openvswitch-agent spawning infinite number of ovsdb-client processes

[Dr. Jens Harbott]

After installing neutron on Ubuntu Xenial from the Newton UCA (2:9.0.0-0ubuntu1.16.10.2~cloud0), I noticed these processes:

neutron 11222 2.9 0.8 262628 108712 ? Ss 10:59 1:36 /usr/bin/python /usr/bin/neutron-openvswitch-agent --config-file=/etc/neutron/neutron.conf --config-file=/etc/neutron/plugins/ml2/openvswitch_agent.ini --log-file=/var/log/neutron/neutron-openvswitch-agent.lo
root 11686 0.0 0.0 54112 3256 ? S 11:00 0:00 \_ sudo neutron-rootwrap /etc/neutron/rootwrap.conf ovsdb-client monitor Interface name,ofport,external_ids --format=json
root 11688 0.0 0.3 83336 45444 ? S 11:00 0:00 | \_ /usr/bin/python /usr/bin/neutron-rootwrap /etc/neutron/rootwrap.conf ovsdb-client monitor Interface name,ofport,external_ids --format=json
root 11828 0.0 0.0 20056 2976 ? S 11:00 0:00 | \_ /usr/bin/ovsdb-client monitor Interface name,ofport,external_ids --format=json
root 13426 0.0 0.0 54112 3204 ? S 11:00 0:00 \_ sudo neutron-rootwrap /etc/neutron/rootwrap.conf ovsdb-client monitor Interface name,ofport,external_ids --format=json
root 13430 0.0 0.3 83336 45480 ? S 11:00 0:00 | \_ /usr/bin/python /usr/bin/neutron-rootwrap /etc/neutron/rootwrap.conf ovsdb-client monitor Interface name,ofport,external_ids --format=json
root 13490 0.0 0.0 20056 3052 ? S 11:00 0:00 | \_ /usr/bin/ovsdb-client monitor Interface name,ofport,external_ids --format=json
root 14775 0.0 0.0 54112 3256 ? S 11:01 0:00 \_ sudo neutron-rootwrap /etc/neutron/rootwrap.conf ovsdb-client monitor Interface name,ofport,external_ids --format=json
root 14779 0.0 0.3 83336 45272 ? S 11:01 0:00 | \_ /usr/bin/python /usr/bin/neutron-rootwrap /etc/neutron/rootwrap.conf ovsdb-client monitor Interface name,ofport,external_ids --format=json
root 14821 0.0 0.0 20056 2944 ? S 11:01 0:00 | \_ /usr/bin/ovsdb-client monitor Interface name,ofport,external_ids --format=json

with another set being spawned every 30 seconds. In /var/log/neutron/neutron-openvswitch-agent.log I see these errors:

2017-01-20 11:00:39.804 11222 ERROR neutron.agent.linux.async_process [-] Error received from [ovsdb-client monitor Interface name,ofport,external_ids --format=json]: sudo: unable to resolve host jr-ansi02
2017-01-20 11:00:39.805 11222 ERROR neutron.agent.linux.async_process [-] Process [ovsdb-client monitor Interface name,ofport,external_ids --format=json] dies due to the error: sudo: unable to resolve host jr-ansi02

Now of course one can claim that properly setting up sudo (or /etc/hosts rather) will solve this issue, but still maybe the ovs-agent process should properly clean up its children and not assume that they are dead as soon as there is any output to stderr (function _read_stderr() in neutron/agent/linux/async_process.py).