compute agent not cleaned up complemetely

[Lianhao Lu]

sometimes in devstack environment, the compute agent can not be cleaned up completely after unstack.

The remaining threads are:
$ ps aux | grep polling
stack 1621 0.0 0.0 11748 2200 pts/33 S+ 10:52 0:00 grep --color=auto polling
stack 27442 0.2 0.1 120236 48056 ? Ss Nov25 25:41 /usr/bin/python /usr/local/bin/ceilometer-polling --polling-namespaces compute --config-file /etc/ceilometer/ceilometer.conf
stack 27711 0.3 0.1 723284 64484 ? Sl Nov25 35:04 ceilometer-polling - AgentManager(0)

while a normal compute agent process spawned by devstack would be something like the following:
$ ps aux | grep polling
root 48633 0.0 0.0 15064 2056 pts/28 S+ 10:59 0:00 sg libvirtd /usr/local/bin/ceilometer-polling --polling-namespaces compute --config-file /etc/ceilometer/ceilometer.conf
stack 48635 11.6 0.1 120236 48064 ? Ss 10:59 0:01 /usr/bin/python /usr/local/bin/ceilometer-polling --polling-namespaces compute --config-file /etc/ceilometer/ceilometer.conf
stack 48850 1.6 0.1 722260 60508 ? Sl 10:59 0:00 ceilometer-polling - AgentManager(0)

seems the command issued by devstack's stop_process does not clean the compute agent, maybe because it is stared with

[gordon chung (chungg)]

i'm thinking either https://github.com/sileht/cotyledon/commit/64fea671bc167913a783b776e50f079642cad42f or https://github.com/sileht/cotyledon/commit/0addc9e99a55eecb23966772921c95c3b200001c fixed it.

regardless, it seemed fine the last few times i've tried. please reopen if needed.