[Linux-cluster] Trying to locate the bottleneck

[Raymond Setchfield]

Hi Jeff

Many Thanks for your reply.

I have had a look to see if there if there is anything suspicious within 
dmesg and within messages and unfortunately there isn't anything at all 
apart from one timeout.

Jul  8 10:15:51 loadbalancer-01 nanny[5427]: [inactive] shutting down 
192.168.10.36:80 due to connection failure
Jul  8 10:16:03 loadbalancer-01 nanny[5427]: [ active ] making 
192.168.10.36:80 available

I'll check out the possibility of any network related issues which may 
cause this problem though.

Thanks for all your help!

R.


Jeff Sturm wrote:
> Hi Raymond,
>
> At those concurrency levels I would suspect network tuning may help.
> Does dmesg show anything interesting on the load balancers during your
> testing?
>
> For high levels of concurrency on a NAT'd firewall or load balancer I
> specifically remember having to adjust ip_conntrack_max upwards.
> Perhaps network buffers as well.
>
> -Jeff
>
>   
>> -----Original Message-----
>> From: linux-cluster-bounces at redhat.com
>>     
> [mailto:linux-cluster-bounces at redhat.com]
>   
>> On Behalf Of Raymond Setchfield
>> Sent: Tuesday, July 07, 2009 8:35 AM
>> To: linux-cluster at redhat.com
>> Subject: [Linux-cluster] Trying to locate the bottleneck
>>
>> Hi
>>
>> I am trying to find a problem here with a setup which I am currently
>> testing.
>>
>> This is the current setup which I have at the moment
>>
>> 15 web farm servers which are running vhost-ldap module and also have
>> ldap caching enabled. Which are behind 2 Load balancer servers which
>>     
> are
>   
>> in fail over. The software which it is currently running is Piranha on
>> the load balancers.
>>
>> I am using siege to get some benchmarking done on these to test
>> basically their availability when pushing high concurrency.
>>
>> At 100 (99.60 according to siege) Concurrent Connection it appears to
>>     
> be
>   
>> all ok with 99.89%. At 120 (119.52 according to siege) Concurrent
>> connections I get 99.9%, and at 130 (129.51 according to siege)
>> Concurrent Connections I get 100% availability.
>>
>> However pushing it any further than this, for example 150 concurrent
>> connections it is falling over and siege bails out with multiple
>> connection time outs. I am trying to find the bottle neck here and I
>>     
> am
>   
>> wondering if it is software which I am using for the load balancers or
>>     
> a
>   
>> limitation with apache.
>>
>> The command I am using for siege is pretty simple nothing special;
>>
>> siege --concurrent=150 --internet --file=urls.txt --benchmark
>>     
> --time=60M
>   
>> My lvs.cf file can be found here to show you guys the config which I
>>     
> am
>   
>> using.
>>
>> http://pastebin.com/m52d6cc23
>>
>> Any help would be greatly appreciated
>>
>> Many Thanks
>>
>> R.
>>
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