André Warnier wrote:
> Hi.
>
> I know next to nothing about load balancing per se, so this will be a
> very naive question related to the data below : does it matter ?
> I mean, I can see that the load appears to be uneven, but the grand
> total seems to be about 10% of the available cpu time.
I am only showing an example with a few users, but I can drive the load
up to 100% CPU utilization. I expect the server to hold well in any
case. At low user level I expect the load to be even, so I get the best
possible response.
> So do you really care if one instance is using 4% and another 0.4% if
> there is still 90% available in total ?
>
> I am also wondering if what is shown down there is not just this
> phenomenon : whenever the load balancer has to decide to which
> back-end to pass a request, I suppose it checks first which ones are
> already busy.
no, it should round-robin, no matter what is the current load in each od
the app. servers. That is the algorithm I am using.
> Since in this case the total load is light and most of them are always
> free, it might just take the first of the list, which then ends up
> more used than the others. No ?
>
> André
>
>
> fernando castano wrote:
>> Hi all,
>>
>> I'm new to apache. I am experiencing a problem with apache load
>> balancer. I configured the load balancer across 10 app servers
>> (glassfish domains), but when I see the way the cookies (and load)
>> are distributed I see a very uneven distribution. Here is my proxy
>> configuration:
>>
>>
>> fc112959@(protected)
>> # configuration for clustering more then one glassfish
>> ProxyPass / balancer://cluster/ stickysession=JSESSIONID nofailover=Off
>> ProxyPassReverse / http://kenstgapp01:8080
>> ProxyPassReverse / http://kenstgapp01:8280
>> ProxyPassReverse / http://kenstgapp01:8380
>> ProxyPassReverse / http://kenstgapp01:8480
>> ProxyPassReverse / http://kenstgapp01:8580
>> ProxyPassReverse / http://kenstgapp01:8780
>> ProxyPassReverse / http://kenstgapp01:8880
>> ProxyPassReverse / http://kenstgapp01:8980
>> ProxyPassReverse / http://kenstgapp01:9080
>> ProxyPassReverse / http://kenstgapp01:9180
>> <Proxy balancer://cluster/ >
>> BalancerMember http://kenstgapp01:8080 route=kenstgapp01_8080
>> loadfactor=1
>> BalancerMember http://kenstgapp01:8280 route=kenstgapp01_8280
>> loadfactor=1
>> BalancerMember http://kenstgapp01:8380 route=kenstgapp01_8380
>> loadfactor=1
>> BalancerMember http://kenstgapp01:8480 route=kenstgapp01_8480
>> loadfactor=1
>> BalancerMember http://kenstgapp01:8580 route=kenstgapp01_8580
>> loadfactor=1
>> BalancerMember http://kenstgapp01:8780 route=kenstgapp01_8780
>> loadfactor=1
>> BalancerMember http://kenstgapp01:8880 route=kenstgapp01_8880
>> loadfactor=1
>> BalancerMember http://kenstgapp01:8980 route=kenstgapp01_8980
>> loadfactor=1
>> BalancerMember http://kenstgapp01:9080 route=kenstgapp01_9080
>> loadfactor=1
>> BalancerMember http://kenstgapp01:9180 route=kenstgapp01_9180
>> loadfactor=1
>> </Proxy>
>> fc112959@(protected)$
>>
>> And here is how the load gets distributed across jmeter 10 clients:
>> as you can see, only 7 of the jvms get work, and among them the
>> amount of work they do is very uneven (second to last entry in each
>> row is % of cpu used by the process).
>> These domains are exactly the same. I've checked the cookie
>> distribution and reflects the load distribution (uneven). If I
>> increase clients I eventually get work in all jvms (still uneven),
>> and that just proves that all jvms can be routed thru apache load
>> balancer. I am generating load with jmeter. Any hints of what am I
>> doing wrong? how to fix it?
>>
>>
>> PID USERNAME SIZE RSS STATE PRI NICE TIME CPU
>> PROCESS/NLWP 1388 root 3338M 3257M sleep 0 0
>> 9:08:45 6.5% java/89
>> 1414 root 3332M 3253M cpu28 0 0 7:32:01 4.2% java/92
>> 1417 root 3333M 3253M cpu9 0 0 7:14:39 2.3% java/96
>> 1424 root 3332M 3254M cpu12 0 0 7:03:12 2.2% java/89
>> 1420 root 3332M 3254M cpu6 0 0 7:35:40 2.1% java/89
>> 1411 root 3333M 3253M cpu29 0 0 7:31:31 1.9% java/87
>> 3461 webservd 40M 32M sleep 0 0 0:00:03 0.3% httpd/1
>> 3460 webservd 36M 26M sleep 0 0 0:00:03 0.3% httpd/1
>> 3462 webservd 36M 26M sleep 0 0 0:00:03 0.3% httpd/1
>> 3457 webservd 32M 27M cpu24 0 0 0:00:02 0.3% httpd/1
>> 1423 root 3333M 3256M sleep 0 0 7:00:01 0.2% java/88
>> 3348 webservd 40M 32M sleep 0 0 0:00:04 0.2% httpd/1
>> 995 root 3536K 3072K sleep 100 - 0:00:46 0.1% cpustat/33
>> 1360 webservd 43M 35M sleep 0 0 0:00:14 0.1% httpd/1
>> 1337 webservd 43M 35M sleep 0 0 0:00:13 0.1% httpd/1
>> 3559 webservd 13M 11M cpu20 0 0 0:00:00 0.1% hgwebdir.cgi/1
>> 883 root 3848K 3832K cpu25 0 0 0:00:13 0.1% prstat/1
>> 1011 webservd 43M 36M sleep 0 0 0:00:15 0.1% httpd/1
>> 77 webservd 9016K 7832K sleep 0 0 0:16:18 0.1% memcached/1
>> Total: 166 processes, 1525 lwps, load averages: 10.00, 10.20, 10.03
>>
>> TIA,
>> fdo
>>
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