[Samba] winbindd performance tunning?

xx77009833

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Mar 13, 2013, 12:20:02 AM3/13/13

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Hi,

Thanks in advanced.

I have written a winbindd client which communicates with winbindd to do NTLM authentication.
However, it seems that the performance of winbindd is low.
I have two questions.
1. seems winbindd is asynchronous? If yes, I think its performance should be higher.
2. do you any suggestion of winbindd performance tunning? Is there any configuration item or anything useful?

Thanks and I will appreciate any of your help.

Xin.

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xx77009833

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Mar 13, 2013, 12:30:02 AM3/13/13

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Volker Lendecke

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Mar 13, 2013, 6:00:01 AM3/13/13

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On Wed, Mar 13, 2013 at 11:51:25AM +0800, xx77009833 wrote:
> Hi,
>
>
> Thanks in advanced.
>
>
> I have written a winbindd client which communicates with winbindd to do NTLM authentication.
> However, it seems that the performance of winbindd is low.
> I have two questions.
> 1. seems winbindd is asynchronous? If yes, I think its
> performance should be higher.
> 2. do you any suggestion of winbindd performance tunning?
> Is there any configuration item or anything useful?

What version are you using? What exactly is slow? Is winbind
chewing CPU? Have you measured where the time is spent? It
might well be the DC or the network is slow. We need more
information here.

With best regards,

Volker Lendecke

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xx77009833

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Mar 13, 2013, 2:00:02 PM3/13/13

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Thank you for your reply:)

Winbindd version is 3.5.8, it runs on a 8 core CPUs machine, and my DC(win2k8) runs on a 4 core CPUs machine.
"performance is slow" means, the transaction per second is around 200. I think it is slow and should be better.
The CPU usage of winbindd is not high. I suspect that winbindd doesn't processing the request in parallel or it is blocked by some internal synchronous operation. But I am not sure.
Till now, I have not profiled winbindd to find where the time is spent......

They all run over my local-area network. So I think network is fast enough
and I suppose DC is not the bottleneck under such pressure:)
BTW.
I found there is a macro WINBINDD_MAX_CLIENTS, and I modified it to 20000. All tests have been done under this condition.

So, the question,
Any suggestion of winbindd performance tunning?
Will it be helpful by using samba4? Is it fully asynchronous internally?

appreciate your help very much!

Xin.

Volker Lendecke

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Mar 14, 2013, 3:30:01 AM3/14/13

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On Thu, Mar 14, 2013 at 01:25:06AM +0800, xx77009833 wrote:
> Winbindd version is 3.5.8, it runs on a 8 core CPUs
> machine, and my DC(win2k8) runs on a 4 core CPUs machine.
> "performance is slow" means, the transaction per second is
> around 200. I think it is slow and should be better.

200 ntlm auth requests per second is not too bad in 3.5.8 I
guess. 3.6.12 has a "winbind max domain connections" which
allows you to open more than one connection to the DC. You
should try that.

> The CPU usage of winbindd is not high. I suspect that
> winbindd doesn't processing the request in parallel or it
> is blocked by some internal synchronous operation. But I
> am not sure.
> Till now, I have not profiled winbindd to find where the time is spent......

My guess would be that it's the DC. Can you wireshark the
network to the DC and analyze the response time there?

Volker