Re: HAProxy - 504 Gateway Timeout error.
Willy Tarreau w at 1wt.eu writes: Hi, On Thu, Jul 14, 2011 at 10:21:56AM +, gidot wrote: Thanks Willy, I managed to fix the problem with the log. It's due to my entry in /etc/ syslogd.conf. This thread http://www.serverphorums.com/read.php? 10,127228,127867 helped me out :). Here is the excerpt of my haproxy.log. Hope someone can enlighten me if there's anything obvious from this log that can help me to troubleshoot my problem. Here's from grep'ing 504: Jul 13 20:37:57 localhost haproxy[98507]: 213.47.109.71:51261 [13/ Jul/2011:20:37:07.967] webjailfarm webjailfarm/wj01 7/0/0/-1/+50009 504 +194 - - sHVN 62/62/52/12/0 0/0 GET /main.php?location=war HTTP/1.1 (...) All of these logs indicate that the server is simply not responding within 50 seconds. As frustrating as this can be, this is something quite common when servers get overloaded or when they try to access a locked resource. The two following ones however are more concerning : Jul 13 20:41:25 localhost haproxy[98507]: 188.123.218.31:4180 [13/ Jul/2011:20:40:35.132] webjailfarm webjailfarm/wj08 2/0/0/-1/+50005 504 +194 - - sHVN 78/78/61/4/0 0/0 GET /images/gamefavicons.png HTTP/1.1 Jul 13 20:43:36 localhost haproxy[98507]: 217.246.8.81:2284 [13/ Jul/2011:20:42:46.796] webjailfarm webjailfarm/wj05 1/0/0/-1/+50003 504 +194 - - sHVN 56/56/46/0/0 0/0 GET /emptyicon.gif HTTP/1.1 I think that such resources are purely static and have no reason not to be quickly delivered. Is there any possibility that the same servers are accessed via other backend sections, or even directly without passing via haproxy ? I'm asking because what I suspect is that the server's connection limit is reached due to other activity, but the listening socket is not yet saturated, so our request lies in the server's backlog until a connection is released so that a process (or thread) can process the pending request (which did not happen in time here). And some others: Jul 13 20:38:08 localhost haproxy[98507]: 89.228.101.118:51199 [13/ Jul/2011:20:38:08.893] webjailfarm webjailfarm/wj05 0/0/-1/-1/+1 503 +212 - - SCDN 44/44/37/7/+3 0/0 POST /login.php HTTP/1.1 The connection was referencing a server which was already detected as DOWN (hence the D flag), so the health checks have noticed the event. The connection was redispatched onto another server (wj05) but the connection failed there. It could be the same thing as above, but with the backlog full, so the system is rejecting extra connections instead of queuing them. It could also be that you restarted the server and the connections were attempted while the port was not bound. Jul 13 20:38:14 localhost haproxy[98507]: 188.101.27.150:61567 [13/ Jul/2011:20:38:14.883] webjailfarm webjailfarm/wj06 13/0/1/-1/+14 502 +204 - - SHVN 53/53/47/7/0 0/0 GET /js/scriptaculous.js?load=effects,slider HTTP/1.1 The 502s normally indicate that the server broke the connection without responding. This can be the consequence of a server restart as well as it can indicate dying processes. At the moment we're still having problems with clients receiving 502 and 504 errors. It was quiet for the first few days after we have tuned the box, but since 2 days ago, they're back. If you check your stats page, you should see that your servers state are changing a lot. A server must not flap, it must have a steady state. In my opinion, the fact that they're seen down is not the cause of the problem but one of the consequences : something is blocking your servers or making them process requests slowly and at one point they can't even process health checks anymore. Requests are aborted on timeouts and checks fail, causing the server to be marked down. This is normally what happens when servers connection limit gets overflown. You may want to try to increase your MaxClients or equivalent. Be careful though, as this can imply a higher memory usage. Another solution people generally like is to split dynamic/static contents, which is called content switching. You build a farm out of a very fast and scalable server such as nginx and send the static requests there. You keep the rest on current servers, the load should drop quite a bit. Btw, I tried to run the command echo show sess | socat stdio /var/run/ haproxy/ haproxy.sock, and some entries show that it's not forwarding to any server (none). Is this normal? [/root] # echo show sess | socat stdio /var/run/haproxy/haproxy.sock 0x800fbfc00: proto=tcpv4 src=178.190.178.184:52094 fe=webjailfarm be=webjailfarm srv=none ts=02 age=46s calls=1 rq [f=501000h,l=0,an=0eh,rx=3s,wx=,ax=] rp[f=001000h,l=0,an=00h,rx=,wx=,ax=] s0= [7,18h,fd=55,ex=] s1=[0,0h,fd=-1,ex=] exp=3s (...) It is normal for connections which have not yet sent a full request. In your case, the request buffer is empty so nothing was received from the client. Until you don't see
HAProxy - 504 Gateway Timeout error.
Thanks Willy, I managed to fix the problem with the log. It's due to my entry in /etc/ syslogd.conf. This thread http://www.serverphorums.com/read.php? 10,127228,127867 helped me out :). Here is the excerpt of my haproxy.log. Hope someone can enlighten me if there's anything obvious from this log that can help me to troubleshoot my problem. Here's from grep'ing 504: Jul 13 20:37:57 localhost haproxy[98507]: 213.47.109.71:51261 [13/ Jul/2011:20:37:07.967] webjailfarm webjailfarm/wj01 7/0/0/-1/+50009 504 +194 - - sHVN 62/62/52/12/0 0/0 GET /main.php?location=war HTTP/1.1 Jul 13 20:38:08 localhost haproxy[98507]: 213.47.109.71:51265 [13/ Jul/2011:20:37:18.348] webjailfarm webjailfarm/wj01 45/0/0/-1/+50047 504 +194 - - sHVN 44/44/37/8/0 0/0 GET /main.php?location=war HTTP/1.1 Jul 13 20:40:10 localhost haproxy[98507]: 2.202.200.168:56122 [13/ Jul 13 20:41:25 localhost haproxy[98507]: 188.123.218.31:4180 [13/ Jul/2011:20:40:35.132] webjailfarm webjailfarm/wj08 2/0/0/-1/+50005 504 +194 - - sHVN 78/78/61/4/0 0/0 GET /images/gamefavicons.png HTTP/1.1 Jul 13 20:43:36 localhost haproxy[98507]: 217.246.8.81:2284 [13/ Jul/2011:20:42:46.796] webjailfarm webjailfarm/wj05 1/0/0/-1/+50003 504 +194 - - sHVN 56/56/46/0/0 0/0 GET /emptyicon.gif HTTP/1.1 Jul 13 20:44:33 localhost haproxy[98507]: 41.141.73.47:2654 [13/ Jul/2011:20:43:43.659] webjailfarm webjailfarm/wj08 21/0/1/-1/+50023 504 +194 - - sHVN 175/175/166/18/0 0/0 GET /getCSS.php?css= %2Fae1%2F68%2F4885%2E1255006208%2E104491%2Ecss HTTP/1.1 Jul 13 20:44:38 localhost haproxy[98507]: 87.160.231.110:4937 [13/ Jul/2011:20:43:48.808] webjailfarm webjailfarm/wj01 16/0/0/-1/+50017 504 +194 - - sHVN 166/166/162/27/0 0/0 GET /main.php? location=ausbildenunitid=5enforcename=yestraincount=20dotraining=yesbase template=0unitname=Drachenritter HTTP/1.1 Jul 13 20:44:42 localhost haproxy[98507]: 41.178.69.109:3476 [13/ Jul/2011:20:43:51.877] webjailfarm webjailfarm/wj04 17/0/0/-1/+50308 504 +194 - - sHVN 182/182/175/37/0 0/0 POST /main.php? location=einheitenmultiple=yesaction=eggsearchunit=2163081confirm=yes HTTP/1.1 Jul 13 20:44:44 localhost haproxy[98507]: 190.165.104.203:1659 [13/ Jul/2011:20:43:54.463] webjailfarm webjailfarm/wj03 16/0/0/-1/+50016 504 +194 - - sHVN 195/195/190/47/0 0/0 GET /main.php HTTP/1.1 Jul 13 20:44:44 localhost haproxy[98507]: 178.190.206.19:51649 [13/ Jul/2011:20:43:54.700] webjailfarm webjailfarm/wj01 11/0/0/-1/+50013 504 +194 - - sHVN 186/186/182/30/0 0/0 GET /actions.php? location=statusaction=markstatusreadcurtime=1310582637630 HTTP/1.1 And some others: Jul 13 20:38:08 localhost haproxy[98507]: 89.228.101.118:51199 [13/ Jul/2011:20:38:08.893] webjailfarm webjailfarm/wj05 0/0/-1/-1/+1 503 +212 - - SCDN 44/44/37/7/+3 0/0 POST /login.php HTTP/1.1 Jul 13 20:38:14 localhost haproxy[98507]: 188.101.27.150:61567 [13/ Jul/2011:20:38:14.883] webjailfarm webjailfarm/wj06 13/0/1/-1/+14 502 +204 - - SHVN 53/53/47/7/0 0/0 GET /js/scriptaculous.js?load=effects,slider HTTP/1.1 Jul 13 20:38:18 localhost haproxy[98507]: 89.228.65.164:49289 [13/ Jul/2011:20:38:18.818] webjailfarm webjailfarm/wj06 4/0/0/-1/+5 502 +204 - - SHVN 50/50/42/3/0 0/0 GET /js/slider.js HTTP/1.1 Jul 13 20:38:19 localhost haproxy[98507]: 2.11.13.226:2047 [13/ Jul/2011:20:38:19.221] webjailfarm webjailfarm/wj08 8/0/-1/-1/+8 503 +212 - - SCDN 51/51/41/6/+3 0/0 GET /templates/templates/fr/langfile.js HTTP/1.1 Jul 13 20:38:29 localhost haproxy[98507]: 217.247.188.220:3081 [13/ Jul/2011:20:38:29.536] webjailfarm webjailfarm/wj05 58/0/0/-1/+58 502 +204 - - SHVN 64/64/54/6/0 0/0 GET /images/de/gbg/cssgroup/standard.css HTTP/1.1 Jul 13 20:38:31 localhost haproxy[98507]: 89.186.148.213:2198 [13/ Jul/2011:20:38:31.764] webjailfarm webjailfarm/wj07 0/0/0/-1/+0 502 +204 - - SHVN 56/56/47/5/0 0/0 GET /js/scriptaculous.js?load=effects,slider HTTP/1.1 At the moment we're still having problems with clients receiving 502 and 504 errors. It was quiet for the first few days after we have tuned the box, but since 2 days ago, they're back. Btw, I tried to run the command echo show sess | socat stdio /var/run/haproxy/ haproxy.sock, and some entries show that it's not forwarding to any server (none). Is this normal? [/root] # echo show sess | socat stdio /var/run/haproxy/haproxy.sock 0x800fbfc00: proto=tcpv4 src=178.190.178.184:52094 fe=webjailfarm be=webjailfarm srv=none ts=02 age=46s calls=1 rq [f=501000h,l=0,an=0eh,rx=3s,wx=,ax=] rp[f=001000h,l=0,an=00h,rx=,wx=,ax=] s0= [7,18h,fd=55,ex=] s1=[0,0h,fd=-1,ex=] exp=3s 0x800fc2600: proto=tcpv4 src=94.222.121.57:18221 fe=webjailfarm be=webjailfarm srv=wj01 ts=08 age=37s calls=6 rq[f=4909000h,l=0,an=00h,rx=13s,wx=,ax=] rp [f=10b020h,l=0,an=00h,rx=,wx=,ax=] s0=[7,10h,fd=11,ex=] s1=[7,18h,fd=7,ex=] exp=13s 0x801a71800: proto=tcpv4 src=178.198.246.35:64612 fe=webjailfarm be=webjailfarm srv=none ts=02 age=34s calls=1 rq[f=501000h,l=0,an=0eh,rx=16s,wx=,ax=] rp [f=001000h,l=0,an=00h,rx=,wx=,ax=] s0=[7,18h,fd=44,ex=]
Re: HAProxy - 504 Gateway Timeout error.
Hi, On Thu, Jul 14, 2011 at 10:21:56AM +, gidot wrote: Thanks Willy, I managed to fix the problem with the log. It's due to my entry in /etc/ syslogd.conf. This thread http://www.serverphorums.com/read.php? 10,127228,127867 helped me out :). Here is the excerpt of my haproxy.log. Hope someone can enlighten me if there's anything obvious from this log that can help me to troubleshoot my problem. Here's from grep'ing 504: Jul 13 20:37:57 localhost haproxy[98507]: 213.47.109.71:51261 [13/ Jul/2011:20:37:07.967] webjailfarm webjailfarm/wj01 7/0/0/-1/+50009 504 +194 - - sHVN 62/62/52/12/0 0/0 GET /main.php?location=war HTTP/1.1 (...) All of these logs indicate that the server is simply not responding within 50 seconds. As frustrating as this can be, this is something quite common when servers get overloaded or when they try to access a locked resource. The two following ones however are more concerning : Jul 13 20:41:25 localhost haproxy[98507]: 188.123.218.31:4180 [13/ Jul/2011:20:40:35.132] webjailfarm webjailfarm/wj08 2/0/0/-1/+50005 504 +194 - - sHVN 78/78/61/4/0 0/0 GET /images/gamefavicons.png HTTP/1.1 Jul 13 20:43:36 localhost haproxy[98507]: 217.246.8.81:2284 [13/ Jul/2011:20:42:46.796] webjailfarm webjailfarm/wj05 1/0/0/-1/+50003 504 +194 - - sHVN 56/56/46/0/0 0/0 GET /emptyicon.gif HTTP/1.1 I think that such resources are purely static and have no reason not to be quickly delivered. Is there any possibility that the same servers are accessed via other backend sections, or even directly without passing via haproxy ? I'm asking because what I suspect is that the server's connection limit is reached due to other activity, but the listening socket is not yet saturated, so our request lies in the server's backlog until a connection is released so that a process (or thread) can process the pending request (which did not happen in time here). And some others: Jul 13 20:38:08 localhost haproxy[98507]: 89.228.101.118:51199 [13/ Jul/2011:20:38:08.893] webjailfarm webjailfarm/wj05 0/0/-1/-1/+1 503 +212 - - SCDN 44/44/37/7/+3 0/0 POST /login.php HTTP/1.1 The connection was referencing a server which was already detected as DOWN (hence the D flag), so the health checks have noticed the event. The connection was redispatched onto another server (wj05) but the connection failed there. It could be the same thing as above, but with the backlog full, so the system is rejecting extra connections instead of queuing them. It could also be that you restarted the server and the connections were attempted while the port was not bound. Jul 13 20:38:14 localhost haproxy[98507]: 188.101.27.150:61567 [13/ Jul/2011:20:38:14.883] webjailfarm webjailfarm/wj06 13/0/1/-1/+14 502 +204 - - SHVN 53/53/47/7/0 0/0 GET /js/scriptaculous.js?load=effects,slider HTTP/1.1 The 502s normally indicate that the server broke the connection without responding. This can be the consequence of a server restart as well as it can indicate dying processes. At the moment we're still having problems with clients receiving 502 and 504 errors. It was quiet for the first few days after we have tuned the box, but since 2 days ago, they're back. If you check your stats page, you should see that your servers state are changing a lot. A server must not flap, it must have a steady state. In my opinion, the fact that they're seen down is not the cause of the problem but one of the consequences : something is blocking your servers or making them process requests slowly and at one point they can't even process health checks anymore. Requests are aborted on timeouts and checks fail, causing the server to be marked down. This is normally what happens when servers connection limit gets overflown. You may want to try to increase your MaxClients or equivalent. Be careful though, as this can imply a higher memory usage. Another solution people generally like is to split dynamic/static contents, which is called content switching. You build a farm out of a very fast and scalable server such as nginx and send the static requests there. You keep the rest on current servers, the load should drop quite a bit. Btw, I tried to run the command echo show sess | socat stdio /var/run/haproxy/ haproxy.sock, and some entries show that it's not forwarding to any server (none). Is this normal? [/root] # echo show sess | socat stdio /var/run/haproxy/haproxy.sock 0x800fbfc00: proto=tcpv4 src=178.190.178.184:52094 fe=webjailfarm be=webjailfarm srv=none ts=02 age=46s calls=1 rq [f=501000h,l=0,an=0eh,rx=3s,wx=,ax=] rp[f=001000h,l=0,an=00h,rx=,wx=,ax=] s0= [7,18h,fd=55,ex=] s1=[0,0h,fd=-1,ex=] exp=3s (...) It is normal for connections which have not yet sent a full request. In your case, the request buffer is empty so nothing was received from the client. Until you don't see too many of them, you don't have to worry, those can be port probes or similar. If you have enabled keep-alive on the client side, it
HAProxy - 504 Gateway Timeout error.
Hi,
We have recently migrated our game servers from Linux to FreeBSD. We have 8
web servers running in jails, with HAProxy as load balancer. We also have
CARP configured in case of network failover.
carp is running as master on the 1st server(webm01), and backup on the 2nd
server(webm02). haproxy on both servers are actively running, though only
one is working at a time, depending on which server with carp acting as
master. Both servers have pf running as well.
We are running FreeBSD 8.2-RELEASE, haproxy-1.4.15, apache-2.2.19 and the
game is php coded.
Our network architecture is as follows. There is a backend database running
as well on a jail in a different server, which I excluded from the diagram
(hope the ascii diagram will be displayed well in the mail):
+- wj01
|
(webm01) |-- wj02
user carp haproxy --+
| |-- wj03
| |
| +- wj04
|
| +- wj05
| |
| |- wj06
carp haproxy --+
(webm02) |- wj07
|
+- wj08
Our main problem at the moment is a lot of users (more than a hundred users)
have complained that they are getting a 504 Gateway Timeout error. This
normally happens at night (CEST), when most players start playing the game.
However, the load of our servers are consistently low at all time.
At the moment there is no obvious pattern as to when this error occurs.
Here is our haproxy.conf:
global
log /var/run/log local0 notice
maxconn 4096
daemon
chroot /var/run/haproxy
user haproxy
group haproxy
stats socket /var/run/haproxy/haproxy.sock uid 1005 gid 1005
defaults
logglobal
modehttp
optionhttpclose
optionforwardfor
optionhttplog
optiontcplog
optiondontlognull
optiontcpka
retries3
option redispatch
maxconn2000
timeout connect5000
timeout client 5
timeout server5
listenwebjailfarm 78.xx.xx.xx:80
mode http
cookieSERVERID insert nocache indirect
balanceroundrobin
option httpclose
option forwardfor
option httpchk HEAD / HTTP/1.0
stats uri /haproxy-status
stats enable
stats auth admin:password
serverwj01 192.168.30.10:80 http://192.168.30.10/ cookie A weight
10 check inter 2000 rise 2 fall 2
serverwj02 192.168.30.20:80 http://192.168.30.20/ cookie B weight
10 check inter 2000 rise 2 fall 2
serverwj03 192.168.30.30:80 http://192.168.30.30/ cookie C weight
10 check inter 2000 rise 2 fall 2
serverwj04 192.168.30.40:80 http://192.168.30.40/ cookie D weight
10 check inter 2000 rise 2 fall 2
serverwj05 192.168.30.50:80 http://192.168.30.50/ cookie E weight
10 check inter 2000 rise 2 fall 2
serverwj06 192.168.30.60:80 http://192.168.30.60/ cookie F weight
10 check inter 2000 rise 2 fall 2
serverwj07 192.168.30.70:80 http://192.168.30.70/ cookie G weight
10 check inter 2000 rise 2 fall 2
serverwj08 192.168.30.80:80 http://192.168.30.80/ cookie H weight
10 check inter 2000 rise 2 fall 2
##
And here is our pf.conf (the exact same pf is running on webm02, only the
IPs changed accordingly):
### macros
webm01 = 78.xx.xx.xx
db = 10.10.10.101
carp_dev = carp0
ext_if = igb0
jail_if = igb0:0
trusted = { 192.168.30.0/24, 10.10.10.0/24, 78.xx.xx.xx/xx, 85.xx.xx.xx/xx
}
tcp_services = { x, 4949 }
ssh_ports = { x, x, x, x }
icmp_types = { echoreq, unreach }
# jails
wj01 = 192.168.30.10
wj02 = 192.168.30.20
wj03 = 192.168.30.30
wj04 = 192.168.30.40
jails = { $wj01 $wj02 $wj03 $wj04 }
### normalization
scrub in all
### translation
nat on $ext_if from $jails to !10.10.10.0/24 - ($jail_if)
rdr pass on $ext_if inet proto tcp from any to $webm01 port x - $wj01
### ssh redirect
rdr pass on $ext_if inet proto tcp from any to $webm01 port x - $wj02
rdr pass on $ext_if inet proto tcp from any to $webm01 port x - $wj03
rdr pass on $ext_if inet proto tcp from any to $webm01 port x - $wj04
rdr pass on $ext_if inet proto tcp from any to ($carp_dev) port 80 -
$webm01
### filtering - drop incoming everything
block in all
block return
### keep state of outgoing connections
pass out keep state
### skip loopback interface
set skip on { lo0 }
### spoofing protection for all interfaces
block
Re: HAProxy - 504 Gateway Timeout error.
Try adding: optionhttplog under your listen, I am not sure what haproxy does if you say tcplog after saying httplog, so you want to make sure have httplog since those log entries provide more info. Run with option httplog on the listen during the busy time and post some examples of the full log entries for the 504s - obfuscated as needed. There are 6 or 8 fields that should give some clues to loading, timing, tcp connection disposition and other potential issues. If you switch to a frontend/backend config, I think the haproxy stats page provides slightly more info, but I don't use listen so I am not positive. If you have a heavy / page, even HEADs every 2 seconds might be some load (because AFAIK php has to spin the whole page to know if it has changed depending on the frameworks used), maybe not. Remember, load can be low on the machines/jails and they might still be near or at their limit for sockets, file descriptors, etc - so be sure to check those. Also you can obviously watch for the errors as they happen with something like: tail -f /var/run/log | fgrep 504 | more On 7/6/11 2:44 AM, Gi Dot wrote: Hi, We have recently migrated our game servers from Linux to FreeBSD. We have 8 web servers running in jails, with HAProxy as load balancer. We also have CARP configured in case of network failover. carp is running as master on the 1st server(webm01), and backup on the 2nd server(webm02). haproxy on both servers are actively running, though only one is working at a time, depending on which server with carp acting as master. Both servers have pf running as well. We are running FreeBSD 8.2-RELEASE, haproxy-1.4.15, apache-2.2.19 and the game is php coded. Our network architecture is as follows. There is a backend database running as well on a jail in a different server, which I excluded from the diagram (hope the ascii diagram will be displayed well in the mail): +- wj01 | (webm01) |-- wj02 user carp haproxy --+ | |-- wj03 | | | +- wj04 | | +- wj05 | | | |- wj06 carp haproxy --+ (webm02) |- wj07 | +- wj08 Our main problem at the moment is a lot of users (more than a hundred users) have complained that they are getting a 504 Gateway Timeout error. This normally happens at night (CEST), when most players start playing the game. However, the load of our servers are consistently low at all time. At the moment there is no obvious pattern as to when this error occurs. Here is our haproxy.conf: global log /var/run/log local0 notice maxconn 4096 daemon chroot /var/run/haproxy user haproxy group haproxy stats socket /var/run/haproxy/haproxy.sock uid 1005 gid 1005 defaults logglobal modehttp optionhttpclose optionforwardfor optionhttplog optiontcplog optiondontlognull optiontcpka retries3 option redispatch maxconn2000 timeout connect5000 timeout client 5 timeout server5 listenwebjailfarm 78.xx.xx.xx:80 mode http cookieSERVERID insert nocache indirect balanceroundrobin option httpclose option forwardfor option httpchk HEAD / HTTP/1.0 stats uri /haproxy-status stats enable stats auth admin:password serverwj01 192.168.30.10:80 http://192.168.30.10/ cookie A weight 10 check inter 2000 rise 2 fall 2 serverwj02 192.168.30.20:80 http://192.168.30.20/ cookie B weight 10 check inter 2000 rise 2 fall 2 serverwj03 192.168.30.30:80 http://192.168.30.30/ cookie C weight 10 check inter 2000 rise 2 fall 2 serverwj04 192.168.30.40:80 http://192.168.30.40/ cookie D weight 10 check inter 2000 rise 2 fall 2 serverwj05 192.168.30.50:80 http://192.168.30.50/ cookie E weight 10 check inter 2000 rise 2 fall 2 serverwj06 192.168.30.60:80 http://192.168.30.60/ cookie F weight 10 check inter 2000 rise 2 fall 2 serverwj07 192.168.30.70:80 http://192.168.30.70/ cookie G weight 10 check inter 2000 rise 2 fall 2 serverwj08 192.168.30.80:80 http://192.168.30.80/ cookie H weight 10 check inter 2000 rise 2 fall 2 ## And here is our pf.conf (the exact same
Re: HAProxy - 504 Gateway Timeout error.
hi, Your maxconn seems a bit low if you have a lot of clients... Maybe you should try increasing it or at lease increase the queue timeout. As hank said, turn on http log, it will provide you very interesting information about your issue. cheers
