Comment 37 for bug 1596075

attached.
I changed:
log_dir = /var/log/neutron
log_file = neutron.log
use_stderr = false

and restarted the 3 neutron api.

Note the error reported to heat was different:
Resource CREATE failed: DBDeadlock: resources.sn0: (pymysql.err.InternalError) (1213, u'Deadlock found when trying to get lock; try restarting transaction')

but there is still the overlaps failure:

Validation for CIDR: 172.16.41.0/24 failed - overlaps with subnet 0bce614f-9ad4-4602-96ec-fa22a3508d7c (CIDR: 172.16.41.0/24)

in the pcap, i made it not just port 9696 (so u can see the mysql too). I decoded to text, but this is likely easier viewed in wireshark with 'follow' on the port 3306 vs 9696