This PR changes behavior of the scheduler such that a task group with a
deployment that is failed or paused will not cause the scheduler to skip
migrations.
The reason for this change is that it causes a bad UX when draining
nodes with allocations that are part of a failed/paused deployment.
These operations should not be coupled in any way and this remedies
that.
Prior behavior was still correct, but required either jobs to
transistion to a healthy state or for the node to hit its drain
deadline.
This PR fixes:
* An issue in which a node-drain that contains a complete batch alloc
would cause a replacement
* An issue in which allocations with the same name during a scale
down/stop event wouldn't be properly stopped.
* An issue in which batch allocations from previous job versions may not
have been stopped properly.
Fixes https://github.com/hashicorp/nomad/issues/3210
This PR makes placing new allocations count towards the limit. We do not
restrict how many new placements are made by the limit but we still
count towards the limit. This has the nice affect that if you have a
group with count = 5 and max_parallel = 1 but only 3 allocs exist for it
and a change is made, you will create 2 more at the new version but not
destroy one, taking you down to two running as you would have
previously.
Fixes https://github.com/hashicorp/nomad/issues/3053
This PR allows the scheduler to replace lost allocations even if the job
has a failed or paused deployment. The prior behavior was confusing to
users.
Fixes https://github.com/hashicorp/nomad/issues/2958
This PR resolves a bug in which a job with multiple task groups would
create new deployment objects each, thus clearing out all other task
groups deployment state.
This PR fixes the rolling update limit calculation to avoid a panic when
there are more allocations for a deployment that haven't determined
their health than the max_parallel count of the task group.
Fixes https://github.com/hashicorp/nomad/issues/2820
