add rolling update / partial update support
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
Canonical Juju |
Triaged
|
Low
|
Unassigned | ||
Charm Helpers |
New
|
Undecided
|
Unassigned | ||
juju-core |
Won't Fix
|
Medium
|
Unassigned |
Bug Description
For the discussion below , "update" refers to upgrade-charm or config-change.
To add reliability to mission critical services, we should be able to do rolling updates ("update ok -> next"), and/or being able to partially update a subset of units.
E.g. use-case: ~1000 units cassandra restarting at the same time (think also: shared storage layer thundering effect).
E.g suggested usage:
$ juju upgrade-charm --max-in-flight=2 ...
Then to properly support resuming above (if interrupted)
$ juju upgrade-charm --num-units-
Then to complete either rollback:
$ juju upgrade-charm --roll-back ...
$ juju upgrade-charm --roll-forward ...
FYI webops currently has workarounded this at some charms by:
juju set units-to-
juju set units-to-update=all
Changed in juju-core: | |
status: | New → Triaged |
importance: | Undecided → High |
tags: | added: improvement upgrade-charm |
Changed in juju-core: | |
importance: | High → Medium |
tags: | added: canonical-bootstack |
ERRATA: at 1st post, it should obviously for 'upgrade-charm' (and likely 'set'), instead of 'deploy'.