrading to HaProxy 1.7 (we have tried 1.7.5, 1.7.6 and 1.7.7)

Our backends are using NodeJs 6 and what happens is that we get log lines like this:

2017-07-05T07:26:04.205735+00:00 haproxy haproxy[6034]: ERR [05/Jul/2017:07:26:04.141] frontend backend/server 0/0/0/63/63 200 11833 - - SDNN 271/270/23/1/0 0/0 {Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2228.0 Safari/537.36} {} “GET /boletimseptufpr/docs/04.2017_boletim HTTP/1.0”

So when I go and look at the corresponding NodeJs log, I see the request and a a http status code 200 being returned and this is also what I see in the haproxy log - http status code 200 - so how can it be an haproxy ERR and session state SD and at the same time be http status code 200 ??? I don’t get it :slight_smile:

Anyone here who can explain how it can be http status code 200 and at the same time an ERR

Switching back to version 1.6.8 and the errors disappear.


Simon Ellefsen,


Could be related to the following thread, can you try the patch?




I have implemented the patch but it introduced another more serious problem, the browser was not getting any data (almost).

A request that would normally return around 25kb now returns ~300 bytes (just the headers, empty body), status code 200

Simon Ellefsen,


Christopher Faulet is working on this:


This was properly fixed in 1.8-dev now (already committed). Can you try the new patch for 1.7?


If mail-archive messed the patch up, here’s a pastebin copy of it:


The previous patch contains a bug, Here is the new one : https://pastebin.com/raw/JkBqaitq


I/we have been running (v1.7.8 with the patch) now for 5-6 hours without seeing any of the previous mentioned errors/issues. It seems to work.

Many thanks

Simon Ellefsen,


Thanks for your feedback !


Hi there,

The bug seem to have resurfaced in HAProxy 1.8.3.
I have also verfied it in version 1.9dev0

The bug is not present in 1.7.9.


This issue has resurfaced in HAProxy 1.8.3 and everything above it it seems.
I also see it in version 1.9dev0.