samba_dnsupdate timeouts (was Re: [PATCH] python indent bugfix in dns_hub.py)

Stefan Metzmacher metze at samba.org
Thu Jan 31 17:39:07 UTC 2019


Am 24.01.19 um 19:44 schrieb Jeremy Allison via samba-technical:
> On Thu, Jan 24, 2019 at 12:48:03PM +0200, Isaac Boukris wrote:
>> Hi,
>>
>> On Wed, Jan 23, 2019 at 6:53 PM Jeremy Allison <jra at samba.org> wrote:
>>>
>>> Yeah, this is starting to look like something strange in your
>>> local environment.
>>
>> I think I figured out what's wrong in my environment. My main sin is
>> building with selftest only, without developer option. Though unlike
>> what I thought before, it wasn't due to timing but due to not using
>> the right resolv.conf file. Attached patch fixes it for me, please
>> take a look.
> 
> Hmmm. That looks correct to me, but I wonder how many
> other dependencies there are that assume DEVELOPER==ENABLE_SELFTEST.
> 
> Maybe we should just make one dependent on the other ?
> 
>> Unfortunately this does not help for the gitlab issues which do seem
>> timing related, as I think we always use developer option on gitlab.
>> Also note that after pushing the retry patch to my branch (merge
>> request 200), I still got a failure similar to the one Metze has
>> described, see:
>> https://gitlab.com/samba-team/devel/samba/-/jobs/150165046
>>
>> It was solved upon retrying, and I finally got the green mark.
> 
> Yeah, metze nailed the underlying cause I think,
> which is the interaction between dns_hub and the
> resolv wrapper. If I get time before FOSDEM I'll
> try and take a look.

It seems it has nothing todo with dns_hub at all.

It's just that samba_dnsupdate is so slow that it hits
the 20 seconds timeout and as a result we don't have our names
registered in the RESOLV_WRAPPER_HOSTS file.

I added a lot of debugging to it and run only samba-ad-dc-2 but 30 times
in a gitlab pipeline and I can reproduce the problem at least a few
times within these 30 jobs.

In this pipeline
https://gitlab.com/samba-team/devel/samba/pipelines/45603458
see
https://gitlab.com/samba-team/devel/samba/-/jobs/154237806

This (top) commit
https://git.samba.org/?p=metze/samba/wip.git;a=commitdiff;h=4a1ec1dcd566
with a few more:
https://git.samba.org/?p=metze/samba/wip.git;a=shortlog;h=4a1ec1dcd5669b
shows the problem

[2019/01/31 14:18:29.857643,  0, pid=28273] Calling DNS name update script
[2019/01/31 14:18:29.867998,  0, pid=28273] samba_runcmd_send: Started
process 28322 from 28273

...

[2019/01/31 14:18:30.030683,  0, pid=28273] python3: 2019/01/31
14:18:29.878457: before execvp() getpid(28322) getppid(28321) - stderr

...

[2019/01/31 14:18:45.883750,  0, pid=28273] python3: [2019/01/31
14:18:42.104352,  1, pid=28322] WARNING: The "server schannel" option is
deprecated
[2019/01/31 14:18:45.883976,  0, pid=28273] python3: INFO 2019-01-31
14:18:42,482 pid:28322
/tmp/samba-testbase/b17/samba-ad-dc-2/source4/scripting/bin/samba_dnsupdate
#113: IPs: ['127.0.0.17', 'fd00::5357:5f11']
[2019/01/31 14:18:45.884051,  0, pid=28273] python3: INFO 2019-01-31
14:18:42,658 pid:28322
/tmp/samba-testbase/b17/samba-ad-dc-2/source4/scripting/bin/samba_dnsupdate
#113: Start delay: 11.381402900000012


The startup of samba_dnsupdate takes 11 seconds for importing python
modules and similar things.

metze

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: OpenPGP digital signature
URL: <http://lists.samba.org/pipermail/samba-technical/attachments/20190131/883c0a04/signature.sig>


More information about the samba-technical mailing list