Comment 0 for bug 1833069

During an upgrade, nova pins the version of RPC calls to the minimum seen across all services. This ensures that old services to not receive data they cannot handle. After the upgrade is complete, all nova services are supposed to be reloaded via SIGHUP to cause them to check again the RPC versions of services and use the new latest version which should now be supported by all running services.

Due to a bug [1] in oslo.service, sending services SIGHUP is currently broken. We replaced the HUP with a restart for the nova_compute container for bug 1821362, but not other nova services. It seems we need to restart all nova services to allow the RPC version pin to be removed.

[1] https://bugs.launchpad.net/oslo.service/+bug/1715374