[Samba] optimizing and scaling ntlm_auth

[Volker Lendecke]

On Thu, Sep 11, 2014 at 12:42:19PM -0400, Louis Munro wrote:
> On 2014-09-11, at 10:39 , Volker Lendecke <Volker.Lendecke at SerNet.DE> wrote:
> 
> > We don't gather these statistics right now. Should be simple
> > to do, but right now we don't have that. From a network
> > trace I think I could spot whether a DC was slow overall or
> > whether it was us, but without further code instrumentation
> > I don't have a good idea how to find what you need from
> > logs. tcpdump can do rolling logs, so it's possible to keep
> > the last gigabyte of traffic around an rotate the rest away.
> > It might be worthwhile to run that for a while and later on
> > analyze the sniff in the moment when ntlm_auth was slow.
> 
> 
> Hi Volker,
> 
> I am running a rolling capture right-now.
> 
> Do you have any pointers regarding what I should be looking for especially?

Well, it's important to match up when it was slow with rough
packet numbers. Then we can see whether RPC requests hung,
whether those were TCP level problems or such things. If
none of these happened when it was slow, we could see that
winbind just did not ask anything. This would finger-point
either at winbind or at the network or at the DC.

Volker

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