I also meet the bugs in celometer newton, when I configure ceilometer.conf

[notification]
workers = 2

the error log in /var/log/ceilometer/agent-notification.log:

2017-06-26 09:27:57.255 3781 INFO cotyledon._service [-] Caught SIGTERM signal, graceful exiting of service NotificationService(1) [3781]
2017-06-26 09:27:57.256 3783 INFO cotyledon._service [-] Caught SIGTERM signal, graceful exiting of service NotificationService(2) [3783]
2017-06-26 09:27:57.245 3780 ERROR cotyledon._utils [-] Unhandled exception
2017-06-26 09:27:57.245 3780 ERROR cotyledon._utils Traceback (most recent call last):
2017-06-26 09:27:57.245 3780 ERROR cotyledon._utils   File "/usr/lib/python2.7/site-packages/cotyledon/_utils.py", line 84, in exit_on_exception
2017-06-26 09:27:57.245 3780 ERROR cotyledon._utils     yield
2017-06-26 09:27:57.245 3780 ERROR cotyledon._utils   File "/usr/lib/python2.7/site-packages/cotyledon/_service.py", line 134, in _terminate
2017-06-26 09:27:57.245 3780 ERROR cotyledon._utils     self.terminate()
2017-06-26 09:27:57.245 3780 ERROR cotyledon._utils   File "/usr/lib/python2.7/site-packages/ceilometer/notification.py", line 309, in terminate
2017-06-26 09:27:57.245 3780 ERROR cotyledon._utils     super(NotificationService, self).terminate()
2017-06-26 09:27:57.245 3780 ERROR cotyledon._utils   File "/usr/lib/python2.7/site-packages/ceilometer/service_base.py", line 53, in terminate
2017-06-26 09:27:57.245 3780 ERROR cotyledon._utils     if self.refresh_pipeline_periodic:
2017-06-26 09:27:57.245 3780 ERROR cotyledon._utils AttributeError: 'NotificationService' object has no attribute 'refresh_pipeline_periodic'
2017-06-26 09:27:57.245 3780 ERROR cotyledon._utils 
2017-06-26 09:27:57.213 3785 ERROR cotyledon._utils [-] Unhandled exception
2017-06-26 09:27:57.213 3785 ERROR cotyledon._utils Traceback (most recent call last):
2017-06-26 09:27:57.213 3785 ERROR cotyledon._utils   File "/usr/lib/python2.7/site-packages/cotyledon/_utils.py", line 84, in exit_on_exception
2017-06-26 09:27:57.213 3785 ERROR cotyledon._utils     yield
2017-06-26 09:27:57.213 3785 ERROR cotyledon._utils   File "/usr/lib/python2.7/site-packages/cotyledon/_service.py", line 134, in _terminate
2017-06-26 09:27:57.213 3785 ERROR cotyledon._utils     self.terminate()
2017-06-26 09:27:57.213 3785 ERROR cotyledon._utils   File "/usr/lib/python2.7/site-packages/ceilometer/notification.py", line 309, in terminate
2017-06-26 09:27:57.213 3785 ERROR cotyledon._utils     super(NotificationService, self).terminate()
2017-06-26 09:27:57.213 3785 ERROR cotyledon._utils   File "/usr/lib/python2.7/site-packages/ceilometer/service_base.py", line 53, in terminate
2017-06-26 09:27:57.213 3785 ERROR cotyledon._utils     if self.refresh_pipeline_periodic:
2017-06-26 09:27:57.213 3785 ERROR cotyledon._utils AttributeError: 'NotificationService' object has no attribute 'refresh_pipeline_periodic'
2017-06-26 09:27:57.213 3785 ERROR cotyledon._utils 
2017-06-26 09:27:57.281 3783 ERROR cotyledon._utils [-] Unhandled exception
2017-06-26 09:27:57.281 3783 ERROR cotyledon._utils Traceback (most recent call last):
2017-06-26 09:27:57.281 3783 ERROR cotyledon._utils   File "/usr/lib/python2.7/site-packages/cotyledon/_utils.py", line 84, in exit_on_exception
2017-06-26 09:27:57.281 3783 ERROR cotyledon._utils     yield
2017-06-26 09:27:57.281 3783 ERROR cotyledon._utils   File "/usr/lib/python2.7/site-packages/cotyledon/_service.py", line 134, in _terminate
2017-06-26 09:27:57.281 3783 ERROR cotyledon._utils     self.terminate()
2017-06-26 09:27:57.281 3783 ERROR cotyledon._utils   File "/usr/lib/python2.7/site-packages/ceilometer/notification.py", line 309, in terminate
2017-06-26 09:27:57.281 3783 ERROR cotyledon._utils     super(NotificationService, self).terminate()
2017-06-26 09:27:57.281 3783 ERROR cotyledon._utils   File "/usr/lib/python2.7/site-packages/ceilometer/service_base.py", line 53, in terminate
2017-06-26 09:27:57.281 3783 ERROR cotyledon._utils     if self.refresh_pipeline_periodic:
2017-06-26 09:27:57.281 3783 ERROR cotyledon._utils AttributeError: 'NotificationService' object has no attribute 'refresh_pipeline_periodic'
2017-06-26 09:27:57.281 3783 ERROR cotyledon._utils 

I Strongely recommend to merge the patch.