Hey Baptiste,
Thank you for looking into it.
The bug is triggered by running haproxy with the following config:
global
maxconn 32000
tune.maxrewrite 2048
user haproxy
group haproxy
daemon
chroot /var/lib/haproxy
nbproc 1
maxcompcpuusage 85
spread-checks 0
stats socket /var/run/haproxy.sock mode 600 level admin process 1 user
haproxy group haproxy
server-state-file test
server-state-base /var/run/haproxy/state
master-worker no-exit-on-failure
defaults
load-server-state-from-file global
log global
timeout http-request 5s
timeout connect 2s
timeout client 300s
timeout server 300s
mode http
option dontlog-normal
option http-server-close
option redispatch
option log-health-checks
listen stats
bind :1936
bind-process 1
mode http
stats enable
stats uri /
stats admin if TRUE
listen banaan-443-ipv4
bind :443
mode tcp
server banaan-vps 127.0.0.1:443 check inter 2000
- Then start haproxy (it will do healthchecks to port 443)
- change server banaan-vps 127.0.0.1:443 check inter 2000 to server banaan-vps
127.0.0.1:80 check inter 2000
- save the state using /bin/sh -c "echo show servers state | /usr/bin/socat
/var/run/haproxy.sock - > /var/run/haproxy/state/test" (this is normally done
using the systemd file on reload, see initial mail)
- reload haproxy (it still does healthchecks to port 443 while port 80 was
expected)
if you delete the statefile and reload haproxy it will start healthchecks for
port 80 as expected
-Sven
________________________________
Van: Baptiste <[email protected]>
Verzonden: dinsdag 3 juli 2018 11:38:14
Aan: Sven Wiltink
CC: [email protected]
Onderwerp: Re: haproxy bug: healthcheck not passing after port change when
statefile is enabled
Hi Sven,
Thanks a lot for your feedback!
I'll check how we could handle this use case with the state file.
Just to ensure I'm going to troubleshoot the right issue, could you please
summarize how you trigger this issue in a few simple steps?
IE:
- conf v1, server port is X
- generate server state (where port is X)
- update conf to v2, where port is Y
reload HAProxy => X is applied, while you expect to get Y instead
Baptiste
On Mon, Jun 25, 2018 at 12:55 PM, Sven Wiltink
<[email protected]<mailto:[email protected]>> wrote:
Hello,
So we've dug a little deeper and the issue seems to be caused by the port value
in the statefile. When the target port of a server has changed between reloads
the port specified in the state file is leading. When running tcpdump you can
see the healthchecks are being performed for the old port. After stopping
haproxy and removing the statefile the healthcheck is performed for the right
port. When manually editing the statefile to a random port the healthchecks
will be performed for that port instead of the one specified by the config.
The code responsible for this is line
http://git.haproxy.org/?p=haproxy-1.8.git;a=blob;f=src/server.c;h=523289e3bda7ca6aa15575f1928f5298760cf582;hb=HEAD#l2931
from commit
http://git.haproxy.org/?p=haproxy-1.8.git;a=commitdiff;h=3169471964fdc49963e63f68c1fd88686821a0c4.
A solution would be invalidating the state when the ports don't match.
-Sven
________________________________
Van: Sven Wiltink
Verzonden: dinsdag 12 juni 2018 17:01:18
Aan: [email protected]<mailto:[email protected]>
Onderwerp: haproxy bug: healthcheck not passing after port change when
statefile is enabled
Hello,
There seems to be a bug in the loading of state files after a configuration
change. When changing the destination port of a server the healthchecks never
start passing if the state before the reload was down. This bug has been
introduced after 1.7.9 as we cannot reproduce it on machines running that
version of haproxy. You can use the following steps to reproduce the issue:
Start with a fresh debian 9 install
install socat
install haproxy 1.8.9 from backports
create a systemd file
/etc/systemd/system/haproxy.service.d/60-haproxy-server_state.conf with the
following contents:
[Service]
ExecStartPre=/bin/mkdir -p /var/run/haproxy/state
ExecReload=
ExecReload=/usr/sbin/haproxy -f ${CONFIG} -c -q $EXTRAOPTS
ExecReload=/bin/sh -c "echo show servers state | /usr/bin/socat
/var/run/haproxy.sock - > /var/run/haproxy/state/test"
ExecReload=/bin/kill -USR2 $MAINPID
create the following files:
/etc/haproxy/haproxy.cfg.disabled:
global
maxconn 32000
tune.maxrewrite 2048
user haproxy
group haproxy
daemon
chroot /var/lib/haproxy
nbproc 1
maxcompcpuusage 85
spread-checks 0
stats socket /var/run/haproxy.sock mode 600 level admin process 1 user
haproxy group haproxy
server-state-file test
server-state-base /var/run/haproxy/state
master-worker no-exit-on-failure
defaults
load-server-state-from-file global
log global
timeout http-request 5s
timeout connect 2s
timeout client 300s
timeout server 300s
mode http
option dontlog-normal
option http-server-close
option redispatch
option log-health-checks
listen stats
bind :1936
bind-process 1
mode http
stats enable
stats uri /
stats admin if TRUE
/etc/haproxy/haproxy.cfg.different-port:
global
maxconn 32000
tune.maxrewrite 2048
user haproxy
group haproxy
daemon
chroot /var/lib/haproxy
nbproc 1
maxcompcpuusage 85
spread-checks 0
stats socket /var/run/haproxy.sock mode 600 level admin process 1 user
haproxy group haproxy
server-state-file test
server-state-base /var/run/haproxy/state
master-worker no-exit-on-failure
defaults
load-server-state-from-file global
log global
timeout http-request 5s
timeout connect 2s
timeout client 300s
timeout server 300s
mode http
option dontlog-normal
option http-server-close
option redispatch
option log-health-checks
listen stats
bind :1936
bind-process 1
mode http
stats enable
stats uri /
stats admin if TRUE
listen banaan-443-ipv4
bind :443
mode tcp
server banaan-vps 127.0.0.1:80<http://127.0.0.1:80> check inter 2000
listen banaan-80-ipv4
bind :80
mode tcp
server banaan-vps 127.0.0.1:80<http://127.0.0.1:80> check inter 2000
/etc/haproxy/haproxy.cfg.same-port:
global
maxconn 32000
tune.maxrewrite 2048
user haproxy
group haproxy
daemon
chroot /var/lib/haproxy
nbproc 1
maxcompcpuusage 85
spread-checks 0
stats socket /var/run/haproxy.sock mode 600 level admin process 1 user
haproxy group haproxy
server-state-file test
server-state-base /var/run/haproxy/state
master-worker no-exit-on-failure
defaults
load-server-state-from-file global
log global
timeout http-request 5s
timeout connect 2s
timeout client 300s
timeout server 300s
mode http
option dontlog-normal
option http-server-close
option redispatch
option log-health-checks
listen stats
bind :1936
bind-process 1
mode http
stats enable
stats uri /
stats admin if TRUE
listen banaan-443-ipv4
bind :443
mode tcp
server banaan-vps 127.0.0.1:443<http://127.0.0.1:443> check inter 2000
listen banaan-80-ipv4
bind :80
mode tcp
server banaan-vps 127.0.0.1:80<http://127.0.0.1:80> check inter 2000
start a netcat process to fake a webserver: nc -klp 80
cp haproxy.cfg.disabled to haproxy.cfg and start haproxy.
cp haproxy.cfg.same-port to haproxy.cfg and reload haproxy. You will now see
that the servers for banaan-443-ipv4 are marked as down, as expected (nothing
is running on port 443).
Now cp haproxy.cfg.different-port to haproxy.cfg and reload haproxy again.
banaan-443-ipv4 will still be marked as down, although it uses the same
healthcheck as the port 80 configuration: server banaan-vps
127.0.0.1:80<http://127.0.0.1:80> check inter 2000
If we now stop haproxy and delete the statefile located at
/var/run/haproxy/state/test and start haproxy again the server will be marked
as up.
Thanks in advance,
Sven
