samba - Dec 2018 - Winbindd (tdb_chainlock_with_timeout_internal: alarm (40) timed out for key)

On Wed, 19 Dec 2018 12:32:45 +0530
Amit Kumar via samba <samba at lists.samba.org> wrote:
> Hey,
> 
> But What's the reason of this error?
> 
I do not know, but what I do know is that, if it is a bug, you will
never get it fixed in Samba 4.2.x, this version is EOL. It might also
have been fixed in a later version.

Sorry if this isn't what you want to hear.

Rowland

Hey Rowland,

I wanted to ask

a. What is mutex.tdb, what is its purpose?

b. why "mutex grab failed" started appearing in messages, what can be
the probable reasons?

Is pre-authentication failed related to locking failure of mutex.tdb?


Dec 15 12:49:52 abc winbindd[30467]: [2018/12/15 12:49:52.764924, 0]
../source3/libsmb/cliconnect.c:1921(cli_session_setup_spnego_send)

Dec 15 12:49:52 abc winbindd[30467]: Kinit for ABC$@TYP.ORG
<mailto:AKLRHEMPDP001$@ENTERPRISENET.ORG> to access
cifs/xyz.fgb.net at xyz.NET
<mailto:cifs/CVGWINDOMP011.securityroot.net at SECURITYROOT.NET> failed:
Preauthentication failed

......

Dec 15 08:57:44 abc winbindd[24723]: [2018/12/15 08:57:44.716485, 0]
./source3/lib/util_tdb.c:493(tdb_chainlock_with_timeout_internal)

Dec 15 08:57:44 abc winbindd[24723]:
tdb_chainlock_with_timeout_internal: alarm (40) timed out for key
ABC.typ.org <http://aklwindomp001.enterprisenet.org/> in tdb
/var/lib/samba/mutex.tdb

Dec 15 08:57:44 abc winbindd[24723]: [2018/12/15 08:57:44.716827, 0]
../source3/winbindd/winbindd_cm.c:918(cm_prepare_connection)

Dec 15 08:57:44 abc winbindd[24723]: cm_prepare_connection: mutex grab
failed for ABC.typ.org <http://aklwindomp001.enterprisenet.org/>

Thanks
Amit

On 12/19/2018 01:23 PM, Rowland Penny via samba wrote:
> On Wed, 19 Dec 2018 12:32:45 +0530
> Amit Kumar via samba <samba at lists.samba.org> wrote:
>
>> Hey,
>>
>> But What's the reason of this error?
>>
> I do not know, but what I do know is that, if it is a bug, you will
> never get it fixed in Samba 4.2.x, this version is EOL. It might also
> have been fixed in a later version.
>
> Sorry if this isn't what you want to hear.
>
> Rowland
>

On Wed, 19 Dec 2018 13:37:34 +0530
Amit Kumar via samba <samba at lists.samba.org> wrote:
> Hey Rowland,
> 
> I wanted to ask
> 
> a. What is mutex.tdb, what is its purpose?
> 
> b. why "mutex grab failed" started appearing in messages, what
can be
> the probable reasons?
> 
> Is pre-authentication failed related to locking failure of mutex.tdb?
This is on red-hat isn't it ?
Have you considered that it might just be your sssd that might be at
fault ?

I repeat, you will not get this fixed in 4.2.x, it is EOL.

The bug, if it is a bug, may very well have been fixed in a later
version of Samba

Rowland

It looks like : 

https://bugzilla.samba.org/show_bug.cgi?id=11962 
> 
> a. What is mutex.tdb, what is its purpose?
A Mutex is a mutually exclusive flag. It acts as a gate keeper to a section of
code allowing one thread in and blocking access to all others.
> 
> b. why "mutex grab failed" started appearing in messages, what
can be
> the probable reasons?
Server to slow, dns responcing to slow, locking bugs in tdb. 
Things like that. 
> 
> Is pre-authentication failed related to locking failure of mutex.tdb?
Might be. 

> 
> 
> Dec 15 12:49:52 abc winbindd[30467]: [2018/12/15 12:49:52.764924, 0]
> ../source3/libsmb/cliconnect.c:1921(cli_session_setup_spnego_send)
> 
> Dec 15 12:49:52 abc winbindd[30467]: Kinit for ABC$@TYP.ORG
> <mailto:AKLRHEMPDP001$@ENTERPRISENET.ORG> to access
> cifs/xyz.fgb.net at xyz.NET
> <mailto:cifs/CVGWINDOMP011.securityroot.net at SECURITYROOT.NET>
failed:
> Preauthentication failed
> 
> ......

I suggest, test on one server my 4.8 package for jessie. 
If the 4.2 to 4.8 step is too big for you, choose a lower version. 
Info here:  https://apt.van-belle.nl/ 

Read : http://downloads.van-belle.nl/samba4/Upgrade-info.txt 
The most needed changes for smb.conf are summerized ni that file. 

And good to see redhat users use debian and ubuntu. ;-) 


Greetz, 

Louis