[Samba] Odd Samba 4 ("4.2.0pre1-GIT-b505111"; actually only using client) behaviour #2 - "accept: Software caused connection abort".

[Volker Lendecke]

On Wed, Dec 11, 2013 at 04:36:44PM -0800, Richard Sharpe wrote:
> > # (dig one of the ECONNABORTED messages out; they're all of the same form)
> > ...
> > 224:    pollsys(0x08088D48, 8, 0xFEFFDF58, 0x00000000) (sleeping...)
> > 224:            fd=39 ev=POLLIN|POLLHUP rev=0
> > 224:            fd=38 ev=POLLIN|POLLHUP rev=0
> > 224:            fd=34 ev=POLLIN|POLLHUP rev=0
> > 224:            fd=36 ev=POLLIN|POLLHUP rev=0
> > 224:            fd=37 ev=POLLIN|POLLHUP rev=0
> > 224:            fd=35 ev=POLLIN|POLLHUP rev=0
> > 224:            fd=33 ev=POLLIN|POLLHUP rev=0
> > 224:            fd=6  ev=POLLIN|POLLHUP rev=0
> > 224:            timeout: 49.964000000 sec
> > 224:    pollsys(0x08088D48, 8, 0xFEFFDF58, 0x00000000)  = 1
> > 224:            fd=39 ev=POLLIN|POLLHUP rev=0
> > 224:            fd=38 ev=POLLIN|POLLHUP rev=0
> > 224:            fd=34 ev=POLLIN|POLLHUP rev=0
> > 224:            fd=36 ev=POLLIN|POLLHUP rev=0
> > 224:            fd=37 ev=POLLIN|POLLHUP rev=POLLIN
> > 224:            fd=35 ev=POLLIN|POLLHUP rev=0
> > 224:            fd=33 ev=POLLIN|POLLHUP rev=0
> > 224:            fd=6  ev=POLLIN|POLLHUP rev=0
> > 224:            timeout: 49.964000000 sec
> > 224:    accept(37, 0xFEFFDE0C, 0xFEFFDDF8, SOV_DEFAULT) Err#130 ECONNABORTED
> > ...
> > #
> >
> > So it's *always* happening on a socket listening on port 445, never on 139
> > (or any other port) and it's happening on *every* socket listening on port
> > 445 (3 interfaces, 3 sockets listening on that port).  That makes it
> > unlikely to be a resource issue (at client or server end) or it would be
> > unlikely to be that port specific, so perhaps some protocol corner-case?
> > Or, of course, just Solaris being moronic (wouldn't be unheard of ...)?
> >
> > I don't know whether that helps anyone at all?
> >
> > Cheers, and season's greetings (and all that ...),
> 
> We've seen this on FreeBSD. We increased the listen backlog to be the
> same as the system max and the messages went away.

Is the system doing this in a 100% busy loop, or is this
happening only under overload? Is smbd just not fast enough
accepting connections? Did the client do a RST while waiting
for smbd to do the accept()?

What does the system expect from an application as a proper
reply to this error message?

On FreeBSD, in listen(2) I read about kern.ipc.somaxconn,
which on 9.2 seems to default to 128. Is that the one we are
supposed to read?

Thanks,

Volker

-- 
SerNet GmbH, Bahnhofsallee 1b, 37081 Göttingen
phone: +49-551-370000-0, fax: +49-551-370000-9
AG Göttingen, HRB 2816, GF: Dr. Johannes Loxen
http://www.sernet.de, mailto:kontakt at sernet.de