optimize adc.nodeUpdate(). Time complexity reduced from O(n) to O(1), where n is the number of nodes.
Data stored in nodeAttachedTo.mountedByNode is now at actualStateOfWorld.inUseVolumes.
This refactor also ensures that we can record the state update even if the volume is not present in ASW yet.
The added BenchmarkNodeUpdate result is reduced from 28076923 to 16030 ns/op.
The previous BenchmarkPopulateActualStateOfWorld result is also reduced from 13s to 8s.
Volume that failed Detach() should not be marked as attached, CSI
external-attacher is probably still trying to detach it.
Mark it uncertain instead and wait for Detach() to succeed.
6 minute force-deatch timeout should be used only for nodes that are not
healthy.
In case a CSI driver is being upgraded or it's simply slow, NodeUnstage
can take more than 6 minutes. In that case, Pod is already deleted from the
API server and thus A/D controller will force-detach a mounted volume,
possibly corrupting the volume and breaking CSI - a CSI driver expects
NodeUnstage to succeed before Kubernetes can call ControllerUnpublish.
During volume detach, the following might happen in reconciler
1. Pod is deleting
2. remove volume from reportedAsAttached, so node status updater will
update volumeAttached list
3. detach failed due to some issue
4. volume is added back in reportedAsAttached
5. reconciler loops again the volume, remove volume from
reportedAsAttached
6. detach will not be trigged because exponential back off, detach call
will fail with exponential backoff error
7. another pod is added which using the same volume on the same node
8. reconciler loops and it will NOT try to tigger detach anymore
At this point, volume is still attached and in actual state, but
volumeAttached list in node status does not has this volume anymore, and
will block volume mount from kubelet.
The fix in first round is to add volume back into the volume list that
need to reported as attached at step 6 when detach call failed with
error (exponentical backoff). However this might has some performance
issue if detach fail for a while. During this time, volume will be keep
removing/adding back to node status which will cause a surge of API
calls.
So we changed to logic to check first whether operation is safe to retry which
means no pending operation or it is not in exponentical backoff time
period before calling detach. This way we can avoid keep removing/adding
volume from node status.
Change-Id: I5d4e760c880d72937d34b9d3e904ecad125f802e
It is possible that by the time we check for multiattach
error on node, the reconciler loop may not have processed second
volume and hence we are going to retry for multiattach error
on node before giving up and marking the test as failed.
Only relying on the NewAttacher/Detacher call counts is not enough as they
happen in parallel to the testing/verification code and thus the actual
attaching/detaching may not be done yet, resulting in flaky test results.
Fixes#46244
When the attach/detach controller crashes and a pod with attached PV is deleted
afterwards the controller will never detach the pod's attached volumes. To
prevent this the controller should try to recover the state from the nodes
status.
