3 - With expirer deprecated and disabled by default, there is an upgrade
4 impact here. If you had expirer enabled in ocata and you upgrade to
5 pike the expirer will not be enabled anymore. If you wish to use
6 expirer, ensure you include the ceilometer-expirer.yaml
7 to your upgrade deploy command. Also note that with collector
8 disabled, there is no need for expirer to be running.
10 - Deprecate and turn off expirer service as collector. Without collector
11 and standard storage, expirer has no use.