The HPA controller keeps a flat history of recommendations for
stabilization. However when both up and down scale stabilization are
configured, the interpretation of the history changes depending on the
direction of movement. What we want is to keep the stabilized
recommendation within the envelope of the minimum and maximum over
configured stabilization windows. We should only move when the
envelope forces a move.
The range allocator in pkg/controller/nodeipam/ipam/range_allocator.go
may call Occupy() on the same range twice:
1. Just before subscribing to the NodeInformer
2. From a callback given to the NodeInformer soon after registration
Adds unit tests covering the problematic scenarios identified
around conflicting data in child owner references
Before After
package level 51% 68%
garbagecollector.go 60% 75%
graph_builder.go 50% 81%
graph.go 50% 68%
Added/improved coverage of key functions that had lacking unit test coverage:
* attemptToDeleteWorker
* attemptToDeleteItem
* processGraphChanges (added coverage of all added code)
If a cluster-scoped dependent references a namespace-scoped owner,
this is an invalid relationship, and the lookup will never succeed in attemptToDelete.
Short-circuit requeueing in attemptToDelete and log.
When we observe valid coordinates for a previously virtual node,
if there are dependents that do not agree with those coordinates,
add them to the attemptToDelete queue.
This queue will check the dependent's ownerReferences using the coordinates specified by the dependent.
If all of the owners can be verified absent, the dependent will be deleted.
If some are still present, or if there are errors looking them up, the dependent will not be deleted.
If the verified owner is namespaced, and the dependent is not in the same namespace,
an event will be recorded for user visibility, since cross-namespace ownerReferences are not supported.
If a virtual delete event is received for a node whose dependents disagree on the parent's coordinates:
1. propagate the delete to children that matched the verified absent coordinates
2. if the existing node is virtual, select a new set of coordinates from the remaining dependents
3. do not delete the parent node from the graph if the parent node is non-virtual,
or if there are dependents that do not agree with the virtual delete event coordinates
When adding a dependent to the graph, we ensure there is a node representing each owner reference,
and add the dependent to each parent node.
If the parent node already exists, and the dependent's ownerReference
coordinates disagree with the verified coordinates, add the dependent to the attemptToDelete queue.
This queue will check the dependent's ownerReferences using the coordinates specified by the dependent.
If all of the owners can be verified absent, the dependent will be deleted.
If some are still present, or if there are errors looking them up, the dependent will not be deleted.
If the parent node has been observed via informer event (so we know the coordinates are accurate),
and the verified owner is namespaced, and the dependent is not in the same namespace,
an event will be recorded for user visibility, since cross-namespace ownerReferences are not supported.
Virtual nodes are added to the attemptToDelete queue, and continue getting requeued
until they are successfully verified absent or are observed via informer.
In the meantime, if the real object associated with that UID is observed via informer,
or is observed to be deleted via informer, the graph node for that UID can be removed
or marked as observed. In that case, we should stop retrying to get the virtual node coordinates.
