[Samba] kcc_periodic output

[Douglas Bagnall]

On 8/02/24 11:17, Elias Pereira wrote:
> Hi Douglas, thanks for the answer!!!
> 
>     samba kcc command = /path/to/samba_kcc --debug
> 
> 
> I ran the command and the result is in the pastebin below, if you can 
> take a look.
> https://pastebin.com/x6W2yWm7 <https://pastebin.com/x6W2yWm7>

It looks to me like that was a successful run, but I can't see if it was 
slow.

If I understand correctly, sometimes it is bad, and sometimes it is not.
If you run in a loop, something like

for i in $(seq 1 10); do time /usr/sbin/samba_kcc --debug; sleep 5;done

then you might find one that takes more than 40 seconds -- that is the 
NT_STATUS_IO_TIMEOUT.

Douglas


> 
>     But anyway, I don't think this is a samba_kcc specific problem, and
>     https://bugzilla.samba.org/show_bug.cgi?id=15568
>     <https://bugzilla.samba.org/show_bug.cgi?id=15568>is due to the same
>     underlying issue. I don't know what that is.
> 
> 
> I opened this bug, but no one has replied yet.
> 
>     >> UpdateRefs failed with NT_STATUS_IO_TIMEOUT
>     This is a different replication failure, independent of the KCC.
>     samba_kcc works out where the DC should replicate from, and the drepl
>     code does the actual replication.
>     Both could fail with network weirdness, or if either the local or remote
>     database is locked up for some reason.
> 
> 
> And how can I debug this problem? I've searched everywhere and found 
> nothing about it.
> 
> On Wed, Feb 7, 2024 at 6:40 PM Douglas Bagnall 
> <douglas.bagnall at catalyst.net.nz 
> <mailto:douglas.bagnall at catalyst.net.nz>> wrote:
> 
>     On 8/02/24 02:11, Elias Pereira via samba wrote:
>      > Any idea how I can debug this?
> 
> 
>      >>> I don't know the answer to that, but I think setting
>      >>>
>      >>>       samba kcc command = /usr/sbin/samba_kcc -d5
>      >>>
> 
>     I looked it up. Actually
> 
>              samba kcc command = /path/to/samba_kcc --debug
> 
>     *might* produce more interesting results (you'll probably want to use
>     `less -R` to view the logs).
> 
>     You can run samba_kcc independently -- it should not do any harm, but
>     you can use the --readonly flag if you want to be careful.
> 
>     But anyway, I don't think this is a samba_kcc specific problem, and
>     https://bugzilla.samba.org/show_bug.cgi?id=15568
>     <https://bugzilla.samba.org/show_bug.cgi?id=15568>
>     is due to the same underlying issue. I don't know what that is.
> 
>      >> [2024/02/02 20:05:17.752322,  0]
>      >>
>     ../../source4/dsdb/repl/drepl_out_helpers.c:1300(dreplsrv_update_refs_done)
>      >>    UpdateRefs failed with NT_STATUS_IO_TIMEOUT
> 
>     This is a different replication failure, independent of the KCC.
> 
>     samba_kcc works out where the DC should replicate from, and the drepl
>     code does the actual replication.
> 
>     Both could fail with network weirdness, or if either the local or
>     remote
>     database is locked up for some reason.
> 
>      >> What does this part of the code do?
>      >> source4/dsdb/kcc/kcc_periodic.c:790
> 
>     That just reports that samba_kcc failed.
> 
>     cheers,
>     Douglas
> 
> 
> 
> -- 
> Elias Pereira