Sequence number obsession

[Ken Cross]

Jerry:

Yep, agreed on all points.  The problem, though, was the frequency of
updating the sequence number (>20 times/sec was not uncommon).

My patch just suppressed more than one check per second.  Not elegant, but
it sure cut down the noise when doing network traces.  :-)

Ken
________________________________

Ken Cross

Network Storage Solutions
Phone 865.675.4070 ext 31
kcross at nssolutions.com 

> -----Original Message-----
> From: Gerald (Jerry) Carter [mailto:jerry at samba.org] 
> Sent: Wednesday, May 21, 2003 9:50 AM
> To: Ken Cross
> Cc: 'Multiple recipients of list SAMBA-TECHNICAL'
> Subject: Re: Sequence number obsession
> 
> 
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> On Sun, 27 Apr 2003, Ken Cross wrote:
> 
> > Samba-folk:
> > 
> > We seem to be a bit obsessive-compulsive when it comes to getting a 
> > domain's sequence number.  I have network traces where we 
> obtain the 
> > sequence number >20 times within a second.
> > 
> > The "force" argument to refresh_sequence_number in winbindd_cache.c 
> > appears to be true quite often.  Do we really need 
> sub-second updates 
> > of the sequence number?
> > 
> > The patch below to SAMBA_3_0 changes it so that it doesn't 
> update the 
> > sequence number if it is valid and has been updated within the last 
> > second.  Note that this overrides the "force" argument.
> 
> Ken,
> 
> I think the original idea behind forcing an update of the 
> sequence number 
> was to keep the cache straight.  The sequence number opdate 
> is forced to 
> True whenever our local cache fails and we have to query the 
> PDC.  If we 
> don't update the sequence number then we can get a false 
> positive that 
> says a cache entry is out of date.  This is a rough guess 
> since I have 
> just brielfy looked at the code recently.
> 
> 
> 
> 
> cheers, jerry
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