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From: Kevin Maziere - Amen <kevin.maziere#amen.fr>
Date: Wed, 05 Mar 2008 17:48:43 +0100

Hi,

For test purpose I'm testing a haproxy loop configuration, all on the same machine.

5 differents instance of webservers, on the same machine, listening on different IP on port 8080.
And 5 differents haproxy listener on port 80

What I want to do :
having haproxy able to switch from an server to another backup server if one failed, and so on until the last instance :

HA1 ->HA2(backup)->HA3(backup)->HA4(backup)->HA5(backup)
HA2 ->HA1(backup)->HA3(backup)->HA4(backup)->HA5(backup)
HA3 ->HA2(backup)->HA1(backup)->HA4(backup)->HA5(backup)
HA4 ->HA2(backup)->HA3(backup)->HA3(backup)->HA5(backup)
HA5 ->HA2(backup)->HA3(backup)->HA4(backup)->HA1(backup)

listen haproxy_1 192.168.0.1:80
maxconn 1000
mode http
cookie JSESSIONID prefix
balance roundrobin

 server s1 192.168.0.1:8080 cookie f1 check inter 2000 fall 4 rise 1
 server s2 192.168.0.2:8080 cookie f2 check inter 10000 fall 4 rise 1 backup
 server f3 192.168.0.3:8080 cookie f3 check inter 10000 fall 4 rise 1 backup
 server f4 192.168.100.4:8080 cookie f4 check inter 10000 fall 4 rise 1

backup
server f5 192.168.100.5:8080 cookie f5 check inter 10000 fall 4 rise 1 backup
option httpchk /test.php
option forwardfor

listen haproxy_2 192.168.0.2:80
maxconn 1000
mode http
cookie JSESSIONID prefix
balance roundrobin

 server s1 192.168.0.1:8080 cookie f1 check inter 10000 fall 4 rise 1 backup
 server s2 192.168.0.2:8080 cookie f2 check inter 2000 fall 4 rise 1
 server f3 192.168.0.3:8080 cookie f3 check inter 10000 fall 4 rise 1 backup
 server f4 192.168.100.4:8080 cookie f4 check inter 10000 fall 4 rise 1

backup
server f5 192.168.100.5:8080 cookie f5 check inter 10000 fall 4 rise 1 backup
option httpchk /test.php
option forwardfor

And the code he repeated like this for all instances.

In fact I wanted to test if I configure my haproxy proxy server a a backup for other haproxy server, themselves as a backup for other haproxy instance ...will it work or do something really nasty.

My haproxy server will loop on haproxy backup servers, which are looping on haproxy backup server... and so on (I hope I'm clear)

In my case it works, If 4 of the five haproxy failed, the last one still works fine, and my test domain still answer, if all failed, haproxy return code 503 and that is fine.

But what I Remarque is even with no traffic (no connection to any of the haproxy) the number of connection grow up... grow I saw such connections ( number depends on the time since haproxy was launched, and of course of the timeout of tcp session, but more than 1000 ...), with the appropriate netstat command :

tcp        0      0 192.168.100.1:8080    192.168.100.1:43304  TIME_WAIT
 0          0          -
tcp        0      0 192.168.100.1:43304    192.168.100.1:8080   IME_WAIT
0          0          -



-------------------------------------------------------------------------

and the same for other IP .2,.3,.4
If I put a interval check lower, for example 2000 on my backup server, then the number of time wait connections grow up faster

First I thought I was the check launched by haproxy, but if it was such check, I should see something like

	IP.1 IP.2
	IP.2 IP.1

Could someone help me to understand what ? I know that using haproxy like the way I'm testing it is not really appropriate ... maybe it is the reason why (all such bad things on the same machine).

Thanks

kevin Received on 2008/03/05 17:48

many TIME_WAIT connection with strange configuration