Seems some machines didn't start/finish commissioning like the other ones as I saw this issue:
-02-23 12:10:28+0800 [TFTP (UDP)] Datagram received from ('192.168.10.254', 49153): <RRQDatagram(filename=b'/boot/isolinux/ldlinux.c32', mode=b'octet', options=OrderedDict([(b'tsize', b'0'), (b'blksize', b'1408')]))>
2016-02-23 12:10:40+0800 [TFTP (UDP)] Datagram received from ('192.168.10.254', 49160): <RRQDatagram(filename=b'pxelinux.cfg/01-74-d4-35-89-bc-23', mode=b'octet', options=OrderedDict([(b'tsize', b'0'), (b'blksize', b'1408')]))>
2016-02-23 12:10:40+0800 [HTTPPageGetter,client] RemoteOriginReadSession starting on 53521
2016-02-23 12:10:40+0800 [HTTPPageGetter,client] Starting protocol <tftp.bootstrap.RemoteOriginReadSession object at 0x7f4311638320>
2016-02-23 12:10:40+0800 [RemoteOriginReadSession (UDP)] (UDP Port 53521 Closed)
2016-02-23 12:10:40+0800 [RemoteOriginReadSession (UDP)] Stopping protocol <tftp.bootstrap.RemoteOriginReadSession object at 0x7f4311638320>
2016-02-23 12:10:41+0800 [-] Unhandled Error
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/twisted/application/app.py", line 364, in startReactor
self.config, oldstdout, oldstderr, self.profiler, reactor)
File "/usr/lib/python3/dist-packages/twisted/application/app.py", line 285, in runReactorWithLogging
reactor.run()
File "/usr/lib/python3/dist-packages/twisted/internet/base.py", line 1194, in run
self.mainLoop()
File "/usr/lib/python3/dist-packages/twisted/internet/base.py", line 1203, in mainLoop
self.runUntilCurrent()
--- <exception caught here> ---
File "/usr/lib/python3/dist-packages/twisted/internet/base.py", line 825, in runUntilCurrent
call.func(*call.args, **call.kw)
File "/usr/lib/python3/dist-packages/tftp/util.py", line 81, in _call_and_schedule
self.callable(*self.callable_args, **self.callable_kwargs)
File "/usr/lib/python3/dist-packages/twisted/internet/udp.py", line 268, in write
return self.socket.send(datagram)
builtins.AttributeError: 'Port' object has no attribute 'socket'
[...]
2016-02-23 12:13:33+0800 [TFTP (UDP)] Datagram received from ('192.168.10.254', 49155): <RRQDatagram(filename=b'/boot/syslinux/ldlinux.c32', mode=b'octet', options=OrderedDict([(b'tsize', b'0'), (b'blksize', b'1408')]))>
2016-02-23 12:13:37+0800 [TFTP (UDP)] Datagram received from ('192.168.10.254', 49155): <RRQDatagram(filename=b'/boot/syslinux/ldlinux.c32', mode=b'octet', options=OrderedDict([(b'tsize', b'0'), (b'blksize', b'1408')]))>
2016-02-23 12:13:42+0800 [TFTP (UDP)] Datagram received from ('192.168.10.254', 49155): <RRQDatagram(filename=b'/boot/syslinux/ldlinux.c32', mode=b'octet', options=OrderedDict([(b'tsize', b'0'), (b'blksize', b'1408')]))>
2016-02-23 12:13:48+0800 [TFTP (UDP)] Datagram received from ('192.168.10.254', 49155): <RRQDatagram(filename=b'/boot/syslinux/ldlinux.c32', mode=b'octet', options=OrderedDict([(b'tsize', b'0'), (b'blksize', b'1408')]))>
2016-02-23 12:13:56+0800 [TFTP (UDP)] Datagram received from ('192.168.10.254', 49155): <RRQDatagram(filename=b'/boot/syslinux/ldlinux.c32', mode=b'octet', options=OrderedDict([(b'tsize', b'0'), (b'blksize', b'1408')]))>
2016-02-23 12:14:05+0800 [TFTP (UDP)] Datagram received from ('192.168.10.254', 49155): <RRQDatagram(filename=b'/boot/syslinux/ldlinux.c32', mode=b'octet', options=OrderedDict([(b'tsize', b'0'), (b'blksize', b'1408')]))>
2016-02-23 12:14:15+0800 [TFTP (UDP)] Datagram received from ('192.168.10.254', 49155): <RRQDatagram(filename=b'/boot/syslinux/ldlinux.c32', mode=b'octet', options=OrderedDict([(b'tsize', b'0'), (b'blksize', b'1408')]))>
=====
TFTP Request - pxelinux.cfg/01-74-d4-35-89-bc-3b Tue, 23 Feb. 2016 11:58:22
TFTP Request - pxelinux.cfg/3bbc8935-d474-8001-e311-1ea200eefb38 Tue, 23 Feb. 2016 11:58:22
TFTP Request - ubuntu/amd64/generic/xenial/daily/boot-kernel Tue, 23 Feb. 2016 11:58:22
TFTP Request - pxelinux.cfg/01-74-d4-35-89-bc-3b Tue, 23 Feb. 2016 11:58:22
TFTP Request - /syslinuxldlinux.c32 Tue, 23 Feb. 2016 11:58:22
TFTP Request - /boot/isolinux/ldlinux.c32 Tue, 23 Feb. 2016 11:58:22
TFTP Request - /syslinux/ldlinux.c32 Tue, 23 Feb. 2016 11:58:22
TFTP Request - /boot/syslinux/ldlinux.c32 Tue, 23 Feb. 2016 11:58:22
TFTP Request - /syslinux/ldlinux.c32 Tue, 23 Feb. 2016 11:58:22
TFTP Request - ldlinux.c32 Tue, 23 Feb. 2016 11:58:22
TFTP Request - pxelinux.0 Tue, 23 Feb. 2016 11:58:21
TFTP Request - /isolinux/ldlinux.c32 Tue, 23 Feb. 2016 11:58:22
TFTP Request - pxelinux.0 Tue, 23 Feb. 2016 11:58:21
PXE Request - commissioning Tue, 23 Feb. 2016 11:58:22
PXE Request - commissioning Tue, 23 Feb. 2016 11:58:22
Node powered on Tue, 23 Feb. 2016 11:56:43
This error shows up for me at the very end of deployment. The node still reaches the "Deployed" state, but this exception is being raised.