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
To safely mark a volume detached when the volume controller manager is used.
An example of one such problem:
1. pod is created, volume is added to desired state of the world
2. reconciler process starts
3. reconciler starts MountVolume, which is kicked off asynchronously via
operation_executor.go
4. MountVolume mounts the volume, but hasn't yet marked it as mounted
5. pod is deleted, volume is removed from desired state of the world
6. reconciler detects volume is no longer in desired state of world,
removes it from volumes in use
7. MountVolume tries to mark volume in use, throws an error because
volume is no longer in actual state of world list.
8. controller-manager tries to detach the volume, this fails because it
is still mounted to the OS.
9. EBS gets stuck indefinitely in busy state trying to detach.
Automatic merge from submit-queue
Curating Owners: pkg/volume
cc @jsafrane @spothanis @agonzalezro @justinsb @johscheuer @simonswine @nelcy @pmorie @quofelix @sdminonne @thockin @saad-ali @rootfs
In an effort to expand the existing pool of reviewers and establish a
two-tiered review process (first someone lgtms and then someone
experienced in the project approves), we are adding new reviewers to
existing owners files.
If You Care About the Process:
------------------------------
We did this by algorithmically figuring out who’s contributed code to
the project and in what directories. Unfortunately, that doesn’t work
well: people that have made mechanical code changes (e.g change the
copyright header across all directories) end up as reviewers in lots of
places.
Instead of using pure commit data, we generated an excessively large
list of reviewers and pruned based on all time commit data, recent
commit data and review data (number of PRs commented on).
At this point we have a decent list of reviewers, but it needs one last
pass for fine tuning.
Also, see https://github.com/kubernetes/contrib/issues/1389.
TLDR:
-----
As an owner of a sig/directory and a leader of the project, here’s what
we need from you:
1. Use PR https://github.com/kubernetes/kubernetes/pull/35715 as an example.
2. The pull-request is made editable, please edit the `OWNERS` file to
remove the names of people that shouldn't be reviewing code in the
future in the **reviewers** section. You probably do NOT need to modify
the **approvers** section. Names asre sorted by relevance, using some
secret statistics.
3. Notify me if you want some OWNERS file to be removed. Being an
approver or reviewer of a parent directory makes you a reviewer/approver
of the subdirectories too, so not all OWNERS files may be necessary.
4. Please use ALIAS if you want to use the same list of people over and
over again (don't hesitate to ask me for help, or use the pull-request
above as an example)
At master volume reconciler, the information about which volumes are
attached to nodes is cached in actual state of world. However, this
information might be out of date in case that node is terminated (volume
is detached automatically). In this situation, reconciler assume volume
is still attached and will not issue attach operation when node comes
back. Pods created on those nodes will fail to mount.
This PR adds the logic to periodically sync up the truth for attached volumes kept in the actual state cache. If the volume is no longer attached to the node, the actual state will be updated to reflect the truth. In turn, reconciler will take actions if needed.
To avoid issuing many concurrent operations on cloud provider, this PR
tries to add batch operation to check whether a list of volumes are
attached to the node instead of one request per volume.
More details are explained in PR #33760
Currently kubelet volume management works on the concept of desired
and actual world of states. The volume manager periodically compares the
two worlds and perform volume mount/unmount and/or attach/detach
operations. When kubelet restarts, the cache of those two worlds are
gone. Although desired world can be recovered through apiserver, actual
world can not be recovered which may cause some volumes cannot be cleaned
up if their information is deleted by apiserver. This change adds the
reconstruction of the actual world by reading the pod directories from
disk. The reconstructed volume information is added to both desired
world and actual world if it cannot be found in either world. The rest
logic would be as same as before, desired world populator may clean up
the volume entry if it is no longer in apiserver, and then volume
manager should invoke unmount to clean it up.
Automatic merge from submit-queue
pkg/various: plug leaky time.New{Timer,Ticker}s
According to the documentation for Go package time, `time.Ticker` and
`time.Timer` are uncollectable by garbage collector finalizers. They
leak until otherwise stopped. This commit ensures that all remaining
instances are stopped upon departure from their relative scopes.
Similar efforts were incrementally done in #29439 and #29114.
```release-note
* pkg/various: plugged various time.Ticker and time.Timer leaks.
```
Package goroutinemap can be structurally simplified to be more
idiomatic, concise, and free of error potential. No structural changes
are made.
It is unconventional declare `sync.Mutex` directly as a pointerized
field in a parent structure. The `sync.Mutex` operates on pointer
receivers of itself; and by relying on that, the types that contain
those fields can be safely constructed using
https://golang.org/ref/spec#The_zero_value.
The duration constants are already of type `time.Duration`, so
re-declaring that is redundant.
According to the documentation for Go package time, `time.Ticker` and
`time.Timer` are uncollectable by garbage collector finalizers. They
leak until otherwise stopped. This commit ensures that all remaining
instances are stopped upon departure from their relative scopes.
Allow mount volume operations to run in parallel for non-attachable
volume plugins.
Allow unmount volume operations to run in parallel for all volume
plugins.
