Re: HAProxy: listening port set up and performance

Hi,

On Mon, Jan 19, 2009 at 06:11:13PM -0800, Hsin, Chih-fan wrote:
> Hi, I am new to HAProxy and have questions about the configuration and performance.
>
> I downloaded HAProxy 1.3.15.7 from http://haproxy.1wt.eu/<blocked::http://haproxy.1wt.eu/> to /home/user/Tool
> Unpacked it by "tar xopf name.tar.gz.tar"
> Run "make TARGET=linux26"
>
> 1) Apache HTTP testing
> Servers webA (192.168.5.4) and webB (192.168.5.5) have Apache server started.
> Client (192.168.5.1) sends http requests to webA (192.168.5.4:80) and webB (192.168.5.5:80), and can get valide http response (default Apache response).
> [client] -> [webA],[webB]
>
> Now, the HAProxy does not have Apache server and has IP address 192.168.5.3.
> At HAProxy, run "./haproxy -f ./haproxy1.cfg". The haproxy1.cfg is below
> [client] -> [HAProxy] -> [webA],[webB].
> Client sends http request to HAProxy via IE web browing to http://192.168.5.3. However, the client cannot get web response.

By this, do you mean that no response ever comes back, or that you get an error ?

> Client sends http request to HAProxy via multiple IE web browsing to http://192.168.5.3:80. Then it works.

Are you sure that your apache machines don't block access from haproxy ? Also, do you have any form of virtual hosting on those machines, which would refuse requests with a "Host:" field with a wrong IP address in it ?

> haproxy1.cfg file
> listen webfarm 192.168.5.3:80 <- How do I decide the correct port number to make http://192.168.5.3 work?

This is the correct form.

> mode http
> balance roundrobin
> cookie SERVERID insert indirect
> stats enable
> server webA 192.168.5.4:80 cookie A check
> server webB 192.168.5.5:80 cookie B check

I see that you have not configured timeouts. This is bad (though it should not cause you the problem you're seeing). Please add the following lines to the section above :

	timeout client 30s
	timeout server 30s
	timeout connect 5s

Also, you should log, you would see in the logs what is wrong. For this, please add the following line :

        log 127.0.0.1 local0

Then ensure that your syslogd listens to the UDP socket (syslogd -r), and check the log files (you will see one line added when you start haproxy, then one line per request).

> 2) TCP testing (using Iperf)
> Servers webA (192.168.5.4) and webB (192,168.5.5) run Iperf TCP sink to listen to port 5001
> Client runs 2 Iperf TCP connections and send traffic to 192.168.5.3:80
> At HAProxy, run "./haproxy -f ./haproxy2.cfg"
> haproxy2.cfg
> listen webfarm 192.168.5.3:80
> mode tcp
> balance roundrobin
> stats enable
> server webA 192.168.5.4:5001
> server webB 192.168.5.5:5001
> I can achieve 36Mbps each under the following scenario.
> [client] -> 36Mbps -> [webA]
> |----->36Mbps -> [webB]

36 Mbps ??? You definitely have something wrong in your setup ! This is the bandwidth you could expect from a saturated 100 Mbps HUB at maximal collision rate !!! Please check that all your connections are made to a switch and not a hub, and that all your hosts have negociated full duplex (with ethtool).

> However, when I use HAProxy, I can only achieve 18Mbps each. The utilization of HAProxy machine is low.
> [client] -> [HAProxy] -> 18Mbps -> [webA]
> |--------> 18Mbps -> [webB]
> Is this normal? Is there any way to improve it?

No it's not normal, but expected from the bad numbers above. If you are using a hub which is saturated, then making the traffic pass twice over it will half the per-host bandwidth.

Right now, it does not make sense to use a hub for network testing, not even a 100 Mbps switch. Gigabit switches are very cheap, you can find a 5-port gig switch for less than $50, it could save you a lot of time spent troubleshooting connectivity issues.

Regards,
Willy Received on 2009/01/20 05:26