Perform StatefulSets deletions before replicas downscale #2062
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We had a bug where a StatefulSet with 0 replicas could be kept forever under particular conditions (eg. cannot be removed since there is a risk to remove the last master node... even though there is 0 replicas). This commit fixes it by decoupling StatefulSets deletions from StatefulSet downscales. A StatefulSet deletion is only performed when the actual StatefulSet has 0 replicas. Our expectations mechanism ensures there is no Pod still alive for that StatefulSet (eg. if it was just downscaled from 1 to 0 replicas). So that StatefulSet can be safely garbage-collected. StatefulSets deletions are now ran before handling downscales, regardless of any downscale invariant constraint. The downscale code is a bit simplified since it does not need to handle StatefulSets deletions anymore.
david-kow
approved these changes
Oct 28, 2019
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We had a bug where a StatefulSet with 0 replicas could be kept forever
under particular conditions (eg. cannot be removed since there is a risk
to remove the last master node... even though there is 0 replicas).
This commit fixes it by decoupling StatefulSets deletions from
StatefulSet downscales.
A StatefulSet deletion is only performed when the actual StatefulSet has
0 replicas. Our expectations mechanism ensures there is no Pod still
alive for that StatefulSet (eg. if it was just downscaled from 1 to 0
replicas). So that StatefulSet can be safely garbage-collected.
StatefulSets deletions are now ran before handling downscales,
regardless of any downscale invariant constraint.
The downscale code is a bit simplified since it does not need to handle
StatefulSets deletions anymore.
Fixes #2009 and the TestMutationMdiToDedicated E2E test.