This PR adds two features:
1. add support for isolating the emptyDir volume use. If user
sets a size limit for emptyDir volume, kubelet's eviction manager
monitors its usage
and evict the pod if the usage exceeds the limit.
2. add support for isolating the local storage for container overlay. If
the container's overly usage exceeds the limit defined in container
spec, eviction manager will evict the pod.
This PR adds the check for local storage request when admitting pods. If
the local storage request exceeds the available resource, pod will be
rejected.
This PR adds the support for allocatable local storage (scratch space).
This feature is only for root file system which is shared by kubernetes
componenets, users' containers and/or images. User could use
--kube-reserved flag to reserve the storage for kube system components.
If the allocatable storage for user's pods is used up, some pods will be
evicted to free the storage resource.
Automatic merge from submit-queue (batch tested with PRs 45488, 45335, 45909, 46074, 46615)
Fix screwed-up log message format
It had two %-verbs and three arguments
**What this PR does / why we need it**:
Fixes kubelet log lines like this:
May 08 11:49:04 brya-1 kubelet[23248]: W0508 11:49:04.248123 23248 eviction_manager.go:128] Failed to admit pod kube-proxy-g3hjs_kube-system(55c1fbbb-33e4-11e7-b83c-42010a800002) - node has conditions: %v%!(EXTRA []v1.NodeConditionType=[MemoryPressure])
to remove the `%v%!(EXTRA`
**Release note**:
```release-note
NONE
```
Automatic merge from submit-queue (batch tested with PRs 46501, 45944, 46473)
fix func comment in helpers.go
**What this PR does / why we need it**:
fix func comment in helpers.go
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #
NONE
**Special notes for your reviewer**:
NONE
**Release note**:
```release-note
NONE
```
Automatic merge from submit-queue (batch tested with PRs 46022, 46055, 45308, 46209, 43590)
Eviction does not evict unless the previous pod has been cleaned up
Addresses #43166
This PR makes two main changes:
First, it makes the eviction loop re-trigger immediately if there may still be pressure. This way, if we already waited 10 seconds to delete a pod, we dont need to wait another 10 seconds for the next synchronize call.
Second, it waits for the pod to be cleaned up (including volumes, cgroups, etc), before moving on to the next synchronize call. It has a timeout for this operation currently set to 30 seconds.
Automatic merge from submit-queue
Moved qos to api.helpers.
**What this PR does / why we need it**:
The `GetPodQoS` is also used by other components, e.g. kube-scheduler and it's not bound to kubelet; moved it to api helpers so client-go.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #N/A
**Release note**:
```release-note-none
```
Automatic merge from submit-queue (batch tested with PRs 42369, 42375, 42397, 42435, 42455)
[Bug Fix]: Avoid evicting more pods than necessary by adding Timestamps for fsstats and ignoring stale stats
Continuation of #33121. Credit for most of this goes to @sjenning. I added volume fs timestamps.
**why is this a bug**
This PR attempts to fix part of https://github.com/kubernetes/kubernetes/issues/31362 which results in multiple pods getting evicted unnecessarily whenever the node runs into resource pressure. This PR reduces the chances of such disruptions by avoiding reacting to old/stale metrics.
Without this PR, kubernetes nodes under resource pressure will cause unnecessary disruptions to user workloads.
This PR will also help deflake a node e2e test suite.
The eviction manager currently avoids evicting pods if metrics are old. However, timestamp data is not available for filesystem data, and this causes lots of extra evictions.
See the [inode eviction test flakes](https://k8s-testgrid.appspot.com/google-node#kubelet-flaky-gce-e2e) for examples.
This should probably be treated as a bugfix, as it should help mitigate extra evictions.
cc: @kubernetes/sig-storage-pr-reviews @kubernetes/sig-node-pr-reviews @vishh @derekwaynecarr @sjenning
Automatic merge from submit-queue (batch tested with PRs 41074, 41147, 40854, 41167, 40045)
Add debug logging to eviction manager
**What this PR does / why we need it**:
This PR adds debug logging to eviction manager.
We need it to help users understand when/why eviction manager is/is not making decisions to support information gathering during support.
Chao Xu