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.
- actual_state_of_world_test.go: test the new method GetVolumesToReportAttachedForNode
for an existing node and a non-existing node
- node_status_updater_test.go: test UpdateNodeStatuses and UpdateNodeStatuses in nominal
case with 2 nodes getting one volume each. Test UpdateNodeStatuses with the first call
to node.patch failing but the following one succeeding
- add comment in node_status_updater.go
- fix log line in reconciler.go
- rename variable in actual_state_of_world.go
The UpdateNodeStatuses code stops too early in case there is
an error when calling updateNodeStatus. It will return immediately
which means any remaining node won't have its update status put back
to true.
Looking at the call sites for UpdateNodeStatuses, it appears this is
not the only issue. If the lister call fails with anything but a Not Found
error, it's silently ignored which is wrong in the detach path.
Also the reconciler detach path calls UpdateNodeStatuses but the real intent
is to only update the node currently processed in the loop and not proceed
with the detach call if there is an error updating that specifi node volumesAttached
property. With the current implementation, it will not proceed if there is
an error updating another node (which is not completely bad but not ideal) and
worse it will proceed if there is a lister error on that node which means the
node volumesAttached property won't have been updated.
To fix those issues, introduce the following changes:
- [node_status_updater] introduce UpdateNodeStatusForNode which does what
UpdateNodeStatuses does but only for the provided node
- [node_status_updater] if the node lister call fails for anything but a Not
Found error, we will return an error, not ignore it
- [node_status_updater] if the update of a node volumesAttached properties fails
we continue processing the other nodes
- [actual_state_of_world] introduce GetVolumesToReportAttachedForNode which
does what GetVolumesToReportAttached but for the node whose name is provided
it returns a bool which indicates if the node in question needs an update as
well as the volumesAttached list. It is used by UpdateNodeStatusForNode
- [actual_state_of_world] use write lock in updateNodeStatusUpdateNeeded, we're
modifying the map content
- [reconciler] use UpdateNodeStatusForNode in the detach loop
In the following code pattern, the log message will get logged with v=0 in JSON
output although conceptually it has a higher verbosity:
if klog.V(5).Enabled() {
klog.Info("hello world")
}
Having the actual verbosity in the JSON output is relevant, for example for
filtering out only the important info messages. The solution is to use
klog.V(5).Info or something similar.
Whether the outer if is necessary at all depends on how complex the parameters
are. The return value of klog.V can be captured in a variable and be used
multiple times to avoid the overhead for that function call and to avoid
repeating the verbosity level.
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
- Move from the old github.com/golang/glog to k8s.io/klog
- klog as explicit InitFlags() so we add them as necessary
- we update the other repositories that we vendor that made a similar
change from glog to klog
* github.com/kubernetes/repo-infra
* k8s.io/gengo/
* k8s.io/kube-openapi/
* github.com/google/cadvisor
- Entirely remove all references to glog
- Fix some tests by explicit InitFlags in their init() methods
Change-Id: I92db545ff36fcec83afe98f550c9e630098b3135
