tdb_lock failed (was Re: ... domain authentication?)
jra at samba.org
Mon Oct 27 20:42:35 GMT 2003
On Mon, Oct 27, 2003 at 03:29:15PM -0500, Brandon Craig Rhodes wrote:
> Following your advice, Andrew, I was able to convince our admins that
> we should simply throw all of our servers into the same domain and not
> trying to keep the domains separate. Thanks!
> Now we are having extensive problems with performance in the labs we
> are attempting to move to domain authentication under Samba-3, because
> of contention over the secrets.tdb file from which each thread must
> now fetch the SID for our domain controller; errors look like:
> tdb_chainlock_with_timeout_internal: alarm (10) timed out for key <PDC> in tdb /usr/local/samba-3.0.0/private/secrets.tdb
> where <PDC> is the name of the primary domain controller.
> This is happening in two different labs under both Solaris 2.7 and 2.8
> and renders samba-3 essentially unusable. In one lab we have compiled
> Samba with tdb spin locks instead, which solves the problem, but (if I
> understand the relevant warnings correctly) makes us vulnerable to an
> unusable secrets file if a thread dies while having the file locked.
> The /usr/local hierarchy is locally mounted on both systems.
> Has anyone else ever seen this? Meanwhile I suppose I shall try
> having to determine who is holding the problem locks. The lsof
> command shows every samba child process (but not the parent) having a
> read lock on the secrets file, but does not give details as to where
> in the file they are.
Ok, do you have the Sun patch for the "thundering herd" problem with
fcntl locks ? This is common on Solaris systems, they have a problem
with wakeup of many threads waiting on an fcntl lock.
There are references to the patch ID in the Samba mail archives (on
Samba-technical I think).
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