Comment 27 for bug 1405549

I applied https://review.openstack.org/#/c/167863/ to iso #234

Results:

201 0.113 -- three controllers active
201 0.171
201 0.119
201 0.165
201 0.108
201 0.092
201 0.099
201 0.097
201 0.106
201 0.201
201 0.113
201 3.125 -- master controller shutting down
201 4.114
503 40.006
201 1.103
201 1.094
201 4.104
201 4.102
201 0.118 -- normalization of delays after 20-30 seconds (only two controllers active)
201 0.091
201 0.103
201 0.135
201 0.092
201 0.143
201 0.102

Seems patch works for me.