Hi Richard,
Le 26/07/2012 13:46, Richard Stanford a écrit :
This morning I was able to reproduce it even after restarting our
appserver proceses and our haproxy process (which had been up for an
extended period of time - thanks!). When it reproduced, I noticed that
the backend appserver was marked as DOWN in the statistics report even
though the logfiles gave no indication that there were any problems.
Please add "log global" in your backend sections (or in your defaults),
this explains why your log files didn't give you any indication.
After adding this line everywhere (not only in the frontend), you'll see
when servers go UP and DOWN, and why.
This will also probably help us to know what happens.
From the user's experience, the system "hung" waiting for a response
for some 40 seconds and then showed a login screen, which was served
when the "incorrect" backend received a page request. Simply
re-requesting the previous page was successful, as the previously
authenticated backend was shown as UP by that point.
In the logfile we see the following entry at the appropriate time:
Jul 26 06:21:09 localhost haproxy[3853]: 172.25.200.177:3124
[26/Jul/2012:06:21:01.826] secure gui/gui2 4993/0/0/-1/7992 -1 0 - -
CH-- 40/40/1/1/0 0/0 "HEAD /panel/healthcheck.html HTTP/1.1"
From this previous log line, it looks like something becomes slow (your
haproxy server or your backend servers).
Configuration file below in full in case there's something odd:
global
maxconn 20000
tune.bufsize 128000
Wow, are you sure you really want to use such a big buffer size ?
Also, ensure you're running the last stable version of HAProxy
(currently 1.4.21), which fixes a major bug when using a larger buffer
size (it doesn't explain what you observe but it's an advise for more
stability).
For more details :
http://haproxy.1wt.eu/git?p=haproxy-1.4.git;a=commit;h=30297cb17147a8d339eb160226bcc08c91d9530b
defaults
mode http
timeout connect 5s
timeout client 1m
timeout server 10m
option srvtcpka
option http-server-close
option http-pretend-keepalive
option redispatch
option abortonclose
option httpchk HEAD /panel/healthcheck.txt HTTP/1.0
As said at the beginning, please add :
log global
backend gui
balance source
appsession JSESSIONID len 64 timeout 3h
If using cookies is not an issue for your clients, I'd recommend you not
to use "appsession" but "cookie insert" or "cookie prefix" instead.
http://cbonte.github.com/haproxy-dconv/configuration-1.4.html#4-cookie
server gui1 172.25.200.53:8080 check maxconn 2000
server gui2 172.25.200.54:8080 check maxconn 2000
You didn't provide any "timeout check" nor "inter" value.
The default will be 2 seconds, which is maybe too low for your case.
http://cbonte.github.com/haproxy-dconv/configuration-1.4.html#inter
http://cbonte.github.com/haproxy-dconv/configuration-1.4.html#timeout%20check
Hope this helps.
--
Cyril Bonté
