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

[Andrew Bartlett]

On Fri, 2019-02-01 at 16:20 +0100, Stefan Metzmacher wrote:
> Hi,

> 
> Can this be a really busy gitlab shared runner that is swapping?

I was thinking something like that.  

Some of the shared runners are quite resource constrained, and any
python script that imports Samba's 'samba' python package will load
quite a bit of code due to the size of our bindings. 

Looking at the system-info.txt:

### free
             total       used       free     shared    buffers     cach
ed
Mem:       3784700     685648    3099052     169564       8636     3079
40
-/+ buffers/cache:     369072    3415628
Swap:      8388600     166420    8222180


This is after it finishes, but I would suggest that having pushed into
swap at all it is likely that the < 4GB of ram has already been
consumed.

> Does anyone has any idea?

I asked Joe to see if the imports could be made faster.

> Maybe giving samba_dnsupdate a 60 second timeout would be a workaround?

That could work, but I think the swap storm is likely to just hit
something else.

We can also split up samba-ad-dc-2 into samba-ad-dc-3 by putting the
backup and restore DCs tests in their own autobuild jobs.  This would
make sn-devel more busy (more complies) but be cheap on the shared
runners (free CI). 

Or we could rework selftest.pl to sort jobs by environment and shut
down the environment after the last job that needs it (as determined by
the dep tree we now have).  

How does that sound for medium and long-term plans?

Finally, I did merge Tim's patch to change the default process model,
so that will have changed the memory behaviour a lot. 

Andrew Bartlett
-- 
Andrew Bartlett                       http://samba.org/~abartlet/
Authentication Developer, Samba Team  http://samba.org
Samba Developer, Catalyst IT          http://catalyst.net.nz/services/samba