[series-upgrade] "Series upgrade OpenStack" is wrong with respect to which unit to upgrade first
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
OpenStack Charms Deployment Guide |
Fix Released
|
High
|
Peter Matulis |
Bug Description
In HA, the guide indicates in the "Generalised OpenStack series upgrade" section:
The steps are as follows:
Set the default series for the principal application and ensure the same has been done to the model.
If hacluster is used, pause the hacluster units not associated with the principal leader machine.
Pause the principal non-leader units.
Perform a series upgrade on the principal leader machine.
If the operator does this then the service will be taken off-line.
In reality, the remaining machine (that is not paused) has the VIP and is continuing to provide a service. The operator should upgrade the two paused machines first, and when they are both on-line, one of them will claim the VIP. The 3rd machine's principle can then be paused, and upgraded.
In this way, service can be maintained during an upgrade.
Changed in charm-deployment-guide: | |
assignee: | nobody → Peter Matulis (petermatulis) |
importance: | Undecided → High |
status: | New → In Progress |
Alex, why do you say that after bringing the paused (and now upgraded) units back online one of them will claim the VIP? Wouldn't that happen only once:
1. the hacluster units associated with the now-upgraded principle units are resumed
and
2. the hacluster unit associated with the remaining (non-upgraded) unit is paused
Then the latter unit can be paused and upgraded?