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haproxy bug: healthcheck not passing after port change when statefile is enabled

Posted by Sven Wiltink 
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 check inter 2000
listen banaan-80-ipv4
bind :80
mode tcp
server banaan-vps 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 check inter 2000
listen banaan-80-ipv4
bind :80
mode tcp
server banaan-vps 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 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
Sven,

Am 12.06.2018 um 17:01 schrieb Sven Wiltink:
> 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

While this would not have an effect on your issue I suggest specifying
RuntimeDirectory to save the manual `mkdir` and manual clean up:

> # /lib/systemd/system/haproxy.service.d/state.conf
> [Service]
> RuntimeDirectory=haproxy
> ExecReload=
> ExecReload=/usr/sbin/haproxy -f $CONFIG -c -q $EXTRAOPTS
> ExecReload=/bin/sh -c "echo show servers state |nc -U /var/run/haproxy/admin.sock > /run/haproxy/global-state"
> ExecReload=/bin/kill -USR2 $MAINPID

The RuntimeDirectory would automatically be cleaned on `restart` /
`stop`, but not on a `reload`. If this is not wanted take a look at
`RuntimeDirectoryPreserve`
(https://www.freedesktop.org/software/systemd/man/systemd.exec.html#RuntimeDirectoryPreserve=).

Best regards
Tim Düsterhus
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: haproxy@formilux.org
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 check inter 2000
listen banaan-80-ipv4
bind :80
mode tcp
server banaan-vps 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 check inter 2000
listen banaan-80-ipv4
bind :80
mode tcp
server banaan-vps 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 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
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]> 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=523289e3bda7ca6aa15575f1928f52
> 98760cf582;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:* haproxy@formilux.org
> *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 check inter 2000
> listen banaan-80-ipv4
> bind :80
> mode tcp
> server banaan-vps 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 check inter 2000
> listen banaan-80-ipv4
> bind :80
> mode tcp
> server banaan-vps 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
> 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
>
>
>
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: haproxy@formilux.org
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 127.0.0.1:80http://127.0.0.1:80 check inter 2000
listen banaan-80-ipv4
bind :80
mode tcp
server banaan-vps 127.0.0.1:80http://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 127.0.0.1:443http://127.0.0.1:443 check inter 2000
listen banaan-80-ipv4
bind :80
mode tcp
server banaan-vps 127.0.0.1:80http://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 127.0.0.1:80http://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
Hi Sven,

Thanks for the clarification.
It's a bit more complicated than what it is supposed to be.
I think we may want to apply the port only if it has been changed at
runtime (changed by DNS SRV records).

The status is the following: I have a pending patch which brings SRV record
information into the state file. (WIP, but last mile)
Once it has been merged, we'll be able to fix this issue (by applying the
port only when the server is being managed by an SRV record).

Baptiste


On Tue, Jul 3, 2018 at 3:41 PM, Sven Wiltink <[email protected]> wrote:

> 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:* haproxy@formilux.org
> *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]>
> 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=hapr
> oxy-1.8.git;a=blob;f=src/server.c;h=523289e3bda7ca6aa15575f1
> 928f5298760cf582;hb=HEAD#l2931
>
> from commit http://git.haproxy.org/?p=haproxy-1.8.git;a=commitdiff;h=316
> 9471964fdc49963e63f68c1fd88686821a0c4.
>
>
> 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:* haproxy@formilux.org
> *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.se
> rvice.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 check inter 2000
> listen banaan-80-ipv4
> bind :80
> mode tcp
> server banaan-vps 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 check inter 2000
> listen banaan-80-ipv4
> bind :80
> mode tcp
> server banaan-vps 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
> 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
>
>
>
>
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